Given the following data:

Question

4PCl5(s) �¨ P4(s) + 10Cl2(g) ƒ¢H = +1774 kJ
P4(s) + 6Cl2(g) �¨ 4PCl3(l) ƒ¢H = -1278.8 kJ

Find the ĢH of the following reaction:

PCl5(s) �¨ PCl3(l) + Cl2(g)