So I have had several homework problem like this and managed to solve them easily, but these two problems I cannot get the correct answer for.

Question

Using a Table of thermodynamic data, calculate the change in Gibbs free energy for each of the following reactions. In each case indicate whether the reaction is spontaneous under standard conditions. Here are some more delta G values: N2H4 (g) = 159.4 kJ/mol, FeO (s) = -255.2 kJ/mol, FeCl3 (s) = -334 kJ/mol, H3PO4 (aq) = -1142.6 kJ/mol

2 NH3(g) N2H4(g) + H2(g)
i got to be 187kj but its wrong.

2 CH3OH(l) + 3 O2(g) 2 CO2(g) + 4 H2O(l)
I got -1693 and its wrong.

Answer 1

I figured it out. I used the deltaH values in the chart instead of the DeltaG value.