5. Thermodynamics and thermochemistry — Chemistry STD 11 Science — Question

$\Delta S=n C_{ v } \ln \frac{T_{2}}{T_{1}}+n R \ln \frac{V_{2}}{V_{1}} \cdots \cdots( I )$

The volume remains zero for isochoric process.

For diatomic gas;

$C_{ v }=\frac{5 R}{2}$

Substitute all the values in the expression $(I)$.

$\Delta S=1 \times \frac{5 R}{2} \ln \frac{500}{300}$

$=\frac{5}{2} \times 8.314 \times 0.5108$

$=10.61\,J$