Question

A given mass of ideal gas has volume (V) at pressure (P) and the room temperature. If its pressure is first increased by 50% and then decreased by 50% (both at constant temperature only), the volume becomes.

• A. 4V/3
• B. V
• C. 3V/4
• D. 4V/5

Answer 1

Answer: (A)

$P_1{V}_1=P_2{V}_{2}Firstincreasedby50i.e{P}_2=1.5P_1{V}_2=\frac{1}{1.5}{V}_{1}Nowdecreasedby50i.e{P}_3=\frac{P_2}{2}=\frac{1.5}{2}{P}_1{P}_2{V}_2=P_3{V}_3{V}_3=2V_2{V}_3=\frac{2}{1.5}{V}_1{V}_3=\frac{20}{15}{V}_1=\frac{4}{3}{V}_1$