Question

The entropy change involved in the isothermal reversible expansion of 2 mole of an ideal gas from a volume of $10d{m}^3$ to a volume of $100d{m}^3$ at ${27}^{\circ }C$ is :

• A. 38.3 J mol⁻¹ K⁻¹
• B. 35.8 J mol⁻¹ K⁻¹
• C. 32.3 J mol⁻¹ K⁻¹
• D. 42.3 J mol⁻¹ K⁻¹

Answer 1

The correct option is A

38.3 J mol⁻¹ K⁻¹

Entropy change for an isothermal reversible process is given by

$\Delta S=nRln\frac{V_2}{V_1}=2\times 8.314\times 2.303log\frac{100}{10}$

= $38.3Jmo{l}^{-1}{K}^{-1}$