AH; (kJ/mol) -92.30 -268.60 25.9 - 74.80 -238.6 Standard enthalpies of formation Substance Formula AHF (kJ/mol) Substance Formula Acetylene C2H2(g) 226.7 Hydrogen chloride HCI(g) Ammonia NH3(g) -46.19 Hydrogen fluoride HF(g) Benzene C6H6C) 49.0 Hydrogen iodide HI(g) Calcium carbonate CaCO3(s) -1207.1 Methane CH4(g) Calcium oxide CaOs) -635.5 Methanol CH3OH() Carbon dioxide CO2(g) -393.5 Propane C3H2(g) Carbon monoxide CO(g) -110.5 Silver chloride AgCl(s) Diamond C(s) 1.88 Sodium bicarbonate NaHCO3(s) Ethane C2H6(9) -84.68 Sodium carbonate Na2CO3(s) Ethanol C2H5OH(1) -277.7 Sodium chloride NaCl(s) Ethylene C2H49) 52.30 Sucrose C12H22011(s) Glucose C6H12O6(s) -1273 Water H2O(1) Hydrogen bromide HBr(g) -36.23 Water vapor H2O(g) -103.85 -127.0 -947.7 -1130.9 - 410.9 -2221 -285.8 -241.8 17. Consider the reaction CH4(g) + 2 O2(g) + CO2(g) + 2 H2O(l). (a) Calculate AHrxn for the reaction as written (b) Check the box below for only one correct statement. The reaction is ... endothermic I exothermic thermoneutral Not enough information to tell (c) Assume the reaction is carried out in an apparatus that keeps the temperature and pressure of the reaction system constant. Will the reaction system perform work on the surroundings or will the environment perform work on the system? Check the box below for only one correct answer. Work will be performed ... by the surroundings on the system by the system on the surroundings No work will be performed (w = 0) Not enough information to tell (Remember: PV = nRT)