27.5. E http://www.ck12.org
The point during a titration experiment when the indicator changes color.
endothermic
The condition of a process where heat is absorbed by the system from the surroundings.
energy
The capacity to do work or to produce heat.
enthalpy
The heat content of a system at constant pressure.
entropy
A measure of the degree of randomness or disorder of a system.
enzyme
A protein that acts as a biological catalyst.
equilibrium constant (Keq)
The ratio of the mathematical product of the concentrations of the products of a reaction to the mathematical
product of the concentrations of the reactants of the reaction, with each concentration raised to the power of
its coefficient in the balanced chemical equation.
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.
error
The difference between the experimental values and accepted values of a measurement.
ester
An organic compound that is a derivative of a carboxylic acid in which the hydrogen atom of the hydroxyl
group has been replaced with an alkyl group.
esterification
A reaction in which an ester is formed from an alcohol and a carboxylic acid.
ether
An organic compound in which two hydrocarbon groups are bonded to the same atom of oxygen.
evaporation
The conversion of a liquid to its vapor below the boiling temperature of the liquid.
excess reactant (reagent)
The reactant that is initially present in a greater amount than will eventually be reacted; some excess reactant
is left over after the reaction is complete.
excited state
A state of an atom where its potential energy is higher than the ground state.
exothermic
A condition of a process where heat is released by the system into the surroundings.
experimental value
The quantitative value of a measurement obtained during an experiment.
extensive property
Property that depends on the amount of matter in a sample.