What’s the enthalpy change for the reaction?

Answer:
1075KJ/mol
Explanation:
The enthalpy change is the sum of all the heats of formation in the product - the sum of all the heats of formation in the reactants.
So the reaction being:
CS2 + 3O2 -> CO2 + 2SO2
And the given heat of formation per mole of molecule being:
CS2 = 87.9
O2 = 0
CO2 = -393.5
SO2 = -296.8
You just do:
(2(-296.8) -393.5) - (3(0) + 87.9) = 1075KJ/mol
Remember that I said per mole, so you have to multiply each heat of formation by the number of mole present in the reaction.
Hope that helps