CHEM 121 Lecture Notes - Lecture 10: Thermal Energy, Calorimetry, Chemical Energy
Document Summary
Heat is the transfer of thermal energy between two bodies that are at different temperatures. Thermal energy is kinetic energy associated with the random motion of atoms and molecules. Temperature is the measure of the thermal energy. Chemical energy is potential energy stored within the bonds of chemical substances. System: what is releasing or gaining energy in the reaction. Energy out of the system to surroundings: - sign (releasing energy = exothermic) Energy into the system from surroundings: + sign (using energy = endothermic) Internal energy change = e nal - e initial = e. T = t nal - t initial. Heat capacity= the amount of heat in joules that takes to raise the temperature one degree. Speci c heat capacity= how well they store heat. Q(heat in j) = t( c) x speci c heat (j/ c x g) x mass (g) Heat lost by chemicals in reaction = heat gained by water in calorimeter.