Question

Energy of all molecules of a monatomic gas having a volume V and pressure P is $\frac{3}{2}PV$. The total translational kinetic energy of all molecules of a diatomic gas at the same volume and pressure is

• A. $\frac{1}{2}PV$
• B. $\frac{3}{2}PV$
• C. $\frac{5}{2}PV$
• D. $3PV$

Answer 1

Answer: (B)

$\frac{3}{2}PV$

The no of translational degrees of freedom for mono atomic or diatomic gas is same and is 3.
Hence, translational KE will be same at same temp for both gases.
Mono atmic gas has only translational degree of freedom.
Hence, translational kinetic energy for diatomic gas is $\frac{3}{2}PV$