Exercise 6 | Chemical Thermodynamics

Calculate ΔG0rxn for the following acido-basic reaction at 25°C:

CH3COOH (aq) + H2O (l) CH3COO- (aq) + H3O+ (aq)

In which direction will the reaction proceed spontaneously?


Data: Ka [CH3COOH / CH3COO-] = 1.80 x 10-5

ΔG0rxn = - RT ln K

R = ideal gas constant = 8.314 J.mol-1.K-1

T = temperature (in K) ⇒ 25°C = 298 K

K = equilibrium constant = Ka [CH3COOH / CH3COO-] in this exercise

 

ΔG0rxn = - 8.314 x 298 x ln Ka

ΔG0rxn = 27.1 kJ.mol-1

ΔG0rxn > 0: the reaction will proceed spontaneously from right to left