Question

Q7. Figures below depict air enclosed in a cylinder by an air-tight piston.The piston has been pushed as shown in the figure (ii) so that the air occupies one-third of the length of the cylinder it previously occupied

What would happen to

(a)number of molecules of air?

(b)Volume of the air?

(c)pressure of the air?

(d)what is the normal atmospheric pressure in terms of height of mercury?

Answer 1

Answers are given below.

Explanation:

• The number of molecules will remain the same. After applying pressure the space between air molecules is reduced and they will get closer to each other.
• The volume of the air will be reduced to 1/3 rd of the original volume. As the molecules are compressed so volume will be reduced.
• The pressure of the air increases as piston is pushed down.
• The normal atmospheric pressure is 101325 Pascal.