HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
HSC Chemistry Notes:




Module 5: Equilibrium and Acid Reactions
Module 6: Acid and Base Reactions
Module 7: Organic Chemistry
Module 8: Applying Chemical Ideas
Module 5: Equilibrium and Acid Reactions
Static and Dynamic Equilibrium
Reversibility of chemical reactions:
Formation of hydrated and dehydrated cobalt (II) chloride:
Dehydrated cobalt (II) chloride + water ⇌ hydrated cobalt (II) chloride
CoCl2 + 6H2O ⇌ CoCl2∙6H2O
Blue

pink
When the hydrated cobalt (II) chloride is heated, it becomes blue again as the water evaporated.
Reaction of Iron (III) nitrate and potassium thiocyanate:
Iron (III) nitrate + potassium thiocyanate ⇌ iron (iii) thiocyanate
Fe3+(aq) + SCN-(aq) ⇌ FeSCN2+(aq)
Pale yellow


colourless
red
When (Fe (NO3)3) and (KSCN) are mixed, they form a red-coloured ion, iron (III) thiocyanate
Is a reversible reaction and forms an equilibrium
Burning Magnesium:
2Mg(s) + O2  2MgO(s)

An irreversible combustion reaction, releasing energy into the system, producing white magnesium
oxide.
Burning Steel Wool:
3
2Fe (s) + O2 (g)  Fe2O3 (s)
2


pg. 1
An irreversible reaction and is a combustion reaction.
As the steel wool caught on fire and went red with sparks flying out.
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Static and dynamic equilibrium and differences between closed and open systems:
Equilibrium: A situation in which both the forward and reverse reaction are equal in a closed system.
Reversible reaction: Reaction that can proceed in either direction depending on the prevailing conditions,
reaction that can go backwards.
Characteristics of equilibrium:
 At chemical equilibrium, the rate of forward and reverse reactions is equal.
 Occurs in a closed system
 The position of equilibrium is not affected by a catalyst
 The concentrations of the reactants and products reach constant values at equilibrium
 Change is occurring at a microscopic level, atoms and molecules are constantly changing
Homogenous equilibrium: refers to a state of equilibrium in which all the involved species (reactants and
products) are in the same state/phase.
 CH3COOH (aq) ⇌ CH3COO-(aq) + H+(aq)
Heterogenous equilibrium: A reaction in which the substances are in different states.
 NiCl2(s) ⇌ Ni2+(aq) + 2Cl-(aq)
Static Equilibrium:
Static equilibrium: Occurs when the rates of the forward and reverse reactions both are equal to zero.


Occurs when nothing is happening in a reaction and the equilibrium of system is at rest.
- E.g. Conversion of graphite into diamond is considered is at a static equilibrium C (diamond) ⇌ C
(graphite) When at room temperature, neither reaction can be seen.
A limiting reagent reaction is another example of static equilibrium, once the limiting reagent has
been used up, neither the forward nor reverse reaction will occur.
Dynamic Equilibrium:
Dynamic equilibrium: refers to a system, in which the rate of the forward reaction is equal to the rate of the
reverse reactions as they are occurring at the same time and rate, so no net change.



pg. 2
No observable change occurs, but the forward and reverse reactions are occurring at an atomic
level.
- E.g. Two people shovelling dirt into each other’s piles at the same rate. Piles stay the same, but
both are still shovelling.
System needs to be closed for a dynamic equilibrium and is a type of a steady state but not all steady
states are in equilibrium.
Reaction between hydrogen and nitrogen is a reversible reaction that reaches dynamic equilibrium
in closed container:
3H2(g) + N2(g) ⇌ 2NH3(g)
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Steady State:
Steady state is not always an equilibrium and can be achieved without a reversible reaction or a closed
system.
 E.g. water is flowing into a sink and out of a sink at the same rate this is a steady state. The water
level in the sink may ready constant and so this is a steady state, however, as there is matter and
energy entering and leaving the system, not an equilibrium.
Open System:
Open System: A chemical system in which energy and matter can be exchanged by its surroundings (external
environment).
Closed System:
Closed system: a chemical system that does not allow the flow of matter between the system and
environment, only energy can be exchanged.
Non-equilibrium system in terms of effect on entropy and enthalpy:
Non-equilibrium system: A system that is not at equilibrium and can never reach an equilibrium state. These
reactions involving such systems are considered irreversible.
Irreversible reaction: reactions that go to completion, products cannot be turned back into reactants.
Two types of non-equilibrium reactions include;
 Combustion reaction
 Photosynthesis reaction
pg. 3
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Combustion Reactions:
 Combustion reactions are irreversible exothermic reaction that involves combining of a substance
with oxygen.
 Reaction is in one direction, products cannot reverse back into reactants
 Enthalpy of combustion is always negative as energy is always released into the environment.
 Most combustion reactions occur spontaneously, especially when entropy is increasing. Both
entropy and enthalpy are drivers of combustion.
Photosynthesis Reactions:
 A reaction by which plants transform light energy into chemical energy due to green pigment
chlorophyll
 Photosynthesis is a photochemical process which is an endothermic chemical process and involves
the reduction of carbon.
 Photosynthesis consists of a series of reaction steps, but overall reaction be shown by equation
below:
sunlight
6CO2(g)
+
6H2O(l) → C6H12O6(aq) + 6O2(g)
chlorophyll


Not a spontaneous reaction as energy of the products is greater than the energy of reactants
Whilst respiration looks like the reverse of photosynthesis, neither are reversible reactions,
each go to complete and do not reach equilibrium.
Collision Theory and Reaction Rate:
Collison theory is a model that explains how reactions occur when particles collide and is dependent on the;
pg. 4
HSC Chemistry Notes
-

Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Frequency of collisions
The orientations of the
particles
Amount of energy required to
break the bond (activation
energy) and the size of
activation energy would affect
likeness of reaction proceeding
Reversibility of chemical reactions
is related to the activation energies
of forward and reverse reactions
Reaction Rate:
Reaction rate is the speed at which a
chemical reaction occurs – the speed at
which reactants are used and products are
formed.
Reaction rate can also be influenced by:
 Concentration of reactants
 Temperature of surroundings
 Structure of reacting particles
 Pressure
 Presence or absence of a catalyst
Factors that Affect
Equilibrium:
Le Chatelier’s Principle Prac:
Le Chatelier’s principle states that ‘if an equilibrium system is subjected to a change, the system will adjust
itself to partially oppose the effect of the change’.


Equilibrium will always shift in the direction which counteracts the change that disturbed it in the
first place  a new equilibrium will be established
Also predicts how an equilibrium will respond to a disturbance.
For any equilibrium system, the position of equilibrium may be change by:
 Temperature altered
 Total pressure change/volume
 Concentration/pressure of species changed
 Dilution (for an equilibrium in solution)
Changes in Temperature:
 If an equilibrium reaction is cooled, it will react to increase the temperature to raise it towards its
original value, minimising change and so decreasing the temperature favour the exothermic reaction
(reaction that releases heat).
 If the temperature of a system is increased, the endothermic reaction will be favoured (reaction that
used heat).
pg. 5
HSC Chemistry Notes

Yr 12 Chemistry
By Tayyab Awais
23/02/2022
E.g. N2O4 (g) ⇌ 2NO2 (g) ∆H= +ve
- The forward reaction absorbs heat and the reverse reaction releases heat.
- If the temperature is increased, then the forward reaction would be favoured and so [NO2]
would increase and [N2O4] would decrease.
Changes in Concentration:
 Change in concentration of reactants or products.
 Increasing the concentration of the reactants, LCP states that the system will adjust to minimise the
changes so the forward reaction will be favoured in order to use up the reactants  decreases
concentration close to original value.
 Increase in products causes a shift to the left (towards reactants)

E.g. 2O4 (g) ⇌ 2NO2 (g) ΔH=+ve
- If increase [N2O4] then the forward reaction occurs at a greater rate to decrease [N2O4] and
increase [NO2].
- If increase [NO2] then the reverse reaction occurs to decrease [NO2] and increase [N2O4].
Changes in pressure:
 When increasing the pressure (decreasing volume) of an equilibrium system, according to LCP, the
side that has the fewer moles of gas  equilibrium will shift and favour that side
 Decreasing the pressure (increasing volume) of an equilibrium system, according to the LCP, the side
that has a greater amount of moles will be favoured  equilibrium will shift and favour that side

E.g. N2O4 (g) ⇌ 2NO2 (g) ΔH=+ve
- If volume is halved by doubling the pressure, then concentration of particles is increased.
Equilibrium will be re-established by decreasing concentration of gaseous particles. The reverse
reaction would be favoured as for every two molecules of NO2 that react only one of N2O4 is
produced. Therefore leading to a decrease in the total number of particles.

