Determine K for a reaction at 200 K if ∆G° =29.6 kJ/mol. (R = 8.314 J/mol ･ K)

Answer 1

∆Gº = -RT ln K

∆Gº = 29.6 kJ / mol

R = 8.314 J / molK = 0.008314 kJ / molK (change units to agree with those of ∆Gº)

T = 200K

K = ?

Plugging in the values and solving for K:

29.6 = -(0.008314)(200) ln K

29.6 = -1.6628 ln K

ln K = -17.80

K = 1.86x10^-8

This makes sense since ∆Gº is positive, meaning it is a non-spontaneous reaction.