Question

Calculate the change in entropy when $1$ mole nitrogen gas expands isothermally and reversibly from an initial volume of $1$ litre to a final volume of $10$ litre at $27^{\circ} C$.

• A. $19.15\, J\, K ^{-1}$
• B. $20.18\, J\, K ^{-1}$
• C. $16.15 \, J\, K ^{-1}$
• D. $17.16 \, J\, K ^{-1}$

Answer 1

Answer: (A)

$\Delta S =2.303\, n R \log \left(\frac{V_{2}}{V_{1}}\right)$

$=2.303 \times 1 \times 8.314 \log \left(\frac{10}{1}\right)=19.15\, J\, K ^{-1}$