Where equilibrium system contains equal numbers of gaseous molecules on both sides of the
equation, changing the volume does not affect the equilibrium.
Effects of Catalysts:
 Catalyst lowers the activation energy for both forward and reverse reactions, both rates of forward
and reverse reactions are equally affects and so catalyst does not affect equilibrium.
- System just reaches equilibrium in less time.
Heating Cobalt Chloride Hydrate:
CoCl2 (aq) + 6H20 ⇌ CoCl2 ∙ 6H2O (l)
Blue (reactants)

Purple (products)
An exothermic system, LCP that by increasing temperature will cause a shift to the left (dehydrated
reactants)
Equilibrium of Nitrogen and dinitrogen Tetroxide:
2NO2 (g) ⇌ N2O4 (g)
Brown
pg. 6
colourless
∆H= - 57.20 kJ.mol-1
HSC Chemistry Notes

Yr 12 Chemistry
By Tayyab Awais
23/02/2022
An equilibrium between nitrogen dioxide and dinitrogen tetroxide, an exothermic reaction.
Factor
Colour of gas mixture
Dark brown
Which gas is presented
in greater concentration
NO2
Which way does the
equilibrium move
Right
Initially ( … °C temp.
and pressure)
After heating (…°C)
After cooling (…°C)
After increasing
pressure
After decreasing
pressure
Dark brown
Lighter brown
Light brown
NO2
N2O4
N2O4
Left
Right
Right
Darker brown
NO2
Left
Iron (III) thiocyanate and varying concentrations of Ions:
Fe3+(aq) + SCN-1(aq) ⇌ FeSCN2+(aq)
Yellow or colourless (reactants)
Concentration Added
Colour of mixture
Initially
Iron (III) chloride
Ammonium thiocyanate
Calcium fluoride
Yellow
Scarlet Red
Yellow
Colourless
Deep blood red
Which way did equilibrium
move
Nowhere
Right
Right
Left
Equilibrium and Collision Theory:
Le Chatelier’s principle can also be explained using collision theory.
Concentration:
 When adding extra concentration of reactants, the rate of forward reaction becomes favoured as
there are more frequent collisions due to the increased concentration of the reactants.
 As the concentration of the products rises, there will be more frequent collisions and so rate of
reverse reaction will be favoured. Increase in concentration of reactants as well and rate of forward
reaction will decrease.
Pressure:
 Increase in pressure on the equilibrium and the volume occupied by the gases has become smaller,
gas molecules are closer to each other and collision between molecules become more frequent.
Rate of reaction between greater number of molecules (i.e. forward reaction) becomes greater than
the rate of the reaction between the smaller number of molecules (i.e. reverse reaction).
- Increase in reactants and is favoured and the forward reaction decreases, and new equilibrium is
eventually established.

Pressure changes does not affect equilibrium that are in liquid or solid phases as particles are too
tightly packed for an increase in pressure to have any noticeable effect on volume.
Temperature:
 Increase in temperature, molecules move faster due to the heat and there are more frequent and
more energetic collisions. Large number of molecules now have the necessary energy to overcome
the activation energy barrier and undergo successful collisions.
pg. 7
HSC Chemistry Notes
-
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
At higher temperatures, both forward and reverse reactions are favoured however, because
activation energy for endothermic reactions is greater than the exothermic reaction.
This means there will be a greater amount of molecules that can overcome the activation energy
barrier for the endothermic reaction, thus favouring it than the exothermic reaction.
Catalyst:
 Catalyst lowers the activation energy for both forward and reverse reactions by the same amount
which causes an increase in number of effective collisions and results in an increase in both forward
and reverse reactions

Adding water (dilution of solutions):
 shifts equilibrium in the direction of the most particles as less frequent collisions occur. Reaction is
less dependent on collisions (fewer particles reacting) occurs to a great extent
Adding Inert gas (container volume remains constant):
 No change in the equilibrium position. No change in concentration of the reacting gases, so no
change to the rates of the forward and reverse reactions.
Activation energy and heat affecting equilibrium position:
Activation energy is the energy required to break chemical bonds, and cause a reaction to take place.
Calculating the Equilibrium Constant (Keq):
Equilibrium Expression:
Homogenous reaction: A reaction which occurs in a single
The relationship between quantities of reactants and products at equilibrium
Reaction Quotient:
 Uses the symbol Q
 Is called the reaction quotient or concentration fraction (quotient – a quantity produced by the
division of two numbers) aA + bB ⇌ cC + dD
Q = [C]c[D]d / [A]a[B]b

Q can be calculated for any reaction mixture at any point
Equilibrium Constant:
 Uses the symbol K and is called the equilibrium constant (Keq)
pg. 8
HSC Chemistry Notes


Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Keq is only when system is at equilibrium (Q=K)
A system will have a constant Keq at a set temperature
In general, for chemical reactions at equilibrium:
 Different chemical reactions have different value of Keq.
 The size of Keq indicates the proportions (relative amounts) of reactants and products in the
equilibrium mixture.
 For a particular reaction, Keq is constant for all equilibrium mixtures at a fixed temperature.
Reaction Quotient and Equilibrium Constant:
 Both are temperature dependent
 Only include species for which that the concentration can vary
- In a pure state concentration is constant so is not included
- Solutions (aq) vary in concentration so are included
- Gases vary in concentration so are included
- Solids and pure liquids do not vary in concentration in a heterogeneous system (reactants
and products not in the same phase) and so are assumed to be 1 (and are not included in the
expression)
- In a homogenous system (where all substances are in the same phase), solids and liquids are
included because relative proportions are important
Using Q to determine equilibrium:
Q can be used to determine whether a system is at equilibrium.
When Q = Keq then the system is at equilibrium.
If Q < Keq
 there are less products than reactants than at equilibrium (numerator smaller & denominator
bigger)
 Forward reaction will then be favoured
If Q>Keq
 there are more products and less reactants than at equilibrium (numerator larger and denominator
smaller)
 Reverse reaction will then be favoured
pg. 9
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Size of the Equilibrium Constant:
The magnitude of Keq can tell us whether there are more reactant of products in a system at equilibrium.
Keq close to 1 (0.1 to 10)
 there are significant concentrations of products and reactants present at equilibrium
Large Keq (Keq>103)
 concentration of products is much greater than the concentration of reactants
 reaction goes towards completion
 equilibrium lies to the right (Keq >1)
Small Keq (Keq<10 - 3)
 concentration of reactants is much greater than the concentration of products
 reaction only occurs to a small extent
 equilibrium lies to the left (Keq <1)
Unit for equilibrium constants:
 generally reported without units
 concentration for all species must be in mol L-1
pg. 10
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Dependency of an Equilibrium Constant on the Equation:
The equilibrium constant depends on the equation.



If one equation is the reverse of another, then the equilibrium constant are the inverse (or
reciprocal) of each other
If the coefficients of an equation are doubled, the value of Keq is squared
If the coefficients are halved, the value of Keq is the square root of the original Keq
R.I.C.E. Table:
 Useful when trying to calculate the initial or equilibrium concentration of a given reaction
Reaction (R)
Initial concentration (I)
Change in concentration
(C)
Equilibrium
concentration (E)
aA
+
bB
⇌
cC
Effects of Temperature on value of Keq:

The equilibrium constant provides information about the ratio of products to reactants for a specific
reaction at equilibrium at a specific temperature.

Only changes in temperature will change the value of Keq, and the temperature is always specified
when an equilibrium constant is given.

Keq is not affected by the addition of reactants or products, changes in pressure, or the use of
catalysts.
The effect of a change in temperature on an equilibrium constant depends on whether the reaction is
exothermic or endothermic:
 Increasing the temperature in an exothermic reaction will decrease Keq, as the amount of products
present at equilibrium decreases
 Increasing the temperature in an endothermic reaction will increase Keq, as the amount of products
present at equilibrium increases
pg. 11
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Experimental Keq calculations:
Colourimetry:
Colourimetry is a quantitative technique used to measure the difference in the darkness or lightness of the
colour of a solution.
 Coloured solutions absorb light; hence, more light enters the solution than exits it. The amount of
light absorbed by the solution is called the absorbance. This is related to the concentration of the
solution.
 The greater the concentration, the greater the absorbance.
- The Beer–Lambert law states the quantitative relationship between absorbance and
concentration:
A = εlc
where:
 A is absorbance – it does not have units since it is a log10 of the ratio between the light entering and
light exiting the solution.
 ε is the molar absorptivity. It is a constant for a particular chemical. It is a measure of the amount of
light that a solution containing that chemical absorbs per unit of concentration. The units for molar
absorptivity are L mol−1 cm−1.
 l is the path length of the light through the sample. The path length is measured in cm. In this
investigation, you will be using a cuvette with a diameter of 1 cm (hence, l is 1 cm).
 c is the concentration of the solution. The units for concentration are mol L−1.
Since ε and l are constants during the investigation, the Beer–Lambert law indicates that there is a direct
relationship between absorbance and concentration:
Aαc
Keq for different types of chemical reactions:
The equilibrium constant can be used to describe more generally the two kinds of dissociation
reactions;
 The dissociation of ionic solutions
 Dissociation of acids and bases
Dissociation reaction is one in which a compound breaks up into two or more parts.
Dissociation of Ionic solutions:
When a salt is dissolved in water, the crystal is broken down as water molecules draw off the ions (the ions
are hydrated).
 This continues to occur until the solution becomes saturated.
pg. 12
HSC Chemistry Notes

Yr 12 Chemistry
By Tayyab Awais
23/02/2022
This now also represents an equilibrium as the rate of dissociation of solid from the crystal, is
balanced by the rate of association of the salt (as ions in solution combine to form the solid crystal).
Ionic substances dissolve by dissociation. Ion-dipole attractions
are formed between the ions and water molecules.
Eg. NaCl(s)


⇌ Na+(aq) + Cl-(aq)
ΔH = + ve
There is a dynamic equilibrium with the ions in a
saturated solution.
The equilibrium constant for an equation written in
this way is called the solubility product Ksp.
Since this is a heterogeneous system, the solid is not included
on the equilibrium expression.
Ksp = [Na+] [Cl-]
Dissociation of acids and bases:
Equilibrium constants for acids:
Acids ionise in water releasing H+ ions (usually in the form of H3O+) and an appropriate anion. The most
common types of strong acids are:
HCl(aq)
+
H2O(l)

H3O+(aq)
+
Cl-(aq)
HNO3(aq)
+
H2O(l)

H3O+(aq)
+
NO3-(aq)
H2SO4(aq)
+
2H2O(l)

2H3O+(aq)
+
SO42-(aq)
The equilibria for the above ionisations lies well to the right, to the extent that we can consider these acids
to be completely ionised. Hence the single arrow is used. All of these are strong acids. However not all acids
are strong.
CH3COOH(aq)
H2CO3(aq)
+
H2O(l)
+
⇌
2H2O(l)
H3O+(aq)
⇌
+
2H3O+(aq)
CH3COO-(aq)
+
CO32-(aq)
The two acids above are weak acids. They only partially ionise in water and hence an equilibrium is
established. The acids are weak because of the low [H+] in the solutions. As for any other equilibrium we
can calculate the equilibrium constant.
 In this case it is given the special symbol Ka and is referred to as the acid ionisation constant.
The expression for Ka for the ionisation below:
HA ⇌ H+ + Ais:
[H+] [A-]
pg. 13
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Ka = ————
[HA]

Since [H2O] is redundant, it is not used in the calculation of Ka.

