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Low‐Temperature Heat Capacities and Standard Molar Enthalpy of Formation of Gramine (C 11 H 14 N 2 )
Author(s) -
Chen Jingtao,
Kong Yuxia,
Di Youying,
Yang Weiwei,
Tan Zhicheng
Publication year - 2011
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.201180392
Subject(s) - chemistry , calorimeter (particle physics) , enthalpy , thermodynamics , standard enthalpy of formation , combustion , standard enthalpy of reaction , heat of combustion , adiabatic process , heat capacity , atmospheric temperature range , calorimetry , polynomial , analytical chemistry (journal) , organic chemistry , physics , detector , electrical engineering , engineering , mathematical analysis , mathematics
Low‐temperature heat capacities of gramine (C 11 H 14 N 2 ) were measured by a precision automated adiabatic calorimeter over the temperature range from 78 to 401 K. A polynomial equation of heat capacities as a function of temperature was fitted by least squares method. Based on the fitted polynomial, the smoothed heat capacities and thermodynamic functions of the compound relative to the standard reference temperature 298.15 K were calculated and tabulated at 5 K intervals. The constant‐volume energy of combustion of the compound at T =298.15 K was measured by a precision oxygen‐bomb combustion calorimeter as Δ c U =−(35336.7±13.9) J·g −1 . The standard molar enthalpy of combustion of the compound was determined to be Δ c H m 0 =−(6163.2±2.4) kJ·mol −1 , according to the definition of combustion enthalpy. Finally, the standard molar enthalpy of formation of the compound was calculated to be Δ; c H m 0 =−(166.2±2.8) kJ·mol −1 in accordance with Hess law.