Nat 4/5 Rate of Reactions Homework 1
1.
2.
What is a variable?
The next two questions refer to the grid below:
(a)
(b)
Identify the two experiments which could be used to show the effect
of concentration on the rate of reaction.
Identify the experiment with the fastest rate of reaction.
(2)
3.
(a)
(b)
(c)
Identify whether each of the following pairs describe a “fair test” or not:
Zinc powder with 2 mol/l HCl acid AND a zinc lump with 1 mol/l HCl acid.
Glue at 50OC for 15 minutes AND glue at 5OC for 15 minutes.
Marble lumps with 20OC HCl acid AND marble powder with 30OC HCl acid.
(3)
4.
A student added magnesium ribbon to an excess of dilute sulphuric acid
and measured the volume of hydrogen gas produced as it collected in a
syringe. The total volume of hydrogen gas collected as the time progressed
was as follows:
At time 0 seconds there had been no gas produced yet as the reaction
hadn’t started and the reading on the syringe was therefore 0cm3. After
10 seconds the reading on the syringe was 20cm3. At 20 seconds the syringe
read 32cm3. At 40 seconds the reading on the syringe was 50cm3. At 50
seconds the syringe read 52cm3. At 60 seconds the syringe read 53cm3 and
at the final time of 70 seconds the reading on the syringe was once again
53cm3.
(1)
The two questions below should be completed using the data given at the
bottom of the last page:
(a)
(b)
5.
(a)
(b)
(c)
(d)
Put the information into a table with suitable headings.
Select and draw the appropriate type of graph to suit this data.
(4)
What is meant by the rate of a reaction?
Draw a labelled diagram to show one way in which the rate of the reaction
between calcium carbonate chips and hydrochloric acid could be measured.
Draw a brief sketch of what the rate of reaction graph might look like for
your experiment (remember to label both axes).
HINT – We are looking for a curve which shows how the rate changes
with time.
Draw a second line onto your graph to indicate what the curve would look
like if we used calcium carbonate powder instead of chips but kept all other
variables identical.
HINT – What might happen to the steepness of the curve & where it
would level off.
(5)
TOTAL 15 marks
Nat 4/5 Rate of Reactions Homework 2
1.
Kirsty was investigating the reaction of calcium and water. This reaction
produces hydrogen gas. A solution of calcium hydroxide was also formed.
Kirsty collected the hydrogen in a measuring cylinder and obtained the
results shown in the table.
Time/ min
0
4
8
12
16
20
(a)
(b)
(c)
(d)
2.
(a)
(b)
(c)
Volume of hydrogen/ml
0
16
32
44
50
50
Use the information in the passage to help you write the word equation
for the reaction.
Draw a line graph of ‘volume of hydrogen produced’ against ‘time’.
Use your graph to find the volume of hydrogen collected in the first
two minutes of Kirsty’s experiment.
Suggest one way of speeding up the reaction.
(5)
Jenny added lumps of zinc to 100cm3 of 2mol l/l sulphuric acid in a flask.
A reaction took place and bubbles of hydrogen gas were seen. Every two
minutes she noted the mass of the flask and contents.
Time/min
Total mass loss/mg
0
2
4
6
8
10
12
0
130
210
260
300
330
330
Draw a line graph of Total mass loss against Time.
Add a dotted line to show the curve you would expect if the experiment was
repeated using the same mass of powdered zinc.
Why was there a loss of mass from the flask?
(5)
3.
Sam added manganese dioxide to hydrogen peroxide solution and measured
the volume of oxygen produced.
Her results for two experiments at different temperatures are shown in
this graph.
(a)
(b)
(c)
(d)
(e)
What final volume of oxygen was collected in experiment A ?
The same volume and concentration of hydrogen peroxide was used in both
experiments, A and B. How can you tell this from the graph?
At the start experiment B was faster than experiment A.
How can you tell this from the graph?
0.2g of the catalyst, manganese dioxide, was present at the start of
experiment A.
What mass of catalyst would be left at the end of the experiment?
In experiment A how long did it take to produce 25cm3 ?
(5)
TOTAL 15 marks