Question

7) Consider the following reaction:

CaCO3(s)→CaO(s)+CO2(g).

Estimate ΔG∘ for this reaction at each of the following temperatures. (Assume that ΔH∘ and ΔS∘ do not change too much within the given temperature range.)

part a) 300 K

part b) 1055 K

part c)1480 K


8) Determine ΔG∘ for the following reaction:


2NO(g)+O2(g)→N2O4(g)


Use the following reactions with known ΔG∘rxn values:


N2O4(g)→2NO2(g), ΔG∘rxn = 2.8 kJ

NO(g)+12O2(g)→NO2(g), ΔG∘rxn = - 36.3 kJ

Answer 1

7)

$$\Delta G _0 = -RTlnK$$

Supposably

$$K = const$$

a)

$$\Delta G _0 = -8.314*300lnK$$

b)

$$\Delta G _0 = -8.314*1055lnK$$

The parameter will be lower by 3.5 than in the case of a

с)

$$\Delta G _0 = -8.314*1480lnK$$

The parameter will be lower by 1.4 than in the case of b and will be lower by 4.9 than in the case of a

8)

$$\Delta G_0 = -2.8 +2*(-36.3) = -75.4 kJ$$