only slightly; found at relatively low pressure and high temperatures. Also called vapor. See Ideal
gas.
Gas constant (R)
Gas constant (R)
A proportionality constant that appears in the ideal gas law, PV = nRT. Its value depends upon
the units of pressure, temperature, and volume used in a given situation.
Geiger counter
Geiger counter
An instrument used to measure radioactivity.Gibbs free energy (G)
Gibbs free energy (G)
The energy of a system available to do work. The change in Gibbs free energy, ∆G, is determined
for a given reaction from the equation ∆G = ∆H – T∆S. ∆G is used to predict the spontaneity of a
reaction: A negative ∆G denotes a spontaneous reaction, while positive ∆G denotes a
nonspontaneous reaction.
Graham’s law
Graham’s law
The law stating that the rate of effusion or diffusion of a gas is inversely proportional to the
square root of the gas’s molecular weight.
Gram-equivalent weight
Gram-equivalent weight
The amount of a compound that contains 1 mole of reacting capacity when fully dissociated.
One GEW equals the molecular weight divided by the reactive capacity per formula unit.