You need to use standard heat of formation values to solve this problem. These values detail the heat used when 1 mole of a chemical is produced.
You first need to create a balanced formula for the combustion of ethyl alcohol:
C2H6O + 3 O2 -> 2 CO2 + 3 H2O
Find the standard heat of formations for these chemicals. Add the values (with adjustments for the amount of moles) of the products and subtract the sum of the values of the reactants. This will give you the enthalpy of reaction. Divide 5000. kJ by the enthalpy of reaction to get the amount of moles needed to be combusted.
From moles, you need to convert to grams and then milliliters by using molar mass and density values, respectively.