Practice Problem 6

Calculate H° and S°   for the following reaction:

NH₄NO₃(s)  + H₂O(l)    NH₄⁺ (aq) + NO₃^- (aq)

Use the results of this calculation to determine the value of G^o for this reaction at 25^o C, and explain why NH₄NO₃ spontaneously dissolves is water at room temperature.

Answer

H^o = 28.05 kJ

S^o = 108.7 J/K

G^o = -4.4 kJ