http://www.ck12.org Chapter 27. Glossary
enthalpy
A thermodynamic function 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. The symbol for enthalpy is
H.enthalpy of reaction
When a mole of matter is altered by a chemical reaction under standard conditions, a change of enthalpy takes
place.entropy
A thermodynamic function that describes the number of arrangements that are available to a system existing
in a given state. A measure of randomness or disorder. The symbol of entropy is S.enzyme
Catalyzes biochemical reactions.equilibrium constant
Relates the concentrations of materials on both sides of the reaction arrow at equilibrium.equilibrium expression
Can be used to describe changes for a chemical reaction.equivalence point
The point in a neutralization reaction where the number of moles of hydrogen ions is equal to the number of
moles of hydroxide ions.ester
Formed from a reaction between an alcohol and a carboxylic acid.estimate
As used in measurement, is the process of referencing a physical quantity in terms of a calibration or reference
point.ether
The ether functional group consists of an oxygen atom which forms single bonds with two carbon atoms.evaporation
The process whereby atoms or molecules in a liquid state (or solid state, if the substance sublimes) gain
sufficient energy to enter the gaseous state. This can be used as a technique to separate the liquid component
of a homogeneous mixture from its dissolved solids.exothermic reaction
A reaction that releases heat during the course of the reaction.extensive properties
Properties that depend on the amount of a substance that is present. Examples include mass, volume, and
length.