To calculate the enthalpy of combustion of ethanol, we need to first determine the number of moles of ethanol burned and then use the heat energy produced to find the enthalpy change per mole of ethanol.First, let's find the molar mass of ethanol C2H5OH :C: 12.01 g/mol 2 carbon atoms H: 1.01 g/mol 6 hydrogen atoms O: 16.00 g/mol 1 oxygen atom Molar mass of ethanol = 2 12.01 + 6 1.01 + 16.00 = 24.02 + 6.06 + 16.00 = 46.08 g/molNow, let's find the number of moles of ethanol burned:moles of ethanol = mass of ethanol / molar mass of ethanolmoles of ethanol = 45.1 g / 46.08 g/mol = 0.978 molesWe are given that 145.5 kJ of heat energy is produced when 45.1 g 0.978 moles of ethanol is burned. To find the enthalpy of combustion per mole of ethanol, we can use the following equation:H_combustion = heat energy produced / moles of ethanolH_combustion = 145.5 kJ / 0.978 moles = 148.8 kJ/molThe enthalpy of combustion of ethanol is approximately 148.8 kJ/mol.