Finding the heat liberated per g of a fuel ?

What you wish to calculate is called Calorific value: This is given as the amount of heat liberated on complete combustion of 1g of a fuel. It is also called fuel value. Now enthalpy of combustion of ethanol is given as -1300kJ.mole. and 1 mole ethanol is 46g/mol. So -1300/46 = -28.26kJ/g is its calorific value.