The smaller the Ka value, the lower the [H+] in the solution, the weaker the acid and also varies with
temperature
Equilibrium constants for bases:
 Strong bases include the hydroxides of group 1 and 2 metals, e.g. potassium hydroxide and all strong
bases ionise almost completely in solution, so their Kb would be very high
 Weak bases only partially dissociate in water, they react incompletely with water to form hydroxide
ions. This dissociation reaction for ammonia (typical weak base) is:
NH3(aq) + H2O(l) ⇌ NH4+(aq) + OH-(aq)
The general equation for a base reacting with water is:
B(aq) + H2O(l) ⇌ BH+(aq) + OH-(aq)
Therefore the general expression for the base dissociation constant for a weak base is:
Kb = [BH+] [OH-]
[B]
pg. 14
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
Module 6: Acid/Base Reactions
Properties of Acids and Bases:
Nomenclature and Properties of common inorganic acids/bases:
IUPAC naming make sure of it such as oxyacids and all that
Acids:
Acids: A substance that is capable of donating a hydrogen ion (proton).
Acid properties:
 Sour taste
 Can conduct electricity in solution
 Dissolve in water to form excess H+ ions
 Turn blue litmus paper red
Common uses for acids:
 Sulfuric acid is used in car batteries, fertilisers, plastics, dyes, explosives
 Hydrochloric acid is used to clean metals and bricks
 Nitric acid is used in fertilisers and explosives
Formula
HBr
H2CO3
HF
pg. 15
Common Name
Hydrobromic acid
Carbonic acid
Hydrofluoric acid
23/02/2022
HSC Chemistry Notes
HI
H2S
HNO3
HNO2
H3PO4
H2SO4
HCl
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Hydroiodic acid
Hydrogen sulphide
Nitric acid
Nitrous acid
Phosphoric acid
Sulphuric acid
Hydrochloric acid
Bases:
Base: A substance capable of accepting a hydrogen ion (proton).
Base properties:
 Have bitter taste
 Soapy feel
 Neutralise the effects of acids
 Can conduct electricity in solution if base is soluble (alkali)
 Turns red litmus blue

Bases are used in household cleaners, soaps, toothpaste and detergents.
Bases
Common Name
Sodium hydroxide
Ammonia
Ammonium Hydroxide
Calcium Hydroxide
Magnesium hydroxide
Sodium carbonate
Potassium hydroxide
Lithium hydroxide
NaOH
NH3
NH4OH
Ca(OH)2
Mg(OH)2
Na2CO3
KOH
LiOH
Use of indicators as illustrators:
Indicator: A substance that changes colour when it comes into contact with a solution with a difference pH.
`
How indicators work:
Most indicators are weak acids or bases.
Hind(aq) ⇌ H+(aq) + Ind-(aq)
Molecule (Colour 1) ⇌ Hydrogen Ion + Anion (colour 2)

Changes in [H+] will shift the equilibrium
I.
For low PH (High [H+])  Equilibrium will lie towards LHS and observed colour will be colour
1
II.
For High pH (low [H+])  Equilibrium will lie towards RHS and observed colour will be colour
2
Indicator
Methyl orange
Bromothymol blue
Phenolphthalein
pg. 16
Colour at lower pH
Red
Yellow
Colourless
Colour at high pH
Yellow
Blue
Pink
pH of colour change
range
3.1 – 4.4
6.0 – 7.6
8.3 – 10.0
HSC Chemistry Notes
Yr 12 Chemistry
Methyl red
Litmus
Phenol red

Red
Red
Yellow
By Tayyab Awais
Yellow
Blue
Red
23/02/2022
4.8 – 6.0
4.5 – 8.3
6.8 – 8.4
Universal indicator: A mixture of different indicators that
displayed a range of colours over the pH range of 1-14 when
added to solution.
Limitations of Indicators:
 Provide only an approximate pH
 Cannot identify the strength of the acid or base
 Destroys/contaminates solutions
Uses of indicators:
 They are used for testing: soil, swimming pools, aquariums and
the end point of quantitative acid-base reactions.
Products of acid reactions:
Acid and Bases:
When an acid reacts with a base, they form salt and water compounds
(also called neutralisation reaction).
 If the right amount of acid and base are reacted, the resulting solution will be neutral.
Neutralisation reaction written as; Acid + Base  Salt + Water
E.g.


NaOH(aq) + HCl(aq)  H2O(l) + NaCl(aq)
2HCl(aq) + Ba(OH)2(aq)  2H2O(l) + BaCl2(s)
Acid + Metal oxide/hydroxide:
Acid + Metal Oxide/Hydroxide  Salt + Water
E.g. 2HCl(aq) +MgO(s)  MgCl2(aq) + H2O(l)
 Ammonia is a separate case.
Acid and carbonate:
When an acid and carbonate react, they produce salt, water and carbon dioxide.
Acid + Carbonate  Salt + Carbon dioxide + Water
E.g.


2HCl(aq) + Na2CO3(aq)  2NaCl(aq) + H2O(l) + CO2(aq)
CuCO3(aq) + H2SO4(aq)  CuSO4(aq) + H2O(l) + CO2(g)
Acid and metal:
When an acid and metal react, they produce a salt and hydrogen gas according to the equation;
Acid + Metal  Salt + Hydrogen gas
pg. 17
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
E.g.


H2SO4(aq) + Mg(s)  MgSO4(s) + H2(g)
2HCl(aq) + Mg(s)  MgCl2(aq) + H2(g)
Everyday applications of neutralisation reactions:

Industrial purposes: Industrial treatment of water uses several neutralisation stages.
- Water is made alkaline for the cleaning process, then completely neutralised before it is
consumed.

Human body: In stomach, acids are used to break apart the food fer nutrients. When those nutrients
move into the intestines, an alkaline environment is preferred. Thus, the pancreas produces a basic
substance to neutralise the stomach acid.

Antacids (Medical): Condition called acid reflux causes acid from stomach to rise into oesophagus
causing burning sensation called heartburn. To neutralise the acid, people take antacids containing
base magnesium hydroxide or sodium bicarbonate.
Enthalpy of neutralisation reactions:

The enthalpy of neutralisation is the thermal energy change in the reaction when an acid and a base
reaction react to form 1 mol of water under standard conditions.
H+(aq) + OH-(aq)  H2O(l)

∆H(neut) = -57kJmol-1 at 25⁰C.
Reaction is exothermic because it results in the formation of a new covalent bond between the
hydrogen and oxygen as water molecules form.
Measuring energy released by a neutralisation reaction:
q = mc∆T , where;
 q = energy
 m = mass (g)
 c = specific heat capacity
 ∆T = change in temperature
Change in Enthalpy formula; ∆H =
−𝑞
𝑛
Changes in definitions and models of acids and bases:
Acids and bases were originally differentiated based on their basic properties such as taste and texture. Later
on, scientists began defining acids based on their chemical properties.
Year
Scientist(s)
1884
Svante Arrhenius
pg. 18
Acid definition

Acids are
substances that
produce
hydrogen ions
(H+) when in
water.
Base definition

Bases were
substances
that when
ionised in
water, would
produce
Limitations


Bases such as
ammonia and
sodium carbonate
do not contain a
hydroxide group.
Only applies to
aqueous solutions
HSC Chemistry Notes
1923
Yr 12 Chemistry

Acids are strong
if they ionised
completely in
water and weak
if ionised only
slightly
Johannes Brönsted

Acids/Bases are
defined by their role in
a reaction.
 An acid-base
reaction is a
protontransfer
process.

Acids are
proton doners.
An acid must
contain H in its
formula.
By Tayyab Awais
23/02/2022
hydroxide ions
(OH-).


Bases are
proton
acceptors.
A base must
contain an
atom with a
lone pair of
electrons to
bind to the H+
ion.
and didn’t explain
neutralisation
reaction in the
gas phase.


Couldn’t explain
the reactions
between acidic
oxides and basic
oxides.
Unable to explain
why some
molecules (e.g.
BF2) is an
acid/base as it
does not have any
H+
Amphiprotic substances:
Amphiprotic: The ability of a substance to act as both an acid and a base.

Water is a common amphiprotic substance.
- When acids react with water, hydronium (H3O+) ions are produced. When bases react with
water, hydroxide (OH−) ions are produced.


HCl(g) + H2O(l) → Cl- (aq) + H3O+(aq)
NH3(aq) + H2O(l)  NH4+(aq) + OH-(aq)
E.g.
Monoprotic Acids:
Monoprotic acids can only donate 1 proton.
e.g. HF + H2O  F- + H3O+
Diprotic Acids:
Can donate 2 protons.
e.g.


Step 1: H2SO4 + H2O  H2SO4- + H3O+
Step 2: HSO4 + H2O  SO4-2 + H3O+
Triprotic Acids:
Can donate 3 protons.
e.g.



pg. 19
Step 1; H3PO4 + H2O  H2PO4- + H3O+
Step 2; H2PO4- + H2O  H2PO4-2 + H3O+
Step 3; H2PO4-2 + H2O  PO4-3 + H3O+
HSC Chemistry Notes

Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Polyprotic acids are acids that can donate 2 or more protons.
Using Brønsted–Lowry Theory:
pH of a range of acids and bases:


Stronger acids have a low pH
Stronger bases have a high pH
pH and pOH:
The pH and pOH scales have been developed to measure the acidity or basicity of substances/solutions.
pH scale:
 Is a measurement of the acidity of solution based on the number of hydronium ions [H+] present.
 The term pH stands for hydrogen power. It
pH = -log[H+]

or
[H+] = 10-pH
A change in pH of one unit corresponds to a tenfold change in [H3O+].
- E.g. A solution with a pH of 2 has 10 times the concentration of hydronium ions as one with
a pH of 3
pOH scale:
 Is a measure of the basicity of solutions based on the oxide ions [OH-] concentration present.
pOH = -log[OH-]


or
[OH-] = 10-pOH
pH + pOH = 14
[H+] x [OH-] = 10-14
pH and pOH of acidic and basic solutions:
Question: Calculate the pH and pOH of a substance in which the concentration of H3O+ is 0.14 M (2 d.p.)
pg. 20
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
pH = -log[H3O+] = - log0.14 = 0.85
pH + pOH = 14 0.85 + pOH = 14
∴ pOH = 14- 0.85 = 13.15
Uses of pH to indicate the difference between the strength of acids and bases:
Ionic equations to represent the dissociation of acids and bases in water, conjugate
acid/base pairs in solution and amphiprotic nature of some salts:
Dissociation of acids and bases in water:
Acid:
HA(aq) + H2O(l) ⇌ H3O+(aq) + A-(aq)
∴ proton donor
 Hydronium ion (H3O+) produced when a hydrogen ion (H+) attaches to a water molecule.

