Question

$2$ mole of ideal gas at $27^{\circ}C$ temperature is expanded reversibly from $2\,L$ to $20\,L$ . Find entropy change $(R=2\,cal/mol\,K)$

• A. 92.1
• B. 0
• C. 4
• D. 9.2

Answer 1

Answer: (D)

9.2

Answer 2

$\Delta S$ (Entropy change) $=2.303\, n R\, \log _{10} \frac{V_{2}}{V_{1}}$ $= 2.303 \times 2 \times 2 \times \log _{10} \frac{20}{2}$ $=2.303 \times 2 \times 2 \times 1$ $=9.212\, cal$