Write reactions for which the enthalpy change will be a. Hf for solid aluminum oxide. b. The standard enthalpy of combustion of liquid ethanol, C2H5OH(l ). c. The standard enthalpy of neutralization of sodium hydroxide solution by hydrochloric acid. d. Hf for gaseous vinyl chloride, C2H3Cl(g). e. The enthalpy of combustion of liquid benzene, C6H6(l ). f. The enthalpy of solution of solid ammonium bromide.