E.g. HCl + H2O  Cl- + H3O+
Base:
B(aq) + H2O(l) ⇌ BH+(aq) + OH-(aq)
∴ proton acceptor

E.g. NaOH + H2O  NaOH2 + OH-

H3O+(aq) ⇌ H2O(l) + H+(aq) (Called ionisation reactions)
Acids + Bases and their Conjugates:
A conjugate acid/base pairs are two molecules or ions that differ by one proton (H+).
 When an acid donates a proton, one of the products will be a base.
 When a base donates a proton, one of the products will be an acid.
Acid and its conjugate:
Acid  proton + base
 E.g. NH4(aq)+  H+ + NH3(aq)


The stronger the acid, the weaker the conjugate base
The weaker the acid, the stronger the conjugate base
Base and its conjugate:
Base + proton  acid
 E.g. F + H+  HF


The stronger the base, the weaker the conjugate acid
The weaker the base, the stronger the conjugate base

Overall:
-
Acid + Base ⇌ conjugate base + conjugate acid
Amphiprotic nature of salts:
pg. 21
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Amphiprotic substance are those that can act both as both a proton donor and acceptor, depending on the
substance it has been introduced to.

Water (H2O):
- As a proton donor: Cl- + H2O(l)  HCl(aq) + OH- As a proton acceptor: NH4+(aq) + H2O(l)  NH3(aq) H3O+

Hydrogen Carbonate (HCO3-):
- As a proton donor: HCO3-  CO2-3 + H+
- As a proton acceptor: HCO3- + H+  H2CO3 (aq)

Dihydrogen phosphate (H2PO4-):
- As a proton donor: H2PO4-  HPO42- As a proton acceptor: H2PO4 + H+  H3PO4 (aq)
Models/animations to show differences between strong, weak, concentrated and dilute
acids and bases:
Strong and weak acids (Concentrated and dilute acids):
Acid strengths are determined through measuring the extent to which they dissociate in a solution
Strong Acid:
Strong acids dissociate completely in solution (total ionisation)
 Represented with one sided arrow ()
- E.g. HCl  H+ + Cl
Examples of strong acids; HCl, H2SO4, HNO3 , HClO4, HClO3
Weak Acid:
Weak acids dissociate partially in solution, forming some ions and some original acid particles
 Represented with equilibrium arrow (⇌)

Examples of weak acids; H2SO3, CH3COOH, HNO2, H2CO3, H3PO4
Modelling Strong and weak acids (Concentrated and dilute):
pg. 22
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Module 7: Organic Chemistry
Nomenclature
Nomenclature: Is a system of names or terms, or the rules for forming these terms.
IUPAC: International Union of Pure and Applied Chemistry is the universally recognised authority on
chemical nomenclature and terminology.
Naming Organic Compounds:
All life on Earth is based on carbon compounds, operating within an aqueous (water) environment.
 Organic chemistry is the study of compounds on carbon, called organic compounds
 Carbon contains six electrons (2,4 configuration), meaning it can form four covalent bonds
 Carbon is a non-metallic chemical element found in group 14 of the periodic table
Bonding in Carbon Compounds:
pg. 23
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Representing Organic Molecules:
Molecular Formulae: indicate the number and type of atoms of each element present in a molecule,
however they do not indicate how the atoms are arranged. E.g., C2H6O
Structural Formulae: show the spatial location of atoms relative to one another as well as the number and
location of covalent bonds, following the VSEPR theory.
Condensed Structural Formula: show the atoms that are connected to each carbon atom but do not show
the bonds.
Shown down below
pg. 24
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Functional Groups: A specific group of atoms, within a molecule, that is responsible for the chemical
reactions of that molecule. Functional groups are attached to the hydrocarbon ‘backbone’ of organic
molecules.
Hydrocarbons: Hydrocarbons are organic compounds containing only carbon and hydrogen atoms
Homologous Series:
Homologous Series: Each family of hydrocarbons. Homologous means that all members of a series have
something in common – they share a general formula and a special feature or functional group.
 Similar structures
 Similar chemical properties
 The same general formula
 A pattern to their physical properties
Saturated vs Unsaturated Organic Compounds:
Saturated: A saturated organic compound only contains single bonds between carbon atoms
Unsaturated: An unsaturated organic compound are hydrocarbons that have double or triple covalent bonds
between adjacent carbon atoms
Naming Carbon Atoms Rule:
Number of
Carbon Atoms
1
2
3
4
5
6
7
pg. 25
Prefix
MethEthPropButPentHexHept-
HSC Chemistry Notes
8
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Oct-
Naming Organic Compounds:
Alkanes:
Carbon compounds containing single bonds
 Alkanes are saturated
ALKANE Formula: CnH2n + 2


Stem; Length of the carbon chain
Suffix; Family of alkane compounds end in ‘-ane’.
Alkenes:
Hydrocarbons with a double bond between a pair of carbon atoms
 Unsaturated hydrocarbons- reactive double bonds
ALKENE Formula: CnH2n


where n>1
Stem; Number of carbon atoms
Suffix- Family compound of alkenes ends in ‘-ene’
Naming Alkenes:
 Identify the longest continuous chain of carbon atoms
 Location of double bond shown by putting in front of the name the number of the carbon atom at
which the double bond starts
 Numbering begins from the end that minimises the number for the double bond
pg. 26
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Alkynes:
Hydrocarbons with at least one CΞC triple bond
 Unsaturated hydrocarbons- Reactive triple bond
ALKYNE Formula: CnH2n-2
Where n>1


Stem; Length of the carbon chain
Suffix: Family of alkynes compounds end in ‘-yne’.

Chain numbered from the end that gives the position of the triple bond its lowest number
pg. 27
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Alkyl Groups:
An alkyl group is an alkane molecule with one hydrogen atom missing that can be part of another molecule
 These are called branched chain hydrocarbons (or side chains)
Alkyl group examples:
 Methyl; ‘-CH3’

Ethyl; ‘- CH2CH3’

Propyl; ‘-CH2CH2CH3’

Butyl; ‘- CH2CH2CH2CH3’
RULES for naming hydrocarbons with alkyl groups:
1. Find the longest carbon chain and select the appropriate name as per previous naming. (Longest
chain doesn’t have to be straight) (Do not include side chains in carbon count).
2. Name the side chains and list them in alphabetical order.
3. Number the longest chain so as to minimise numbers that match positions of alkyl groups.
Alcohols:
Alcohols are organic compounds containing the hydroxyl functional group (-OH).
 Attached to a saturated carbon atom
 Names of all alcohols have the suffix ‘-ol’
 General formula for alcohols is CnH2n+1OH
Naming Alcohols:
pg. 28
HSC Chemistry Notes


Yr 12 Chemistry
By Tayyab Awais
23/02/2022
For alcohols, replace the -e of the hydrocarbon with the -ol at the end of the hydrocarbon name
Indicate position of the hydroxyl group with a number before the -ol ending
Types of alcohols:
Alcohols are classified according to how many alkyl groups are attached to the carbon bonded to the
hydroxyl group

pg. 29
Three different types of alcohols are
- Primary: The -OH group is attached to one carbon only, the end (terminating) carbon
- Secondary: The -OH group is attached to one carbon which is also bonded to two other carbons
- Tertiary: The -OH group is attached to one carbon that is also bonded to three other carbons
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Aldehydes:
 Apart of the carbonyl functional group and is always at the terminal (end) of the hydrocarbon chain
 Called ‘Alkanals’ with the general structure of;

R can be denoted as a hydrogen or a hydrocarbon group


Aldehydes are written as ‘-CHO’ at the end of the condensed structural formula
Suffix: ‘-al’
General formula for aldehydes:
pg. 30
CnH2nO
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Carbonyl Functional group: A functional group composed of carbon atom double-bonded to an oxygen
atom: C=O
Ketones:
Apart of the carbonyl functional group (C=O) that is within the carbon chain and is never on the terminal of
the carbon chain.
 Called alkanones with the general structure:



Both R1 and R2 stand for the hydrocarbon group
Ketones are written as ‘-CO-‘ in a condensed structural formula
Suffix: ‘-one’
General formula for ketones: CnH2nO
pg. 31
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Carboxylic Acids:
Carboxylic acids comprise a homologous series of molecules that contain the carboxyl functional group with
the structure
 Made up of a carbonyl group attached to a hydroxyl group

The carboxyl functional group is represented in a condensed structural formula as ‘-COOH’ and
must be on the terminal carbon

Because of the presence of the C=O attached to the same carbon, the –OH bond in the hydroxyl
group becomes more polarised and will ionise in water forming hydronium ions.
- This is why they are called acids. However, they are weak acids because the degree of ionisation
is typically less than 1% or less.

