(products)-(reagents) ALWAYS! so the answer is 933.7kJmol-1
Again, products – reactants. But in this case…
[716.7+(121.3*4)] – (-95.7) = 1297.6
1297.6 / 4 = 324.4 kJ * m -1
CCl4 (g) -> C (g) + 4Cl (g)
Hrxn = delta Hbond [reactants] – deltaHbond [product]
There are no bonds in the product, so the equations become
delta Hrxn = 4(delta H -carbon chloride)
Solve the bond enthalpy of C-Cl
delta H (c-cl) = delta Hrxn/4
This will give you your final answer.