1. Section A
1. The rate of a chemical reaction cannot be determine by measuring
A the volume of gas liberated per unit time.
B the formation of precipitate per unit time.
C the change of colour per unit time.
D the change of size of solid per unit time.
2. Table shows the volume of oxygen gas liberated at each interval of 4 minutes when
a little manganese (IV) oxide powder is added to hydrogen peroxide solution.
Time interval Volume of oxygen
(min) (cm3)
0–4 28
4–8 18
8 – 12 6
12 – 16 2
16 – 20 0
Which of the following conclusions can be made based on the information in the
above table?
I total volume of oxygen gas liberated is 54 cm3.
II Hydrogen peroxide is completely decomposed during the time interval of 16 to 20
min.
III rate of decomposition of hydrogen peroxide decreases with time.
IV total volume of oxygen gas liberated depends on the mass of manganese (IV)
oxide used.
A I and III only
B II and IV only
C I, II and III only
D I, II, III and IV
3. In an experiment, a little manganese (IV) oxide powder, as a catalyst , is added to 20
cm3 of sodium chlorate (I) solution. The graph for the volume of oxygen gas
liberated against time is shown below.

2. The instantaneous rate of liberation of oxygen gas at 60 seconds, in cm3s-1, is
A 72
B 0
72
C
60
60
D
72
4. A conical flask excess dilute nitric acid and a piece of marble is placed on
an electronic balance, as shown in figure.
The mass of the conical flask and its contents is recorded at regular time intervals.
Which of the following graphs shows the correct plot of the mass of conical flask
and its contents against time?