Determination of Standard Molar Enthalpy of Formation for Crystalline endo-Tricyclo[5.2.1.02,6]decane by an Isoperibol Oxygen-Bomb Combustion Calorimeter

摘要

The construction and principle of the new-established isoperibol oxygen-bomb combustion calorimeter are described. The energy equivalent (?Caior) of the calorimeter has been determined from ten combustion experiments using about 0.7 g of NIST 39i benzoic acid with a certified mass energy of combustion, ACU = -(26434 ± 3) J g-1, under experimental conditions: ?caior = (13572 ± 2) J K-1. The constant-volume energy of combustion of the compound, endo-tricyclo[5.2.1.02'6Jdecane (C10H16), has been determined to be A[/c(CioHi6, s) = -(6070 ± 3) kJ mol-1 by means of the oxygen-bomb combustion calorimeter at T - (298.15 ± 0.001) K. The standard molar enthalpy of combustion of the sample has been calculated, Ac//m(CioHi6, s) = -(6060 ± 3) kJ mol-1, from the constant-volume combustion energy. From the Hess thermochemical cycle, the standard molar enthalpy of formation of the compound has been determined, Af/f?,(CioHi6, s) = -(161.83 ± 3.55) kJ mol-1.