JEE Advanced levelOne or more correct optionsDifficulty 3 of 3td108
For AB at 300K, ΔG∘=+4.00kJmol−1. Use R=8.314Jmol−1K−1. Select the correct statement(s).
AFor Q=0.100, ΔG≈−1.7kJmol−1 and the net reaction goes forward
BK≈0.20, so [B]/[A]≈0.20 at equilibrium
CFor Q=1.00 the net reaction goes forward because B and A are at equal concentrations
DAt equilibrium ΔG=ΔG∘=+4.00kJmol−1
Answer: A, B
K=exp(−4000/(8.314×300))=0.201. For Q=0.100: ΔG=4000+2494.2ln(0.100)=−1.74kJ, negative, so forward. For Q=1.00: ΔG=ΔG∘=+4.00kJ>0, so the net change is backward (Q>K). At equilibrium ΔG=0 always, not ΔG∘.