Which of the reactions are spontaneous (favorable)?

Question

a. 2H2O(g)⟶2H2(g)+O2(g) Δ𝐺=457 kJ/mol

b. CH4(g)+2O2(g)⟶CO2(g)+2H2O(l) Δ𝐺=−820 kJ/mol

c. 2Mg(s)+O2(g)⟶2MgO(s) Δ𝐺=−1137 kJ/mol

d. C(s)+H2O(l)⟶CO(g)+H2(g) Δ𝐺=90.8 kJ/mol

e. AgCl(s)⟶Ag+(aq)+Cl−(aq) Δ𝐺=55.6 kJ/mol

f. NH3(g)+HCl(g)⟶NH4Cl(s) Δ𝐺=−91.1 kJ/mol

Answer 1

Reactions are spontaneous if dG is negative.