Suffix: ‘-oic acid’
General formula for carboxylic acids is: CnH2n+1COOH.
pg. 32
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Naming Carboxylic Acids:
 Same rules as for alkanes except suffix ‘-e’ changes to ‘-oic acid’
 The carbon atom double bonded to the oxygen is always counted as carbon 1
Amines:
A homologous series that contains the amino functional group (-NH2)
 Amino functional group: Consisting of one nitrogen atom covalently bonded to two hydrogen atoms
 Ends with the suffix ‘-amine’

Amines are widely found in nature as amino acids which are the building blocks of proteins.
Naming amines:
 For amines, replace the -e of the hydrocarbon with the -amine at the end of the hydrocarbon name
 Indicate the position of the amino group with a number before the -amine ending
pg. 33
HSC Chemistry Notes

Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Chain alkyl groups that are attached to the N-substituents are written as ‘N-alkyl’ or ‘N, N-dialkyl’
- E.g. N-methyl, N-propyl, etc.
Do we need to know primary, secondary and tertiary amines?
Amides:
Amides are derivates of carboxylic acids and are formed when the -OH group of the acid is replaced by an
amine (-NH2)

pg. 34
The amide functional group is represented in a condensed structural formula as ‘-CONH’
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Halogenated Organic Compounds:
Haloalkanes: A molecule derived from an alkane, in which one or more hydrogen atoms are replaced with
halogen atoms
Halogen: An element in Group 17 of the periodic table; Halogens have seven valence electrons so they can
form a single covalent bond with carbon atoms
Halo functional Group: A functional group that consists of halogen atoms bonded to the carbon chain. The
halo functional groups are named Fluro-, chloro-, bromo- and iodo-.
Halogen
Fluorine
Chlorine
Bromine
Iodine
Naming Haloalkanes:
pg. 35
Functional Group
Name
FluroChloroBromo
Iodo-
HSC Chemistry Notes
Yr 12 Chemistry
1. Place the name of the halo group at the start
2. If position isomers present, use numbers to indicate
which carbon halo group is attached to
3. Number carbons of the parent chain beginning at end
closest to halo group
4. If there is more than one of the same type of halogen,
use the prefix “di”, “tri” or “tetra” to show numbers
5. If more than one halo group present, list in alphabetical
order
Overview of IUPAC organic nomenclature:
Summary of IUPAC rules:
Naming Conventions:
pg. 36
By Tayyab Awais
23/02/2022
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
o
Organic molecules with
more than
two functional groups:
 If two functional groups are the same, a multiple (di-, tri, etc.) is used
 If different, you will need to look at which function group has the highest priority
- Highest priority functional group is assigned the lowest possible number and the suffix for the
functional group is used in the name
- The lower priority functional group is indicated by a prefix or alternative name
pg. 37
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Structural Isomers:
Structural Isomers: Structural isomers are compounds that have the same molecular formula but different
structural formulae
 Isomers can have different physical and chemical properties
 Different Types of structural isomers include;
- Chain isomers
- Position isomers
- Functional group isomers
Chain Isomers: An isomer of an organic molecule resulting from a branching of the hydrocarbon chain
 They differ based on the carbon chain that forms the backbone
Position Isomers: An isomer that arises from having the functional group on a different location on the
carbon chain
 They differ based on the based on the location of the functional group and can also occur when
multiple bonds are in different locations (e.g., double or triple bonds etc.)
pg. 38
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Functional group Isomers: An isomer that arises from having different functional groups but same molecular
formula
(EXTRA) Geometric Isomers: each of two or more chemical compounds having the same molecular formula
but a different geometric arrangement;
Hydrocarbons
●
construct models, identify the functional group, and write structural and molecular formulae for
homologous series of organic chemical compounds, up to C8 (ACSCH035) :
– alkanes
– alkenes
– alkynes
Properties and structures of organic chemical compounds:
Physical and chemical properties of hydrocarbons are heavily determined by the intermolecular forces and
the shape of the molecules
 Hydrocarbons generally have a low boiling and melting points as dispersion forces are weak, so easy
to separate molecules
 Are also usually non-conductors of electricity
pg. 39
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Intermolecular forces: attractive forces between molecules
Intramolecular forces: covalent bonds joining atoms together in the molecule

Alkanes and alkenes contain three types of bonds within the molecules which are all non-polar
covalent:
- Single C-C bonds
- Double C=C bonds
- C-H bonds

Branched molecules have weaker dispersion forces between the molecules because they do not
pack as closely, so their BP are low than straight—chain hydrocarbons
Physical properties of Alkanes:
 Reactivity of alkanes is quite low, however the smaller the alkane is, the more reactive it will be
- E.g. Methane is more reactive than octane

Boiling points for alkanes:
- Because alkanes are non-polar, meaning the only intermolecular forces are weak dispersion
forces between them
- As the length of the carbon chain increases, the overall dispersion forces increase between the
molecules because more electrons are available to create a stronger temporary dipole force
- Thus, for alkanes, the boiling point is directly proportional to size of alkane molecule

Melting points of alkanes:
- Melting points of alkanes generally follow the same trend as boiling points, with a few
exceptions
- Melting points of straight-chain hydrocarbons increase as the number of carbon atoms increase
but is dependent whether there are odd or even number of carbons
 If even, carbon atoms pack more efficiently in the solid state, meaning more energy is
required to melt the compound (high MP)
 If odd, then the compound will have lower MP compared to even
Physical Properties of alkenes and alkynes:
Boiling point:
 Alkenes and alkynes are non-polar so the forces of attraction between them are only weak
dispersion forces, just like alkanes
 Members of these homologous series have relatively low BP, similar to their corresponding alkane
pg. 40
HSC Chemistry Notes

Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Boiling points for alkenes and alkynes also increase with the molecular size as the strength between
molecules increases
Melting Point:
 Alkenes and alkynes melting points follow a similar pattern to an alkane’s melting points, carbon
chain increase then melting point increases.

For alkynes, the position of the triple bond can greatly affect melting points as the shape of the
molecule changes
- E.g. Isomers such as but-1-yne and but-2-yne have melting points at -122 °C and -24 °C, a
difference of nearly 100 °C
Physical Properties of Haloalkanes:
Boiling point:
 Haloalkanes are polar as halogens are very electronegative
 The polarity (presence) of haloalkanes allows for dipole-dipole intermolecular forces to also occur.
With dipole-dipole forces stronger than dispersion forces, boiling points of haloalkanes are generally
higher than their corresponding hydrocarbon
Melting Point:
 Melting point for haloalkanes are higher compared to hydrocarbons just like boiling point due to the
polar halogen-carbon bonds present in the compounds
Solubility in Water:
Alkanes, alkenes and alkynes are insoluble in water as they are non-polar. This is because water molecules
are polar and are held by strong hydrogen bonds meaning only polar substance can dissolve with water
(mix).
 Weaker dispersion forces between molecules means that they don’t pack as closely as water
molecules that have strong hydrogen bonds
Haloalkanes are slightly more soluble than hydrocarbons in water due to the presence of polar halogencarbon bond meaning they are relatively insoluble as the dipole-dipole interactions are very small
 The longer the carbon chain is, the less soluble it is as the influence or effect of the halogen-carbon
bond decreases
pg. 41
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Shape of molecules:

Molecular shape also affects the strength of dispersion forces and by extension BP and MP
Conventions for reading shapes of molecules are that
 Dotted bonds indicate that the bond goes ‘backwards’ (i.e. into the page)
 Wedged bonds indicate that the bond goes ‘forwards’ (i.e. out of the page)
geometrical
arrangement Bond Type
of atoms
present
Structure
bond
angles
example
ethane
tetrahedral
single
109.5°
Trigonal
planar
double
120°
ethene
linear
triple
180°
ethyne
Safety Handling of Organic substances:


Alkanes – C1 to C8 extremely flammable and toxic
Low boiling point of alkanes gives rise to high volatility of liquid alkanes – if container left open liquid
can evaporate quickly and form a flammable or explosive mixture with air.
Precautions:
1. Use well maintained cylinders and fittings for gaseous hydrocarbons
pg. 42
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
- Methane and ethane (and natural gas)
2. Add odours for detection of leaks
- natural gas and LPG given smell so they can be detected
3. Use sturdy containers for liquids
- store in metal rather than plastic with narrow mouth
4. Minimise quantities
5. Warning signs
Environmental, Economic and Sociocultural implications of hydrocarbons from the
Earth:


Organic substances are all around us both in nature and produced synthetically
Many man-made products we use every day are derived from organic compounds
- Flavorings
- Colorings
- Pesticides
- Polymers
- Plastics
- Dyes
- Medicines

While the use of hydrocarbons has provided society with many benefits, there are also various
negative consequences related to use of hydrocarbons
- Burning of fossil fuels results in smog, acid rain, the destruction of natural ecosystems and
climate change
pg. 43
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Products of reactions involving hydrocarbons


Alkanes undergo substitutions and combustion reactions
Alkenes and alkynes undergo addition and combustion reactions
Addition Reaction:
Alkenes and alkynes are highly reactive due to the presence of the double bond or triple bonds, meaning
their bonds are weaker and easier to break.
Many substances will react with alkenes by opening their double bonds to form two single bonds, a reaction
called addition reaction.
 No atoms are left over in the addition reaction
 Substances such as hydrogen (H2), water (H2O), hydrogen halides (HX) or halogens (X2) are reacted
with an alkene or alkyne and all of the atoms of the molecule are added to the alkene/alkyne
structure
Addition of Hydrogen:
When hydrogen gas (H2) is added, unsaturated hydrocarbons will react to incorporate the additional
hydrogen atoms into the molecule.
 This process is called ‘hydrogenation’.
 Requires a metal catalyst such as e.g., Ni, Pt, Pd, Rh.
 Alkynes are converted to alkenes. Alkenes are converted to alkanes
pg. 44
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
Addition of Halogens:
Halogens (X2) react with the unsaturated hydrocarbons due, and this type of reactions is called
‘halogenation’
 Due to the reactivity of the halogens, no catalyst is required

pg. 45
Types of halogens
- Fluorine
- Chlorine
- Bromine
- Iodine
23/02/2022
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Addition of Hydrogen Halides:
Hydrogen halides (HX) are molecules with a hydrogen atom and a halogen atom like F, Cl, Br, I.
 Reaction called ‘halohydrogenation’
Addition of Water:
Water will only react with unsaturated hydrocarbons under acidic conditions, meaning a dilute sulfuric acid
catalyst is required.
 This reaction is called hydration


pg. 46
When water is added to an alkene, one of the hydrogens from the water molecules attaches to one
carbon and the remaining, -OH attached to the other carbon.
Addition of water to an alkyne will produce a ketone and is catalysed by Mercury (II) compounds and
sulfuric acid
- Exception is that hydration of ethyne that produce ethanal since a ketone cannot form with only
two carbons in the main chain
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Important notes on addition reactions:
1. When a symmetrical reagent (e.g., H2 or Cl2) is added, the product of the reaction has the same
group added to each carbon.
2. When an asymmetrical reagent (e.g., H2O or HBr) is added to a symmetrical alkene there is only one
possible product.
However:
3. When an asymmetrical reagent (e.g., H2O or HBr) is added to an asymmetrical alkene, there are two
possible products. In reality, one product dominates.

