chemistry 150

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CHEMISTRY 150
October 11th, 2012
NAME:_______________________________
Brian J. MacLean
__________________________________________________________________________________________
INSTRUCTIONS
This quiz should contain a total of eight pages. A periodic table, equations, and other relationships are given on
page 8. Read section instructions carefully. Show all work when solving calculation-style problems.
Question
Marked out of
A 1-10
20
B 1-10
20
C1
10
C2
10
C3
10
C4
10
C5
10
C6
10
Total
100
Obtained
Part A: Multiple choice. Circle the correct answer (a, b, c, or d) to answer the question posed in each case.
A1) Which of the following procedures involves a chemical change?
a) Lighting a candle
b) Separating iron filings from sand using a magnet
c) Boiling salt water to purify it
d) Crushing ice with a hammer
A2) How many total atoms are present in the formula Mg2(OH)2?
a) Three
b) Four
c) Five
d) Six
A3) For the following operation, how many significant figures will the answer have?
(65.65 − 71.3)
=
65.65π‘₯121.30
a) Two
b) Three
c) Four
d) Five
A4) Which of the following is not an exact quantity?
a) The number of ibuprofen tablets held in a container
b) The number of millimetres in 1 kilometre
c) The number of centimeters in 1 inch
d) The number of seconds in 1 hour
A5) For the ruler shown to the right, what is the uncertainty in the measurement scale?
a) +/- 0.1 mm
b) +/- 1 mm
c) +/- 1 cm
d) +/- 10 mm
A6) Which of the following temperatures is not possible?
a) -15K
b) -15oF
c) -15oC
d) 100oC
A7) The mass number of an isotope equals the number of
a) Protons
b) Neutrons
c) Electrons
d) Nucleons
A8) The maximum number of electrons that the 3p subshell can hold is
a) Nine
b) Ten
c) Six
d) Three
A9) Which of the following ions is isoelectronic with neon?
a) Clb) Oc) N3d) Mg+
A10) Which of the following elements is likely to be a good conductor of heat?
a) Barium
b) Sulphur
c) Neon
d) Oxygen
Part B: Fill-in-the-blanks. Enter the word that best completes each sentence in the space indicated.
B1) There is/are ___one__________ uncertain digits in the measured quantity 0.0304 m.
B2) A pure substance that can be broken down into simpler, pure substances by chemical means is called a(n)
_Ccompound____.
B3) A _liquid____ has a defined volume, but no defined shape.
B4) Species that possess different numbers of protons and electrons are called _ions___.
B5) The formula for sodium nitrate is __NaNO3_____.
B6) The full name for the ionic compound, CuO, is __copper (II) oxide_______.
B7) The SI unit for mass is __kg____.
B8) Electrons that possess the same energies are grouped into the same __subshells____.
B9) Atoms of an element which differ only in their numbers of neutrons are called __isotopes___.
B10) Groups of non-metal atoms covalently bound together and which bear a charge are called ___polyatomic
ions_______.
Part C: Problems. Answer each of the following problems. Where appropriate, answer with the proper number
of significant figures and correct units.
C1a) Draw a complete Lewis structure for lithium oxide.
b) Draw a Lewis structure for formaldehyde, H2CO (which has a central carbon atom).
C2a) Write the full electron configuration for phosphorus in the space below, and…
P: 1s22s22p63s23p3
b) answer the following questions:
i.
How many unpaired electrons are present in an atom of fluorine? ___1____
ii.
How many valence electrons are present in an atom of fluorine? ___7____
C3) Calculate the atomic mass for neon, Ne, using the following information:
20
10𝑁𝑒
% abundance
90.92
mass
19.992 amu
21
10𝑁𝑒
0.26
20.994 amu
22
10𝑁𝑒
8.82
21.991 amu
90.92
(19.992 π‘Žπ‘šπ‘’) = πŸπŸ–. πŸπŸ•67264 π‘Žπ‘šπ‘’
100
+
0.26
(20.994π‘Žπ‘šπ‘’) = 0.0πŸ“πŸ’5844 π‘Žπ‘šπ‘’
100
+
8.82
(21.991π‘Žπ‘šπ‘’) = 𝟏. πŸ—πŸ‘96062 π‘Žπ‘šπ‘’
100
= 20.170917 amu = 20.17 amu
C4) Identify which atoms are involved in coordinative covalent bonds in each structure shown, if such a
situation applies, by circling those atoms.
Type equation here.
C5) Cough syrup is to be administered to a patient who weighs 106 lb. The medication’s dosage is 0.2 mL of
cough syrup per kg of body mass. How many teaspoons of cough syrup are required for a single dose?
1 π‘˜π‘”
0.2 π‘šπΏ 1 π‘‘π‘’π‘Žπ‘ π‘π‘œπ‘œπ‘›
(106 𝑙𝑏) (
)(
)(
) = 1.922902494 … π‘šπΏ
2.205 𝑙𝑏
1 π‘˜π‘”
5 π‘šπΏ
But 1 sig fig in answer, so 2 teaspoons.
C6) Complete the following table using the information provided.
Element
Ion Formed
# of electrons in ion
# of protons in ion
phosphorus
P3-
18
15
aluminum
π‘¨π’πŸ‘+
10
13
oxygen
π‘ΆπŸ−
10
8
Equations and other relationships
(some may be useful, some…maybe not)
T ( K ) ο€½ T ( o C )  273.15
given _ units  desired _ units οƒΆοƒ·οƒ· ο€½ desired _ units
 given _ units οƒΈ
density ο€½
mass
volume
1 tablespoon = 3 teaspoons
1 teaspoon = 5 mL
1 kg = 2.205 lb
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