nature of matter and composition - Category wise Question and Answer Practice Test with Solutions

Question : 26

What happens when a fixed amount of oxygen gas is taken in a cylinder and compressed at constant temperature?

1. Number of collisions of oxygen molecules at per unit area of the wall of the cylinder increase.
2. Oxygen ($O_2$) gets converted into ozone ($O_3$).
3. Kinetic energy of the molecules of oxygen gas increases.

a) C only

b) A and C

c) B and C

d) A only

Question : 27 [CDS]

Aqua-regia used by alchemists to separate silver and gold is a mixture of

a) nitric acid (concentrated) and sulphuric acid (concentrated)

b) hydrochloric acid (concentrated) and nitric acid (concentrated)

c) hydrochloric acid (concentrated) and sulphuric acid (concentrated)

d) hydrochloric acid (dilute) and sulphuric acid (dilute)

Question : 28

Cloud or fog is an example of colloidal system of

a) solid dispersed in gas

b) gas dispersed in gas

c) liquid dispersed in gas

d) solid dispersed in liquid

Question : 29

Which of the following processes is known as fusion?

a) change of liquid to vapour

b) change of liquid to solid

c) change of solid to liquid

d) change of gaseous state to solid state

Question : 30

A gas can be compressed to a fraction of its volume. The same volume of a gas can be spread all over a room. The reason for this is that

a) gases consist of molecules having very large intermolecular space which can be reduced or increased under ordinary conditions

b) the volume occupied by molecules of a gas is negligible as compared to the total volume of the gas.

c) gases consists of molecules which are in a state of random motion

d) None of these