Chapter 17
Thermochemical Equation
A chemical equation that includes the enthalpy change.
Endothermic Process
A process that absorbs heat from the surroundings.
Exothermic Process
A process that releases heat to its surroundings.
Surroundings
Everything else in the universe.
Heat
Represented by q, the energy transfers from one object to another because of a temperature difference between them.
Hess's Law of Heat Summation
States that if you add two or more thermochemical equations to give a final equation, then you can also add the heats of reaction to give the final heat of reaction.
Law of Conservation of Energy
States that in any chemical or physical process, energy is neither created nor destroyed.
Molar Heat of Vaporization
The amount of heat necessary to vaporize one mole of a given liquid.
Heat Capacity
The amount of heat needed to increase the temperature of an object exactly one degree Celsius.
Molar Heat of Condensation
The amount of heat released when 1 mol of vapor condenses at the normal boiling point.
Chemical Potential Energy
The energy stored in the chemical bonds of a substance.
Molar Heat of Solution
The enthalpy change caused by dissolution of one mole of substance.
Heat of Reaction
The enthalpy change for the chemical equation exactly as it is written.
Molar Heat of Fusion
The heat absorbed by one mole of a solid substance as it melts to a liquid at a constant temperature.
Enthalpy
The heat content of a system at constant pressure is the same as property called the enthalpy of the system.
Molar Heat of Solidification
The heat lost when one mole of a liquid solidifies at a constant temperature.
Heat of Combustion
The heat of reaction for the complete burning of one mole of a substance.
Calorimeter
The insulated device used to measure the absorption or release of heat in chemical or physical processes.
System
The part of the universe on which you focus your attention.
Calorimetry
The precise measurement of the heat flow into or out of a system for chemical and physical processes.
Specific Heat
The specific heat capacity of a substance is the amount of heat it takes to raise the temperature of 1 gram of the substance one degree Celsius.
Thermochemistry
The study of energy changes that occur during chemical reactions and changes in state.
Standard Heat of Formation
the change in enthalpy that accompanies the formation of one mole of a compound from its elements with all substances in their standard states at 25 degrees Celsius.
