Charles’s Law

vJacques Charles carried out experiments on ideal gas and observed a relationship between the absolute temperature and volume of gases at constant pressure. Volume of the gas increases with increase in temperature and decreases with decrease in temperature. The Charle’s law can be stated as: ‘that the volume of a sample of gas is directly proportional to the absolute temperature when pressure remains constant’.

Charles’s law can be expressed as follows.

where V is volume and T is absolute temperature of the gas.

For two different conditions 1 and 2, Boyle’s law can be expressed as

where T₁ and V₁ are absolute temperature and volume, respectively, at condition 1 and T₂ and V₂ are absolute temperature and volume, respectively, at condition 2.

Example 1.26: A container of a gas has a volume of 360 ml at a temperature of 20°C. What volume will the gas occupy at 60°C?

Solution:

Given: V₁ = 360 ml; T₁ =273 + 20 = 293 K; T₂ = 273 + 60 = 333 K; V₂ = ?.