Term	Page #*	Definition/Explanation
adiabatic system	36	A system that is thermally isolated from its surroundings.
bomb calorimeter	46	A device used to accurately measure U.
bond enthalpy	59	The molar enthalpy change accompanying the dissociation of a chemical bond.
calorimeter constant	46	The ratio of supplied heat to temperature change.
Classical thermodynamics	35	Thermodynamics developed during the nineteenth century that does not use the ideas of atoms and molecules.
closed system	36	A system that can exchange heat but not matter with its surroundings.
combustion	63	The reaction of a compound with oxygen.
condensation	54	The transition of a gas to a liquid. The reverse of vaporization.
conservation of energy	36	Energy cannot be created or destroyed.
constant-pressure heat capacity	48	The heat capacity for a system that is free to expand.
constant-volume heat capacity	48	The heat capacity for a system that cannot expand.
dissociation	59	The breaking of a chemical bond.
electron gain	58	The reverse of ionization, the gain of an electron on an atom (or ion).
electron gain enthalpy	58	The molar enthalpy change accompanying the addition of an electron to an atom (or ion).
endothermic	37	A process that absorbs heat from the surroundings.
endothermic compounds	67	They lie at a higher enthalpy than their component elements and have a positive standard enthalpy of formations.
energy	35	A property of matter that is the capacity to do work.
enthalpy	50	The enthalpy of a system, H, is defined as H=q.
enthalpy of fusion	54	The enthalpy per mole of molecules that accompanies fusion.
enthalpy of ionization	56	The molar enthaply change accompanying the removal of an electron from a gas-phase atom (or ion).
enthalpy of sublimation	55	The molar enthalpy change accompanying sublimation.
enthalpy of vaporization	52	The heat that must be supplied at constant pressure per mole of molecules that a vaporized.
exothermic	37	A process that releases heat into the surroundings.
exothermic compounds	67	They lie at a lower enthalpy than their component elements and have a negative standard enthalpy of formations.
expansion work	39	Work done when a system expands against an opposing pressure.
first ionization enthalpy	56	The molar enthaply change accompanying the removal of an electron from a gas-phase atom.
First Law of thermodynamics	45	The internal energy of an isolated system is constant.
freezing	54	The transition of a liquid to a solid. The reverse of fusion.
fusion	54	The transition from solid to liquid, also called melting. The reverse process is freezing.
heat	37	The transfer of energy as a result of a temperature difference between the system and the surroundings.
heat capacity	47	The constant of proportionality between q and T.
Hess's law	64	The standard enthalpy of a reaction is the sum of the standard enthalpies of the reactions into which the overall reaction may be divided.
internal energy	42	A method of keeping track of the energy of a system.
isolated system	36	A system that can neither exchange heat or matter with its surroundings.
Kirchoff's law	70	the relation between reaction enthalpies given by the equation: rH0'=rH+rCp•T
mean bond enthalpy	60	The average of a series of bond enthalpies for different compounds.
molar heat capacity	47	The heat capacity divided by the amount of substance.
open system	36	A system that can exchange matter with its surroundings.
reference state	66	The most stable state of an element under the prevailing conditions.
reversible	40	A change that can be reversed by an infinitesimal change in a parameter.
second ionization enthalpy	57	The molar enthaply change accompanying the removal of a second electron from a gas-phase or ion.
specific enthalpy	63	The heat released divided by the mass of the compound.
specific heat capacity	47	The heat capacity divided by the mass of the sample.
standard enthalpy of combustion	63	The standard change in enthalpy per mole of combustible substance.
standard enthalpy of formation	66	The standard enthalpy (per mole of substance) of a for its formation from its elements in their reference states.
standard reaction enthalpy	68	The difference between the standard enthalpies of formation of the reactants and the products, with each term weighted by the stoichiometric number in the chemical equation.
standard state	62	The state of a pure substance at exactly 1 bar.
state function	45	A physical property that depends only on the current state of the system and is independent of the path by which the state was reached.
statistical thermodynamics	35	The theory connecting bulk and atomic thermodynamic properties.
sublimation	55	The direct conversion of a solid to a vapor. The reverse process of vapor deposition.
surroundings	36	Everything outside of the system; this is where we make out observations.
system	36	The part of the world that we have interest in.
thermochemical equation	53	An equation that show the enthaply change that accompanies the conversion of an amount of reactant equal to its stoichiometric coefficient in the accompanying chemical equation.
thermochemistry	62	The study of the heat required or absorbed by chemical reactions.
thermodynamics	35	The study of the transformation of energy.
vapor deposition	55	The direct conversion of a vapor to a solid. The reverse process of sublimation.
work	37	A transfer if energy that can be used to change the height of a weight somewhere in the surroundings.

This page was made by Erik Epp.