Use standards entropies and heats of formation to calculate delta Gf at 25C for

Question

a. cadmium (II) chloride (s)
b. methyl alcohol, CH3OH (l)
c. copper (I) sulfide (s)

I really have no idea where to start with this problem. I have no idea how to calculate delta Gf, and everything I've tried hasn't worked.

Answer 1

The formation of CdCl2, for example, from its elements, is as follows:
Cd + Cl2 ==> CdCl2
Look up values for So for CdCl2 and Hf for CdCl2. Then dGf = dHf-TdSo

That's all there is to it. For T use 298 K.