pg. 47
Markovnikov’s rule states that the hydrogen atom will predominantly add across the double bond to
the carbon that already has the greatest number of hydrogen atoms, creating a major and minor
product.
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Substitution Reaction:
Substitution reaction occurs when an atom or a functional group in a molecule is replaced of ‘substituted’ by
another atom or group. Alkanes are saturated hydrocarbons and undergo substitution reaction with
halogens to produce haloalkanes.
 This reaction must be initiated by ultraviolet (UV) light as saturated hydrocarbons are unreactive
pg. 48
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Combustion Reaction:


Alkanes are very good fuels and burn easily in air in an exothermic reaction
Alkanes which burn in excess oxygen go through complete combustion
•
Alkenes also burn in an excess of oxygen to from carbon dioxide and water
Alcohols
Properties and Structural Formulae for types of alcohols:
Alcohols are polar covalent bonds due to the presence of the hydroxide group

The most common alcohol is ethanol – a colourless liquid with a faint, sharp odour. It is the key
ingredient in alcoholic beverages. Ethanol is a primary alcohol, and it looks like this.
Properties and structural formulae for primary, secondary, and tertiary alcohols is listed above on page 6
under nomenclature subtopic.
Properties of Alcohols:
The polar covalent bond in the -OH group creates a charged dipole and strong hydrogen bonding exits
between the molecules
pg. 49
HSC Chemistry Notes

Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Alkanols are inflammable, and can be used as fuels, although their energy content is not as high as
alkanes
Boiling Points:
Alcohols have considerably higher boiling points than corresponding alkanes due to the presence of
hydrogen bonds between alcohols molecules.
 Boiling point of methanol is more than 200 degrees higher than the boiling point of methane
NOTE: Graph not totally accurate with figures of boiling points but general trend is correct

Effect of carbon chain length on boiling point: As molar mass of molecules increases; the boiling
points increase due to the increasing dispersion forces.
Two factors to consider:
 Similar to alkanes, branching reduces the strength of dispersion forces
 The position of the hydroxyl group within the molecule affects the strength of hydrogen bonding.
- The more ‘crowded’ the hydroxyl group is, the weaker the hydrogen bonding resulting in lower
boiling points
- Due to this, boiling points of these alcohols decrease in the sequence from primary, secondary
then the tertiary alcohol
Solubility in Water:
pg. 50
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Alcohols with short hydrocarbon chains dissolve (1-3 carbon atoms long) (are soluble) in water due to
alcohols being very polar
 Hydrogen bonds form between the partially positive hydrogen atom of the hydroxyl group and the
lone-pair electrons of an adjacent water molecule
 There is also an also attraction between the partially positive hydrogen within the water molecules
and the lone-pair electrons on the alcohol molecules

Effect of the chain length on solubility: The solubility of alcohols in water decreases with the
increasing length of the hydrocarbon chain as the non-polar nature of the molecule increases,
reducing solubility.
- Smaller alkanols can form hydrogen bonds with water bonds, allowing it to be miscible.
-

“Only dispersion forces occur between hydrocarbon chain and water molecules, which are not
as strong as hydrogen bonds.”
Alkanols are excellent solvents as they can dissolve many water-soluble (polar) solutes, but also
many non-polar substances which do not dissolve well in water.
- Main reason why ethanol is widely used in industries to dissolve reagents, pharmaceuticals and
food chemicals.
Equations and Reactions of Alcohols:
Combustion:
Alcohols (alkanols) easily undergo combustion reactions with oxygen. In a complete combustion, carbon
dioxide and water is formed as long as there is enough oxygen supplied. In a limited oxygen reaction, carbon
monoxide (CO) and soot (Cs) may also form.
 As the chain length increases, there is a noticeable tendency towards incomplete combustions
 Petrol contains 10% of ethanol because it combusts easily and completely
Ethanol + Oxygen  Water + Carbon dioxide
Dehydration:
Dehydration is the removal of water from the chemical structure, specifically from the alcohol functional
group and an adjacent carbon’s hydrogen.
 Concentrated phosphoric (H3PO4) or sulfuric acid (H2SO4) are used as dehydrating agents.
pg. 51
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Substitution of HX:
Substitution (removal) of one functional group and replacement with another group. Removal of -OH
hydroxyl group forming water and the halogen atom replacing the -OH group.
 An acid catalyst is required
 In reactions with hydrogen halides, tertiary alcohols are most reactive and will have very fast
reactions with HX.
- Secondary alcohols are less reactive, with primary alcohols even less reactive. Methanol is
particularly difficult to react with HX.
 The hydrogen halide reactivity in this reaction increases as you go down the halogen group.
- HF is very difficult to react, while HI is the most reactive of the HX compounds.
Oxidation:
A reaction in which a chemical substance loses electrons.
 Mild oxidants that can be used to oxidise alcohols (alkanols) include Chromium trioxide (CrO3).
 Strong oxidants include acidified Potassium permanganate (KMnO4) and Potassium dichromate
(K₂Cr₂O₇)
Oxidation of primary alcohols:
Using a mild oxidant (H+/ CrO3), oxidising a primary alcohol (alkanol) will form an aldehyde (-CHO) functional
group. If a strong oxidant such as (H+/KMnO4), then the alkanal will oxidise to produce an alkanoic acid
(carboxylic acid).
pg. 52
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Oxidation of Secondary Alcohols:
Oxidation of secondary alcohols results in the formation of ketones (alkanones) using a mild or strong
oxidising agent.
 The alkanones cannot be further oxidised. Alkanones contain the carbonyl functional group (C=O).
Oxidation of Tertiary alcohols:
Tertiary alcohols are resistant to reactions with an oxidising agent, meaning tertiary alcohols cannot be
oxidised.
 This is because the carbon atom that carries the OH group does not have a hydrogen atom attached
but is instead bonded to other carbon atoms, meaning No reaction as no C-H bond to break to result
in increase of C-O bonds
Production of Alcohols:
Alcohols are prepared in various ways depending on the purpose for the alcohol and are prepared through
 Substitution reactions of haloalkanes
 Fermentation of carbohydrates
For alcohols in beverages and biofuels, fermentation is used while industrial alcohols are produced by
substitutions of haloalkanes.
Substitution reactions of halogenated organic compounds:
A substitution reaction can occur in a haloalkane where there is a highly polar bond between the carbon and
the halogen. The carbon which carries a partially positive charge can be ‘attacked’ by a negatively charged
species.
pg. 53
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
This can occur with the hydroxide ion from aqueous sodium hydroxide. An alcohol will be formed because
the halogen will be replaced with the hydroxyl group in the substitution reaction.
It is also possible for haloalkanes to undergo substitution reactions with water to form alcohols. This reaction
occurs much more slowly and requires a catalyst.

Aqueous solutions of strong bases such as sodium hydroxide, NaOH (aq), or potassium hydroxide,
KOH(aq), are good sources of hydroxide ions for the reaction.
Fermentation of Carbohydrates:
Fermentation is the simple process of converting simple sugars like glucose into ethanol in an anerobic
environment to make fuels or alcoholic beverages.
 Many different alcohols can be made but ethanol is the most common one
Conditions for fermentation:
 Temperature – 15-30 degrees Celsius, too low no reaction, too high enzyme denatured
 Absence of Oxygen – ethanol will be oxidized in the presence of oxygen
 Catalyst- Yeast:
- Glucose passes through the cell walls of the yeast where it is then used by the organism to
produce energy through normal metabolic pathways. The yeast will then produce ethanol as a
by-product of these processes and is excreted out the yeast along with carbon dioxide.
pg. 54
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Fossil fuels and biofuels:
Fuels contain chemical energy that is relatively easily released as a useful source of energy. Energy sources
can
be classified in terms of their renewability.
 Non-renewable resources are resources that are used at a rate faster than they can be replaced.
Examples are fossil fuels, which include coal, crude oil, petroleum gas and coal seam gas.
 Renewable resources are resources that can be continually replaced, or which do not involve the
consumption of the resource. Examples are wind, water, tides, biomass, and solar energy. Biofuels,
such as bioethanol, biogas and biodiesel, are fuels obtained from living systems.
Energy
Output
Cost
Transport
Source
Renewable
or Nonrenewable
Table below not necessary to revise it
Petrol
LPG
pg. 55
Natural Gas
Biogas
Bioethanol
Biodiesel
Non-renewable
Non-Renewable
Non-Renewable
Renewable
Renewable
Renewable
*Comprised of
hydrocarbons
extracted from
crude oil
*Produced during
the crude oil
refinery process
or extracted from
natural gas
pockets in the
Earth
*Harvested from
underneath the
earth through oil
wells
*Sourced from
agricultural
crops (energy
crops) such as
sugar cane,
corn etc.
Comprised
of ester
extracted
from
vegetable
oils and
animal fats
*Easily
transportable
* Transported
via Pipelines,
tankers or rail
cars
*Transported in
liquid form
*Transported via
tanker ships,
trucks, and rail
way networks
*Transported in
the form of
liquified gas
*Transported
mainly via
pipeline networks
or through ships
* Travels in gas
form in pipelines
or in liquified
state (LNG) for
easier transport
e.g. ships etc
*Made from
the
breakdown of
Disposable
organic matter
*Sewage
farms and
rubbish tips
*Transported
through
pipeline
networks,
trucks or
tankers
*Transported
through railway
networks and
trucks
*Transport
ed in large
amount
via ships,
trucks and
railway
networks
Petrol prices
fluctuates
heavily
depending on
the economic
availability
*48 kJg-1
*Low cost for
using LPG
* $ 1.073 per litre
(AUS)
*3 per cubic foot
*$0.22-0.39
USD
*Minimal
expenses for
biogas
$1.45-1.04 USD
$0.63/L
*50-51 kJg-1
*54-56 kJg-1
*26 kg/g-1
29.6 kJ.g-1
*41 kJ.g-1
HSC Chemistry Notes
Environ
-mental Impact
* Contributes a
lot to air
pollution and
the greenhouse
effect
* Pollutes
harmful
chemicals
affecting global
temperatures
and biodiversity
Yr 12 Chemistry
*More
environmentally
friendly then
petrol but still
procures CO2
emissions
* Can be still
extracted through
conventional
means, damaging
the environment
such as mining
etc.
By Tayyab Awais
* Emits CO2
emission into the
environment,
impacting
biodiversity
* Contributor to
global warming as
well
*Overall
reduced
methane
emissions
from occurring
* Reduces
waste disposal
in landfills,
reducing
contamination
of soil horizon
as well.
* 21 times
more effective
than
23/02/2022
* Reduces
greenhouse
gasses by
around 15%
*Requires lots
of land,
resulting in
land
deforestation
etc and land
use change
A
*Overall
produces
less CO2
than diesel
*
Contribute
s less to
Green
House
Gases
*
Reactions of Organic Acids and Bases
Structure and Properties of Functional groups:
Boiling Properties:
Presence of hydrogen bonds between molecules causes higher boiling points for carboxylic acids, amines
and amides, resulting in major impacts on physical properties.
Boiling point for amines:
 The presence of highly polar nitrogen-hydrogen covalent bonds in amines result in strong hydrogen
bonds
 The strength of strong hydrogen bonds explain its high MP and BP compared to alkanes of the same
size

