The related equation for the formation of ethanol is.
2C(graphite)+3H2(g)+
1
2
O2(g)⟶C2H5OH(l);∆Hf=−277.7kJ/mol
When 2 moles of graphite is involved the standard enthalpy of reaction is −277.7kJ/mol ∴ When 4 moles of graphite is involved, standard enthalpy of reaction is 2×(−277.7kJ/mol) =(−)555.4kJ/mol