Question

Enthalpy of a reaction at 27^oC is 15 kJ mol^-1. The reaction will be feasible if entropy is

• A. 15 J mol^-1 K^-1
• B. -50 J mol^-1 K^-1
• C. Greater than 50 J mol^-1 K^-1
• D. Less than 50 J mol^-1 K^-1

Answer 1

Answer: (C)

$\Delta \text{G}<\Delta \text{H}-\text{T}\Delta \text{S}$ for spontaneous reaction

$\Delta \text{G}shouldbe-\text{ve}$

$\text{T}\Delta \text{S}>\Delta \text{H}$

i.e., $300\Delta \text{S}>\text{15000 J}$

$\Delta \text{S}>\text{50 J}{\text{mol}}^{\text{-1}}{\text{K}}^{\text{-1}}$