PART B - RATE OF REACTION
1. When calcium carbonate reacts with hydrochloric acid, carbon dioxide gas is
produced. A convenient way of following the reaction is to place a flask containing the
reactants on a chemical balance and follow the mass of the apparatus with time. As
carbon dioxide escapes from the flask it loses mass.
The results of such an experiment are shown below.
235
MASS (g)
234.5
234
233.5
233
232.5
232
0
1
2
3
4
TIME (MINUTES)
(a)
A.
B.
C.
D.
What was the final mass of the apparatus when the reaction stopped?
232.6 g
232.3 g
232.5 g
232.7 g
(b)
A.
B.
C.
D.
When did the reaction stop?
3.0 min
3.5 min
4.0 min
4.5 min
-1-
5
PART B - RATE OF REACTION
(c)
A.
B.
C.
D.
What was the total loss in mass?
2.1 g
2.2 g
2.4 g
2.5 g
(d)
A.
B.
C.
D.
What mass of carbon dioxide has been produced at time = 1.25 minutes?
1.4 g
1.6 g
1.8 g
2.0 g
A diagram of the apparatus used to follow the above reaction is shown below
COTTON WOOL PLUG
CONICAL FLASK
CALCIUM
CARBONATE AND
HYDROCHLORIC ACID.
CHEMICAL
BALANCE
(g)
A.
B.
C.
D.
The purpose of the cotton wool plug is
To seal the flask and prevent any gas or acid spray leaving the flask
To prevent acid spray leaving the flask, but allow carbon dioxide through
To prevent carbon dioxide leaving the flask, but allow acid spray through
To allow both acid spray and carbon dioxide gas to leave the flask
(h) A very bright pupil said that some of the carbon dioxide gas might dissolve in the
acid solution. She argued that the acid solution contains a lot of water and she knew that
carbon dioxide gas dissolves in fizzy drinks which also contain a lot of water.
If some of the carbon dioxide did dissolve in the acid then
A. The masses recorded will be smaller than they should be
B. The masses recorded will be larger than they should be
C. The masses recorded will be unaffected by any carbon dioxide dissolving
D. It is impossible to say what effect this will have on the masses recorded.
-2-
PART B - RATE OF REACTION
2. The graph below shows the volume of gas produced when calcium carbonate reacts
with dilute hydrochloric acid to produce carbon dioxide gas. The volume of gas was
measured against time.
70
VOLUME (cm3)
60
50
40
30
20
10
0
0
20
40
60
TIME (SECONDS)
(a)
A.
B.
C.
D.
When did the reaction stop?
At 60 seconds?
At 80 seconds?
At 100 seconds?
At 120 seconds?
(b)
A.
B.
C.
D.
What was the final volume of gas produced?
64 cm3
54 cm3
44 cm3
34 cm3
(c)
A.
B.
C.
D.
The volume of gas produced after 35 seconds was
24 cm3
34 cm3
44 cm3
54 cm3
-3-
80
100
PART B - RATE OF REACTION
(d)
A.
B.
C.
D.
The time taken to produce 30 cm3 of gas was
23 seconds
13 seconds
33 seconds
8 seconds
(e)
A.
B.
C.
D.
The reaction was fastest at
time = 20 seconds
time = 80 seconds
time = 50 seconds
time = 0 seconds
3. Which of the following would increase the rate of a chemical reaction?
A. Keeping the mass constant but increasing the particle size
B. Decreasing the temperature
C. Increasing the concentration
D. Decreasing the concentration
4.
A.
B.
C.
D.
Which of the following would decrease the rate of a chemical reaction?
Keeping the mass constant but increasing the particle size
Keeping the mass constant but decreasing the particle size
Increasing the temperature
Increasing the concentration
5. The reaction between copper (II) carbonate and sulphuric acid produces carbon
dioxide gas. Which of the following conditions will give the fastest rate of reaction?
Concentration of acid
Temperature of acid
Particle size of copper (II)
/ mol l-1
carbonate
/ C
1
20
Lump
A
1
30
Powder
B
2
20
Lump
C
2
30
Powder
D
6. The reaction between magnesium metal and sulphuric acid produces hydrogen gas.
Which of the following conditions will give the slowest rate of reaction?
Concentration of acid
Temperature of acid
Particle size of copper (II)
-1
/ mol l
carbonate
/ C
1
20
Lump
A
1
40
Powder
B
2
20
Lump
C
2
40
Powder
D
-4-
PART B - RATE OF REACTION
7. Hydrogen peroxide decomposes produce oxygen gas. The reaction is catalysed by
manganese (IV) oxide. Which of the following conditions will give the fastest rate of
reaction?
Concentration of
Particle size of
Temperature of hydrogen
hydrogen peroxide
manganese (IV) oxide
peroxide
-1
/ mol l
/ C
2
Lump
20
A
2
Powder
30
B
1
Powder
20
C
0.5
Lump
30
D
-5-