Estimate Keq for the following equilibria at 425 K. Note that H2O is present as a gas rather than as a liquid. R = 8.3149 J/(mol*K).
Substance ?Ho(kJ/mol) So(J/(mol*K))
SnO2(s) -577.6 49.0
H2(g) 0 130.680
CO(g) -110.5 197.7
Sn(s, white) 0 51.2
H2O(g) -241.83 188.835
Fe(s) 0 27.3
Fe3O4(s) -1118.4 146.4
SnO2(s) + 2H2(g) Sn(s, white) + 2H2O(g)
3Fe(s) + 4H2O(g) Fe3O4(s) + 4H2(g)