How do you calculate free energy?

Question

How do you find the ΔG of this reaction and is this reaction favorable or unfavorable?

2 AgNO₃ + CaCl₂ → 2 AgCl + Ca(NO₃)₂

Substance	S (J/mol⋅K)	Hf (kJ/mol)
CaCl2 (aq)	60	-795.8
AgNO3 (aq)	220	-101.7
Ca(NO3)2 (aq)	240	-938.2
AgCl (s)	96	-127.1

Answer 1

Take the ∆G of the sum of products and subtract the sum of the reactants.

Products:

(2 x -127.1) + (-938.2) = -254.2 + -938.2 = -1192.4 kJ/mol

Reactants:

(2 x -101.7) + (-795.8) = -203.4 + -795.8 = -999.2 kJ/mol

∆_Greaction = Products - reactants = -1192.4 - (-999.2) = -193.2 kJ/mol

Because ∆G is negative, the reaction is favorable.