Oxygen is more electronegative than nitrogen, so the difference in electronegativity between oxygen
and hydrogen is more than nitrogen and hydrogen resulting in weaker polar bonds of N-H in amines
compared to O-H bonds in alcohols.
- Therefore, amines have lower boiling and melting points than alcohol due to weaker
intermolecular forces.
Boiling points for Amides:
 Amides have much higher boiling points than related amines because they have more atoms that
can donate or accept hydrogen bonds
 Strong hydrogen form between the non-bonding electron pairs on the oxygen atom of one molecule
and the partially positive hydrogen atom on a neighbouring molecule
pg. 56
HSC Chemistry Notes

Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Why do amides have a higher BP than carboxylic acids?
- Primary amides have more hydrogen atoms bound to a nitrogen which allows for more
hydrogen bonding
- Amides have resonance structures which create ionic charges at the carbonyl oxygen atom and
amide nitrogen atom.
Boiling Points for Carboxylic Acids:
Dimer: a molecule composed of two identical subunits that may be molecules, joined by strong
intermolecular forces, such as hydrogen bonds.

The two molecules of a carboxylic in the liquid state can form dimers in which between the
molecules connected by strong hydrogen bonds

The resulting dimer produced has a molar mass that is double that of a single carboxylic acid
molecule, resulting in stronger dispersion forces

Dispersion forces and hydrogen bonds between molecules result in a higher boiling and melting
point seen in carboxylic acids compared to most other organic molecules of the size.
pg. 57
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Effect of Chain length on
Boiling Point:
 For amines and carboxylic acids, as chain length increases, dispersion forces increase which
complement the existing hydrogen bonds
- As a result, boiling point increase

Amides don't follow same trend due to more complicated bonding structure of amides
- The extensive arrangement of hydrogen bonds produces a complex, non-linear relationship
between hydrocarbon chain length and boiling point in amides
Solubility:
Solubility of small amines, amides and carboxylic acids dissolve completely in soluble in water due to water
forming hydrogen bonds with the polar nitrogen-contain and oxygen-containing functional group.

Solubility decreases as the hydrocarbon chain becomes longer, making it less soluble
Solubility in Organic Solvents: Small amides, amines and carboxylic acids are insoluble in non-polar organic
solvents, but solubility increase as the hydrocarbon chain becomes longer.
- This is because they are less polar due to long hydrocarbon chains, making it soluble in organic
solvents
Ketones and Aldehydes:
Are considered together because they are composed of molecules that containing intermolecular forces
consisting of dipole-dipole interactions.
 Unable to form hydrogen bonds with each other as they do not have a hydrogen atom bonded to an
oxygen or nitrogen atom.

pg. 58
Boiling Point:
- Both contain a carbon-oxygen double bond and is polar due to large differences in
electronegativity between oxygen and carbon.
HSC Chemistry Notes
-

Yr 12 Chemistry
By Tayyab Awais
23/02/2022
As a result, aldehydes and ketones have a permanent dipole which can form dipole-dipole
attractions with nearby molecules
Therefore, higher Melting and boiling points than alkanes but lower than alcohols as dipoledipole interactions is not as strong as hydrogen bonds
Solubility:
- Short chain aldehydes and ketones are soluble in water. The solubility decreases as the chain
becomes longer
-
As the non-polar hydrocarbon chain length of aldehydes and ketones increase, they become
more soluble in polar solvents, similar to the other functional groups.
Simple Esters:
“Esters” are a group of carbon compounds formed by the rection between an alkanol and an alkanoic acid,
catalysed by a strong concentration of sulphuric acid (H2SO4)
- Esterification typically takes a long time, and a complete reaction is unachievable, however, by
using an acid catalyst such as H2SO4 will speed up the process. It acts as a dehydrating agent,
which will push the equilibrium to the right, increasing the yield for esters
alkanol + carboxylic acid  ester + water

This reaction could be described as a condensation reaction as it produces water molecules as well
but it is so widespread and important in nature, that it has its own name for this reaction,
“esterification”
- Esters make up many smells and tastes associated with naturally occurring fruits and other foods

All esters contain this chemical functional group inside the molecule, with hydrocarbon chains on
either side
pg. 59
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
This group of atoms is polar, but both ends of the molecule are non-polar. Esters generally have lowsolubility in water (some exceptions) and are volatile with a strong odour, often sweet and fruity. Esters are
used to give the smells and flavours to many foods and perfumes. Esters tend to be liquids at room
temperature with boiling points much lower than those of alkanoic acids with similar molecular masses. This
is because the intermolecular forces in esters are dispersion and dipole-dipole interactions rather than
hydrogen bonding as in alkanoic acids.

Refluxing is a process which enables vapour escaping from a reaction mixture to condense and
return to the reaction mixture. This prevents loss of volatile reactants (alkanols) or volatile products
(esters) from the reaction mixture.
- Advantage: Refluxing allows esterification to be carried out at higher temperatures than would
otherwise be possible, which increases the rate of reaction.
Naming Estes:
Esters are given two-word names.
First part of the name comes from the alkanol. Drop the -anol and add “-yl”
 E.g., butanol becomes butyl.
The second part of is derived from the carboxylic acid. Drop off the -oic acid and add “-oate”.
 E.g., Ethanoic acid becomes ethanoate.
E.g. Butanol + ethanoic acid  Butyl ethanoate
pg. 60
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Organic acids and bases:
The acidic –COOH functional group, the neutral –CON2 group and the basic –NH2 group support life.
 These functional groups are essential to the structure and function of proteins, the way that energy
is stored and transferred through the body, the way that metal ions like iron and calcium are used in
organisms etc.

Organic acids include carboxylic acids; organic bases include amines.

Organic acids and bases undergo the same reactions as inorganic acids and bases.
pg. 61
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022

Organic acids are weak acids that ionise to different degrees, and react with bases, carbonate, and
active metals.

Organic bases react with acids, for example amines react with acids to form a protonated amine.
Disassociation in Water:
 Ethanoic acid is a weak acid and only dissociates to a small extent in water to form hydronium ions.
Other carboxylic acids react with water in a similar way.

Ethanamine is a weak base and reacts to a small extent with water to form the ethanammonium and
hydroxide ions. The equation for this dissociation reaction is:

ethanamide and other amides are essentially unreactive as either are acids or bases
Soaps and Detergents:
Soaps and detergents are materials, which when dissolved in water, help to clean a surface by removing dirt
or other foreign matter. Both soaps and detergents are surfactants and emulsifiers.
Surfactants: Compounds that lower (reduce) the surface tension between different states of matter (solid,
liquid or gas)
Emulsifying agent: emulsifying agent is a chemical compound that permits the mixing of two or more
immiscible liquid.
- E.g., keep grease and dirt suspended in water so they can be washed away from the object being
washed away.
Chemical representation:
R-COO-NA
R-COO-K
pg. 62
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Soaps:
Soaps are salts of long fatty acids. They consist of a long hydrocarbon chain, or tail with a carboxylate ion
(COO-) at one end – known as the head. A positively charged sodium or potassium ion is bonded to the
carboxylate ion, making the soap molecule a sodium or potassium salt.
The hydrocarbon tail is very non-polar or hydrophobic and will bond to other non-polar substances through
formation of dispersion forces.
Hydrophobic: Hydrophobic is a property of a substance that repels water “dislikes water”
The ionic head is polar due to the presence of the carboxylate ion. It forms dipol-dipole bonds with water,
so is hydrophilic.
Hydrophilic: Hydrophilic refers to having a strong affinity for water “likes water”
Due to this structure soap molecules do not spread out evenly through water, they form little clumps known
as a micelle.
The non-polar grease / dirt molecules move to the centre of the soap clump. The negative ends interact with
water molecules keeping the micelle suspended in water. The non-polar tails of the soap molecules adsorb
onto the grease. The charged heads of the surfactant form a layer around the grease, giving it a hydrophobic
surface. This arrangement of tiny grease particles trapped inside micelles dispersed in water forms a type of
mixture called an emulsion, with the soap acting as an emulsifier (emulsifying agent).
pg. 63
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Soap also acts as a surfactant. They act on the surface of another substance, changing its surface tension. the
fatty acid ions lower the surface tension of water by disrupting the hydrogen bonds between water
molecules. This increases the ability of water to wet a surface and thus to remove any dirt of grease and
clean it.
Detergents
Detergents have a similar structure to soaps, with a long hydrocarbon tail, but vary in the structure of the
polar head.

