Question

For a reaction, $P+Q\to R+S$. The value of $\Delta H^0$ is -30 kJ $mo{l}^{-1}$ and $\Delta S$ is -100 J $K^{-1}mo{l}^{-1}$. At what temperature, will the reaction be at equilibrium?

• A. ${27}^{0}C$
• B. ${52}^{0}C$
• C. ${30}^{0}C$
• D. ${45}^{0}C$

Answer 1

Answer: (A)

${27}^{0}C$

From Gibbs-Helmholtz equation ,$\Delta G=\Delta H-T\Delta S$,.

At equlibrium, $\Delta G=0$

Hence, $\Delta H-T\Delta S=0$

or, $30000=T\times 100$

Therefore, $T=300K$ or ${27}^{0}C$

Hence, the correct answer is option $\text{A}$.