Question

What is the effect of pressure on gas?
(a)- Volume of the gas decreases with increases in pressure
(b)- Volume of gas increases with increases in pressure
(c)- Both (a) and (b)
(d)- Pressure does not affect gas

Answer 1

Solids, liquids, and gases are differentiated based on space occupied by the molecules present in it. In solids, the molecules are very close, in liquids the molecules are little close, but in gases, the molecules are very far from each other. So when pressure is applied, the molecules come closer to each other.

Complete step by step answer:
Gases are those substances in which the molecules are sufficiently apart from each other. This makes the gas occupy a large space.
Since the molecules are very far from each other, they have very low intermolecular forces between the molecules. This means that the volume of gas is very large.
So, on applying the force on gas, the molecules come close to each other. This increases the intermolecular forces between the molecules of the gas. This makes the gas occupy less space or we can say that the volume of the gas decreases.
Therefore, the pressure of the gas is inversely proportional to the volume of the gas.
$P\propto \dfrac{1}{V}$

When the pressure increases, the gas may convert into a liquid, and on further increasing the pressure, it may convert into a solid.
So, the correct answer is - Volume of the gas decreases with increases in pressure.
So, the correct answer is “Option A”.

Note: When pressure is applied on solids there is no effect on the volume because the molecules are very close to each other. The volume of the gas decreases on increasing pressure, this observation was done by Robert Boyle at a constant temperature.