Calorimetry Definition: Calorimetry is the accurate and precise measurement of heat flow for chemical and physical processes. It operates under the law of conservation of energy (what is that?) Heat loss = Heat gained A device used to measure the absorption or release of this heat is called Calorimeter Watch a video lecture for an example.

Types of Calorimeters: Open to page 511 Constant-Pressure Calorimeter (simple calorimeter) Because it is open to a constant atmospheric pressure Heat content of a system at constant pressure is know as Enthalpy (H) of the system Change in Enthalpy (ΔH) measures the amount of heat release or absorbed by a reaction at constant pressure. q= ΔH

MEASURING ENTHALPY CHANGE Minimizing Heat loss in a simple calorimeter Convection Radiation Conduction MEASURING ENTHALPY CHANGE q= CmΔT qsys = -qsurr -qsys = qsurr qsys = ΔH = -qsurr = - m. C. ΔT ΔH = - m. C. ΔT ΔH = negative = exothermic ΔH = positive = endothermic Discuss system and surroundings: Demo vinegar and Baking soda. Simulation Phet. Sources of energy

Types of Calorimeters: Open to page 512 Constant-Volume Calorimeter (Bomb calorimeter) Bomb calorimeter is an insulated device containing a sealed vessel used to measure the heat released during a combustion reaction. It is the most reliable device for measuring specific heat of a substance It is performed at constant volume of oxygen at high pressure.

Thermochemical equation A chemical equation that includes the enthalpy change (ΔH)