Question

The volume occupied by a given mass of a gas at 298 K is 25 mL at 1 atmosphere pressure. Calculate the volume of the gas if pressure is increased to 1.25 atmosphere at constant temperature.

Answer 1

Given: P₁ = Initial pressure = 1 atm, V₁ = Initial volume = 25 mL

P₂ = Final pressure = 1.25 atm 

To find: V₂ = Final volume of the gas 

Formula: P₁ V₁ = P₂ V₂ (at constant n and T) 

Calculation: According to Boyle’s law, P₁ V₁ = P₂ V₂

Substituting the values of P₁ , V₁ and P₂ in the above expression, we get

V₂ = \(\frac{P_1V_1}{P_2}\) = \(\frac{1\times 25}{1.25}\) = 20 mL

The volume occupied by the gas is 20 mL.