JEE Main levelSingle correct optionDifficulty 2 of 3td196
For a reaction ΔH∘=−40.0kJmol−1 and ΔS∘=−100Jmol−1K−1 (temperature independent). Taking R=8.314Jmol−1K−1, the equilibrium constant at 500K is nearest to
A0.090
B11.1
C61.4
D1.0
Answer: A
ΔG∘(500K)=−40000−500×(−100)=+10000Jmol−1. K=exp(−ΔG∘/RT)=exp(−2.406)=0.090. The value 61.4 is K at 298K.