nehc20040309 nehc20040309 04-10-2022 Chemistry Answered The standard enthalpies of formation of gaseous pro- pyne (CHA), propene (CH6), and propane (CHg) are +185.4, +20.4, and -103.8 kJ/mol, respectively. (a) Calculate the heat evolved per mole on combustion of each substance to yield CO»(8) and H20(g).