Chemistry Reference
In-Depth Information
CHEMISTRY
G
D
ENERAL
EFINITIONS
Ion
An atom or group of atoms (molecule) with an electrical charge.
Positively charged ions are called
cations
while negatively
charged ions are called
anions
.
Acid
A compound containing hydrogen that dissolves in water to produce
hydrogen ions. Hydrogen ions are positively charged.
Base
A compound that will react with (
) hydrogen ions to
produce water. It is the opposite of an acid. A water-soluble base
is an
neutralize
alkali
.
Salt
Substance in addition to water that is produced from the reaction of
an acid with a base.
pH
A measurement of hydrogen ion concentration (
) in water.
Pure water has a pH of 7. Acids have a pH less than 7 while the
pH of bases is above 7.
acidity
All chemicals, whether inorganic or organic, are either acidic, basic, or
neutral. An example of an inorganic acid is sulfuric acid used in automobile
batteries, while the acetic acid found in vinegar is an organic acid. Ammonia
found in many household cleaners is a base, as are sodium carbonate and
sodium hydroxide (lye). Sodium chloride (common salt) is an example of a
salt because it is produced by the
of hydrochloric acid with
sodium hydroxide. A solution of table sugar in water is neutral (pH 7) because
it does not contain hydrogen ions nor does it react with bases to produce
water.
Control of pH is of critical importance in many industrial operations such
as water purification, food and drug preservation, and agriculture.
neutralization
