Answer is: enthalpy is -1276,8 kJ.
Chemical reaction: 2CH₃OH(l) + 3O₂(g) → 2CO₂(g) + 4H₂O(g).
ΔH(CH₃OH) = -238,7 kJ/mol.
ΔH(H₂O) = -241,8 kJ/mol.
ΔH(CO₂) = -393,5 kJ/mol.
ΔH(O₂) = 0 kJ/mol.
ΔHreaction = ∑ΔHproducts - ∑ΔHreactants
ΔHreaction = (2·(-393,5) + 4·(-241,8) - (2·(-238,7))
ΔH = (-787 - 967,2) + 477,4
ΔH = -1276,8 kJ.
