Question

Classify each of the following reactions as one of these four types:

• spontaneous at all temperatures

• not spontaneous at any temperature

• spontaneous below a certain temperature but not above

• spontaneous above a certain temperature but not below See Table 17.1 in Tro, Fridgen and Shaw.

(a) C2H2 (g) + 2 H2 (g) → C2H6 (g); ∆H = -311.4 kJ; ∆S = -232.7 J/K

(b) 4 Ag (s) + CO2 (g) → 2 Ag2O (s) + C (s); ∆H = 331 kJ; ∆S = -136 J/K

(c) 2 NH3 (g) → N2 (g) + 3 H2 (g); ∆H = 92.2 kJ; ∆S = 198.8 J/K

(d) 4 NaNO3 (s) + 5 C (s) → 2 Na2O (s) + 5 CO2 (g) + 2 N2 (g); ∆H = -924 kJ; ∆S = 1107 J/K

Answer 1