# Boyle’s Law

Robert Boyle, in 1662, showed the relationship between the pressure and the volume of a gas at constant temperature. This is called “Boyle’s Law”. According to Boyle’s Law

### Statement

At constant temperature, the volume of a given mass of gas is inversely proportional to the pressure applied on it

and

At constant temperature, the product of pressure and a volume of a given mass of a gas is always constant.

#### Mathematic Expression:

Mathematically it may be written as
V ∞ 1 / P
Or V = K / P
Or PV = K

#### Explanation:

It means that the increase in pressure would result in a decrease of volume of a gas, similarly the decrease in pressured result in the increase in the volume.Simply we can say, if the pressure is doubled, the volume becomes half and if the pressure is reduce to half, the volume becomes double.

Consider for a given mass a gas having volume V1 at pressure P1, so according to Boyle’s Law we may write as
P1V1 = K1 (constant)
If the pressure of the above system is changed from P1 to P2 then the volume of the gas will also change from V1 to V2. For this new condition of the gas we can write as,
P2V2 = K2 (constant)
But for the same mass of the gas.
K1 = K2
P1V1 = P2V2
This equation is known as Boyle’s Equation