Calculate the standard Gibbs free energy of reaction in each of the

Calculate the standard Gibbs free energy of reaction in each of the following using the standard molar entropy values given. Express your answers to 3 significant figures in kJmol1, and in each case state whether the reaction is spontaneous or not under standard conditions.

(Values for Sθin J K–1 mol–1: Ag2CO3(s) = 167.4,

Ag2O(s) = 121.3, CH4(g) = 186.2, Cl2(g) = 165,

CO2(g) = 213.6, H2(g) = 130.6, HCl(g) = 186.8,

H2O(l) = 69.9, Mg(s) = 37.2, MgCl2(s) = 89.6,

Na(s) = 51.2, Na2O2(s) = 95.0, O2(g) = 205.0)

a. H2(g) + Cl2(g) → 2HCl(g)                                           ΔHθreaction=–184.6 kJ mol–1

b. CH4(g) + 2O2(g) → CO2(g) + 2H2O(l)                      ΔHθreaction=–890.3 kJ mol–1

c. 2Na(s) + O2(g) → Na2O2(s)                                      ΔHθreaction=–510.9 kJ mol–1

d. Mg(s) + Cl2(g) → MgCl2(s)                                       ΔHθreaction=–641.3 kJ mol–1

e. Ag2CO3(s) → Ag2O(s) + CO2(g)                               ΔHθreaction=+167.5 kJ mol–1