Anionic detergents – have a negatively charged ion, like soaps, e.g. sulfate ion.

Cationic detergents – have a positively charged ion, e.g. amine.

Non-ionic detergents – have no ionic charge, but will usually have a polar functional group like a
hydroxyl or carboxylic acid group.
pg. 64
HSC Chemistry Notes
pg. 65
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
HSC Chemistry Notes

Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Detergents were synthesised to be used in place of soaps since soaps are ineffective in hard water.
Hard water contains high levels of calcium and magnesium ions.
Properties and uses of detergents table (down below)
TYPE OF DETERGENT
Anionic
USES



Laundry detergents
Dishwashing detergents
Household cleaners
Cationic




Fabric softeners
Hair conditioners
Disinfectants
Sanitisers (for example,
mouthwash)
Non–ionic


Dishwasher detergents
Glass cleaners
CHARACTERISTICS
 Create good lather
 Have a negative charge
 Harsh action (so not
suitable for use as
personal cleaners)
 Cheap
 Bond very strongly to
negatively charged
surfaces (reducing static
friction and tangling)
 Biocidal (kills bacteria)
 Expensive
 Low lather formation
(prevents foam build‐up
in dishwashers)
 Expensive
Making Soap:
Soaps are made through the hydrolysis of fats in a saponification reaction. Fats are triglycerides, molecules
with three hydrocarbon chains containing 10–20 carbon atoms joined to a propane backbone by three
ester bonds.
 When a triglyceride reacts with sodium or potassium hydroxide, the ester bonds break and an
alcohol and three alkyl carbonates form. (Shown below).
pg. 66
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
This is done by boiling a fat or oil with sodium hydroxide. The soap curdles and forms a solid that can
be scraped off and dried to form solid soap. The remaining soap ions in solution are precipitated out by
adding a concentrated solution of sodium chloride, a process known as ‘salting out’.
Organic reaction pathway:
Polymers
Polymer: large molecules
Polymers: A long chain molecule made up of thousands or millions of repeating monomer units.
Polymerisation: Chemical reaction in which many small molecules combine to form one large molecule. Is
broken into two groups;
- Addition polymerisation
- Condensation polymerisation

Synthetic Polymers are often referred to by the general term, plastics.
Some common natural polymers include starch, cellulose, proteins and DNA. Synthetic polymers have been
manufactured and include common plastics such as polyethylene, polyvinyl chloride and polyvinyl acetate.
Such polymers are derived from compounds extracted from crude oil. They are not biodegradable.
Structure and properties for Addition polymerisation:
Addition Polymerisation is the formation of a polymer by adding together monomers through an addition
reaction, without the loss of an atoms during the process (no by-products are formed).
 With this, the double bond breaks ‘opens out’ allowing the carbon with a free electron to form
bonds with other monomers.
pg. 67
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Once a polymer is formed through addition polymerisation, the polymer does not have any unsaturated
carbon bonds, only having a long chain polymer with single bonds present in the chain.
Polyethylene (PE):
Ethene is an important monomer produced by the thermal or catalytic cracking of fractional produced by the
fractional distillation of petroleum.
 Polyethylene chains typically vary in length from 2000 to 30 000 monomers.
(Image of polyethylene structure shown above)
Polyvinyl chloride (PVC):
Commercial PVC polymers typically vary in length from 2000 to 40 000 monomer units. Their chains are
linear, and the polymer is very
strong and
rigid.
Polystyrene (PS):
Polystyrene PS is another important commercial polymer.



pg. 68
Commercial PS polymers typically vary in length from 10 000 to 40 000 monomer
units.
The polymer is quite rigid due to the presence of the large phenyl group. The
phenyl group consists of a hexagonal ring of carbon atoms with delocalised
electrons.
Polystyrene is a hard rigid plastic. It can be converted into polystyrene foam by
heating and using blowing agents to expand the plastic.
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Polytetrafluoroethylene (PTFE):
It is manufactured from the tetrafluoroethylene monomer (CF2CF2). The commercial polymer is called
Teflon
Structure and properties for Condensation polymerisation:
A condensation polymerisation is where there are a variety of polymers can be formed together. Two
functional groups must be present between the monomers on one ends of each monomer.
 Both functional groups must also be able to react chemically with the other functional group for this
process to be possible.
Another key feature of condensation polymerisation that differentiates it from the addition polymerisation is
that small molecules mainly water, ammonia or hydrogen chloride are formed as by-products of the
reaction.

pg. 69
Esterification is a condensation reaction when an alkanoic acid and alkanol react and an ester and
water is produced.
HSC Chemistry Notes
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
Nylon:
It is a condensation polymer formed when a dialkanoic acid and diamine monomers condense with the
elimination of a water molecule. An amide linkage (-CONH-) binds the monomers as the polymer chain
grows.
 Nylon 6,6 is a common plastic that is formed by the condensation polymerisation of hexanedioic acid
and hexan-1,2-diamine
Polyesters:
Polyesters are commercial polymers formed by condensation polymerisation reactions. Polyesters form
when an alkandiol monomer bonds with a dialkanoic acid monomer via an ester linkage (-COO-).
The dimer’s functional groups continue the process, and the polymer chain grows larger. The OH group from
the dialkanoic acid and the H from the hydroxyl functional group of the alkandiol combine to form water.

pg. 70
A common polyester used to make clothing is PET (polyethylene terephthalate).
HSC Chemistry Notes
Addition:
pg. 71
Yr 12 Chemistry
By Tayyab Awais
23/02/2022
pg. 72
By Tayyab Awais

polyethene
Ethylene

Ethene

Com
mon
Syste
matic
Com
mon
System
atic
Chloroethene
Com
mon
polystyrene (PS)
Syste
matic
poly(ethynylbenzene)
Styrene
Ethenylbenzene
Com
mon
Vinyl chloride
Polytetrafluoroethylene (PTFE)
Syste
matic
Polychloroethene
Com
mon

polyvinyl chloride (PVC)
Syste
matic
Systematic
Syste
matic
Polyethylene (PE)
Common
Com
mon
Yr 12 Chemistry


polytetrafluroethene
Com
mon
Mono
mer
Polymer
Monomer
Polymer
Monomer
Polymer
Monomer
Polymer
HSC Chemistry Notes





Polystyrene is covalently
bonded; allows it to be
rigid but is still brittle and
has a low density
Is a stiff thermoplastic due
to the benzene rings and is
mainly lightweight
Polytetrafluoroethylene (PTFE) is
containing properties that entail,
its ability to be non-stick, both
chemically and heat resistant and
lastly is flexible and flame resistant

Tetrafluoroethylene
Properties
LDPE has a low density, are
very flexible however are
not strong
115 degrees- boil point
LDPE contains small
branches in the polymer
resulting in weaker
dispersion forces
HDPE are known for their
high boiling point at
around 135 degrees,
encompass high density
and are tough
HDPE are unbranched
polymers, are packed
more closely
Polyvinyl Chloride (PVC)
dipole-dipole attractions
allows it to be hard and
rigid
PVC is resistant to
chemicals, entails low
flexibility in it
PVC is resistant to water as
well and is a durable
polymer
Polymer is amorphous due
to chlorine atoms sticking
out from chain
This is all possible from the
fluorine atoms that reduce
23/02/2022
Uses / Examples
*Example of Polyethylene’s
everyday activities include plastic
bottles, plastic bags, rubber toys,
cling wrap etc
*Uses for LDPE include cling
wraps, plastic bags, film packaging
material and wash bottles
*HDPE plastics are stronger, being
used for milk containers, bleaches,
plastic buckets, piping and for
insulating wires
PVC has a variety of examples and
uses in real life, this includes;
*Vinyl records
*piping’s
*Electrical wire insulation
*Window frames
*Conveyor belts
*Water pipes

Polystyrene is used in
various fields and utensils
such as
Thermal cups
*Food containers
*Refrigerator parts
*Handles for tools
* CD cases
*Toys
*Styrofoam

Uses for this PTFE include
everyday uses such as
*On non-stick frying pans
*Utensils with Teflon coating
*Medical gear
*Common clothing’s as well
Syste
matic
HSC Chemistry Notes
Yr 12 Chemistry
Tetrafluoroethene
By Tayyab Awais
23/02/2022
the intermolecular bond
stability
Properties

Polymer
Common
Systematic
Nylon: Nylon 6, 6
Poly(azanediyladipoylazanediylhexane-1,6-diyl)






Monomer

Common
Adipic acid and
hexanediamine
Systematic
hexanedioic acid and 1,6diaminohexane


polyesters
Polymer
Common





Systematic
Polyethene
terephthalate (PET)

Monomer

pg. 73
Common
Ethylene glycol and
Terephthalic acid

Uses / Examples
Nylon 6,6 is generally
elastic and sturdy
heat resistant
stable (strong)
Tensile strength for
nylon 6,6 is strong
Forms of this nylon are
also lightweight and
rigid
Strong impact resistance
Nylon is also lustrous
(shiny)
Made from two
different monomers,
making it copolymer
Is also a common nylon
in production

Generally durable,
lightweight, and strong
Have strong resistance
Elastic
Resistant to chemicals
(Alcohols)
Very flexible
Natural state is in a
semi-crystalline resin for
PET
PET Is a thermoplastic
meaning it can be
repeatedly reshaped
and melted
Has these properties
because of dipole-dipole
attractions in the
polymers chains
Also has a rigid benzene
ring















Common uses for
nylon 6, 6 include
clothing’s
Piping systems
High tensile ropes
and threads
Fishing rope lines
Tennis strings
Mechanical
equipment
Seatbelts
Toothbrush bristles
Gun Frames
Used for recyclable
drink bottles
strong food
containers and
packaging’s
Clothing
Jars
Fibres of PET used
in textiles including
clothing
Polyester suits
HSC Chemistry Notes
Systematic
pg. 74
Yr 12 Chemistry
Benzenedicarboxylic acid and
Ethanediol
By Tayyab Awais
23/02/2022