Alkali salts or base salts are salts that are the product of incomplete
neutralization of a
strong base
In chemistry, there are three definitions in common use of the word "base": '' Arrhenius bases'', '' Brønsted bases'', and '' Lewis bases''. All definitions agree that bases are substances that react with acids, as originally proposed by G. ...
and a
weak acid.
Rather than being neutral (as some other
salts), alkali salts are
bases as their name suggests. What makes these compounds basic is that the conjugate base from the weak acid hydrolyzes to form a basic solution. In
sodium carbonate, for example, the
carbonate
A carbonate is a salt of carbonic acid, (), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word "carbonate" may also refer to a carbonate ester, an organic compound containing the carbonate group ...
from the
carbonic acid
Carbonic acid is a chemical compound with the chemical formula . The molecule rapidly converts to water and carbon dioxide in the presence of water. However, in the absence of water, it is quite stable at room temperature. The interconversion ...
hydrolyzes to form a basic solution. The chloride from the
hydrochloric acid
Hydrochloric acid, also known as muriatic acid or spirits of salt, is an aqueous solution of hydrogen chloride (HCl). It is a colorless solution with a distinctive pungency, pungent smell. It is classified as a acid strength, strong acid. It is ...
in
sodium chloride
Sodium chloride , commonly known as Salt#Edible salt, edible salt, is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chloride ions. It is transparent or translucent, brittle, hygroscopic, and occurs a ...
does not hydrolyze, though, so sodium chloride is not basic.
The difference between a basic salt and an alkali is that an alkali is the soluble hydroxide compound of an alkali metal or an alkaline earth metal. A basic salt is any salt that hydrolyzes to form a basic solution.
Another definition of a basic salt would be a salt that contains amounts of both hydroxide and other anions.
White lead is an example. It is basic lead carbonate, or lead carbonate hydroxide.
These materials are known for their high levels of dissolution in polar solvents.
These salts are insoluble and are obtained through
precipitation reactions.
Examples
*
Sodium carbonate
*
Sodium acetate
*
Potassium cyanide
*
Sodium sulfide
*
Sodium bicarbonate
Sodium bicarbonate ( IUPAC name: sodium hydrogencarbonate), commonly known as baking soda or bicarbonate of soda (or simply “bicarb” especially in the UK) is a chemical compound with the formula NaHCO3. It is a salt composed of a sodium cat ...
*
Sodium hydroxide
Alkaline salts
'Alkaline salts' are often the major component of alkaline
dishwasher detergent powders.
These salts may include:
*
alkali metasilicates
*
alkali metal hydroxides
*
Sodium carbonate
*
Sodium Bicarbonate
Sodium bicarbonate ( IUPAC name: sodium hydrogencarbonate), commonly known as baking soda or bicarbonate of soda (or simply “bicarb” especially in the UK) is a chemical compound with the formula NaHCO3. It is a salt composed of a sodium cat ...
Examples of other strongly alkaline salts, include:
*
Sodium percarbonate
*
Sodium persilicate (?)
*
Potassium metabisulfite
See also
*
Alkali
*
Acid salt
References
{{reflist
Salts