摘要 : The enthalpy of formation can be determined indirectly with different calorimetric techniques; one of the most used is combustion calorimetry. During a combustion process, there are multiple energy variables that can significantly... 展开 The enthalpy of formation can be determined indirectly with different calorimetric techniques; one of the most used is combustion calorimetry. During a combustion process, there are multiple energy variables that can significantly influence the overall result of the measurement. One of these variables is the energy exchange that exists between the calorimeter and the surroundings. To reduce this energy contribution and obtain more precise measurements of combustion energies of compounds containing the elements C, H, O and N, a combustion calorimeter in isoperibolic operation was designed, constructed and calibrated. The measurements made with this instrument show good precision; the results obtained for internal energy and the combustion enthalpy of succinic acid (solid sample) and for glycidol, glycidyl isopropyl ether, glycidyl butyrate and glycidyl methacrylate (liquid samples) are presented. The error percentage for the epsilon(calor) of the calorimetric system proposed was compared with a commercial calorimeter and published results in the literature. 收起