Carbonate alkalinity
Encyclopedia
Carbonate alkalinity is a measure of the amount of carbonate
and bicarbonate
anions in solution
. Carbonate and bicarbonate anions contribute to alkalinity due to their basic nature, hence their ability to neutralize acid
. Mathematically, the carbonate anion concentration is counted twice due to its ability to neutralize two proton
s, while bicarbonate is counted once as it can neutralize one proton. Carbonate alkalinity is often the major component of a natural solution's total alkalinity
. It is an important factor in understanding large scale environmental interactions based on simple pH
and carbon dioxide
measurements.
Alkalinity is commonly expressed as mg/L CaCO3 because CaCO3 has an equivalent weight
of 50.
For water with a pH below 8.5, the CO32-
will be less than 1% of the HCO3-
.
Carbonate
In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, . The name may also mean an ester of carbonic acid, an organic compound containing the carbonate group C2....
and bicarbonate
Bicarbonate
In inorganic chemistry, bicarbonate is an intermediate form in the deprotonation of carbonic acid...
anions in solution
Solution
In chemistry, a solution is a homogeneous mixture composed of only one phase. In such a mixture, a solute is dissolved in another substance, known as a solvent. The solvent does the dissolving.- Types of solutions :...
. Carbonate and bicarbonate anions contribute to alkalinity due to their basic nature, hence their ability to neutralize acid
Acid
An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...
. Mathematically, the carbonate anion concentration is counted twice due to its ability to neutralize two proton
Proton
The proton is a subatomic particle with the symbol or and a positive electric charge of 1 elementary charge. One or more protons are present in the nucleus of each atom, along with neutrons. The number of protons in each atom is its atomic number....
s, while bicarbonate is counted once as it can neutralize one proton. Carbonate alkalinity is often the major component of a natural solution's total alkalinity
Alkalinity
Alkalinity or AT measures the ability of a solution to neutralize acids to the equivalence point of carbonate or bicarbonate. The alkalinity is equal to the stoichiometric sum of the bases in solution...
. It is an important factor in understanding large scale environmental interactions based on simple pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
and carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
measurements.
Alkalinity is commonly expressed as mg/L CaCO3 because CaCO3 has an equivalent weight
Equivalent weight
Equivalent weight is a term which has been used in several contexts in chemistry. In its most general usage, it is the mass of one equivalent, that is the mass of a given substance which will:...
of 50.
For water with a pH below 8.5, the CO32-
Carbonate
In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, . The name may also mean an ester of carbonic acid, an organic compound containing the carbonate group C2....
will be less than 1% of the HCO3-
Bicarbonate
In inorganic chemistry, bicarbonate is an intermediate form in the deprotonation of carbonic acid...
.