Using Thermodynamic data from your notes, calculate the change in Gibbs free energy for each of the following reactions using Gf's. In each case indicate whether the reaction is spontaneous under standard conditions.
2 CH4(g) C2H6(g) + H2(g)
2 NOCl(g) 2 NO(g) + Cl2(g)
MgCl2(s) + H2O(l) MgO(s) + 2 HCl(g)