chemistry 17.2

what is calorimetry?

Measurement of heat flow into or out of a system during chemical/physical processes.

what is Calorimeter?

it is an Insulated device used to measure heat absorption or release

what is constant-pressure calorimeter set up?

Uses nested foam cups as insulation, open to constant atmospheric pressure.

• System: Reacting chemicals dissolved in water.

• Surroundings: The water itself.

Constant-Volume Calorimeter (Bomb Calorimeter)?

Measures heat from combustion at constant volume; sample burns in a sealed, oxygen-filled chamber surrounded by water.

what is a Thermochemical Equation?

A balanced chemical equation that includes physical states of all reactants/products and the enthalpy change (ΔH).

Heat Placement in Exothermic process

Heat released is written on the product side (or as a negative ΔH)

heat placement in endothermic process

Heat absorbed is written on the reactant side (or as a positive ΔH).

what is the Standard Conditions for Heat of Reaction (ΔH∘)?

Measured at 101.3 kPa1 (atm) and 25∘C with reactants/products in their standard physical states.

Energy Shift Exothermic

Reactants have higher potential energy than products; excess energy escapes as heat.

Energy Shift Endothermic

Products have higher potential energy than reactants; heat is absorbed and stored in bonds.

what is Stoichiometry of Heat

Heat absorbed or released scales directly with the number of moles and depends on physical states.