Thermochemistry

Each list begins with basic conceptual vocabulary you need to know for MCAT questions and proceeds to advanced terms that might appear in context in MCAT passages. The terms are links to Wikipedia articles.
Thermochemistry
Thermochemistry is the study of the heat evolved or absorbed in chemical reactions.
Enthalpy
The enthalpy or heat content is a quotient or description of thermodynamic potential of a system equivalent to the sum of the internal energy of the system plus the product of its volume multiplied by the pressure exerted on it by its surroundings.
Heat of combustion
The heat of combustion is the energy released when a compound undergoes complete combustion with oxygen.
Exothermic
Exothermic describes a process or reaction that releases energy in the form of heat.
Endothermic
Endothermic describes a process or reaction that absorbs energy in the form of heat.
Calorimeter
A calorimeter is a device used for measuring the heat of chemical reactions or physical changes as well as heat capacity.
Standard conditions for temperature and pressure
Standard temperature and pressure is a standard set of conditions for experimental measurements, to enable comparisons to be made between sets of data.
Hess's law
Developed through conceptualizing cyclic reaction processes in which the return path is different than the forward path, Hess's Law of Heat Summation is used to predict the enthalpy change regardless of the path through which it is to be determined.
Reaction calorimeter
A reaction calorimeter is an instrument that enables the energy being released or absorbed by a reaction to be measured.
Calorimetry
Calorimetry is the science of measuring the heat of chemical reactions or physical changes.
Bond dissociation energy
Bond dissociation energy is defined as the standard enthalpy change when a bond is cleaved by homolysis, with reactants and products of the homolysis reaction at 0K (absolute zero).
Standard enthalpy of Combustion
The standard enthalpy of combustion is the change in enthalpy of the total reacting system when one mole of a substance completely reacts with oxygen, and is observed at 298K and 1 atmospheric pressure
Standard enthalpy of formation
The standard enthalpy of formation of a compound is the change of enthalpy that accompanies forming 1 mole of a substance in its standard state from its constituent elements in their standard states
Born-Haber cycle
The Born-Haber Cycle is an approach to analyzing reaction energies involving the formation of an ionic compound from the reaction of a group I or group II metal with a non-metal.
Standard state
The standard state of a material is its state at 1 bar (100 kilopascals exactly).
Lattice energy
The lattice energy of an ionic solid is a measure of the strength of bonds in that ionic compound, equivalent to the amount of energy required to separate a solid ionic compound into gaseous ions.
Standard enthalpy change of reaction
The standard enthalpy change of reaction is the enthalpy change that occurs in a system when one mole of matter is transformed by a chemical reaction under standard conditions.
Enthalpy of atomization
The enthalpy of atomization is the enthalpy change that accompanies the total separation of all atoms in a chemical substance
Isenthalpic process
An isenthalpic process is one that proceeds without any change in enthalpy (also known as a throttling process).
Isodesmic reaction
An isodesmic reaction is a chemical reaction in which the type of chemical bonds broken in the reactant are the same as the type of bonds formed in the reaction product.




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