How much heat is produced when 29.6 g of methanol react with 45.9 g of oxygen?
You need to supply the enthalpy of combustion of methanol.
Methanol combusts according to the reaction:
This reaction will be exothermic. Just how exothermic it will be is subject to measurement, which you have not quoted.
Given the molar quantities, there is sufficient dioxygen for complete combustion. However, we still need the molar enthalpy of combustion.