Prove that the volume of a gas at 273°C is twice its volume at 273 K, at constant pressure.

V₁ = Initial volume of the gas = V

T₁ = Initial temperature of the gas = 273 K

T₂ = Final temperature of the gas = 273°C = 273 + 273 = 546 K

V₂ = Final volume of the gas = ?

By Charles' Law:

$\dfrac{\text{V}$1}{\text{T}1} = \dfrac{\text{V}2}{\text{T}2}

Substituting the values :

$\dfrac{\text{V}}{273} = \dfrac{\text{V}$2}{546} \\[1em] \text{V}2 = \dfrac{\text{V}\times 546}{273} \\[1em] \text{V}_2 = 2\text{V} \\[1em]

∴ Volume of a gas at 273°C is twice its volume at 273 K