Compute heat of reaction using heat of formation values

Question

1. Given the following heat of formation values, calculate the heat of reaction for:

C₃H_8(g) + O_2(g)® CO_2(g) + H₂O_(l)

DH_f values in kJ/mol for: C₃H_8(g) = -103.8, O_2(g) = 0, CO_2(g) = -393.5, H₂O_(l) = -285.8.

2. Consider the combustion of ethane (C₂H₆):

C₂H_6(g) + O_2(g)® CO_2(g) + H₂O_(l)

If DG° (in kJ/mol) for: C₂H_6(g) = -32.9, O_2(g) = 0, CO_2(g) = -394.4, and H₂O_(l) = -237.2; calculate DG° for the reaction.