6.4.A—Calculate the heat q absorbed or released by a system undergoing heating/ cooling based on the amount of the…

Calculate the heat q absorbed or released by a system undergoing heating/ cooling based on the amount of the substance, the heat capacity, and the change in temperature.

• The heating of a cool body by a warmer body is an important form of energy transfer between two systems. The amount of heat transferred between two bodies may be quantified by the heat transfer equation: EQN: q = mcΔT. Calorimetry experiments are used to measure the transfer of heat.
• The first law of thermodynamics states that energy is conserved in chemical and physical processes.
• The transfer of a given amount of thermal energy will not produce the same temperature change in equal masses of matter with differing specific heat capacities.
• Heating a system increases the energy of the system, while cooling a system decreases the energy of the system.
• The specific heat capacity of a substance and the molar heat capacity are both used in energy calculations.
• Chemical systems change their energy through three main processes: heating/cooling, phase transitions, and chemical reactions.
• In calorimetry experiments involving dissolution, temperature changes of the mixture within the calorimeter can be used to determine the direction of energy flow. If the temperature of the mixture increases, thermal energy is released by the dissolution process (exothermic). If the temperature of the mixture decreases, thermal energy is absorbed by the dissolution process (endothermic). Thermochemistry UNIT 6