Using data from thermodynamic quantities at 298.15K, calculate deltaG^degree for the following reactions. Indicate if each reaction is spontaneous at 298K under standard conditions.
(a) 2SO2(g) + O2(g) -> 2SO3(g)
(b) NO2(g) + N2O(g) -> 3NO(g)
(c) 6CL2(g) + 2Fe2O3(s) -> 4FeCl3(s) + 3Oc(g)
(d) SO2(g) + 2H2(g) -> S(s) + 2H2O(g)