What is the value of 𝐾 for this aqueous reaction at 298 K?

Question

A+B↽−−⇀C+D Δ𝐺°=23.53 kJ/mol

K=?

Answer 1

A + B ==> C + D ∆Gº = 23.53 kJ/mol (note: value of ∆Gº is positive, meaning a non-spontaneous reaction)

Use ∆Gº = -RT ln K

∆Gº = 23.53 kJ / mol

R = 8.314 J / Kmol = 0.008314 kJ / Kmol (change units to be consistent with units of ∆Gº)

T = 298K

K = ?

Solve for K:

23.53 kJ / mol = -(0.008314 kJ/Kmol)(298) ln K

23.53 kJ/mol = -2.478 kJ/mol ln K

ln K = -10.30

K = 3.35x10^-5 (consistent with a non-spontaneous reaction)