Monosodium phosphate also known as anhydrous monobasic sodium phosphate is a chemical compound

Chemical compound

A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...

 of sodium

Sodium

Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...

 with a phosphate

Phosphate

A phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...

 counterion. It is used as a laxative

Laxative

Laxatives are foods, compounds, or drugs taken to induce bowel movements or to loosen the stool, most often taken to treat constipation. Certain stimulant, lubricant, and saline laxatives are used to evacuate the colon for rectal and/or bowel examinations, and may be supplemented by enemas under...

 and, in combination with other sodium phosphates

Sodium phosphates

Sodium phosphate is a generic term for the salts of sodium hydroxide and phosphoric acid. They are:* sodium dihydrogen phosphate, commonly termed monosodium phosphate, , is also known as "sodium phosphate, monobasic"....

, as a pH buffer.

The pKa

PKA

PKA, pKa, or other similar variations may stand for:* pKa, the symbol for the acid dissociation constant at logarithmic scale* Protein kinase A, a class of cAMP-dependent enzymes* Pi Kappa Alpha, the North-American social fraternity...

 is 6.8-7.20 (depending on the physicochemical characteristics during pKa determination). The sodium chloride

Sodium chloride

Sodium chloride, also known as salt, common salt, table salt or halite, is an inorganic compound with the formula NaCl. Sodium chloride is the salt most responsible for the salinity of the ocean and of the extracellular fluid of many multicellular organisms...

equivalent value, or E-Value, is 0.49. It is soluble in 4.5 parts water. It is most commonly available as colorless crystals or a white powder. It is insoluble in alcohol. It is also formed when a sodium halide compound reacts with phosphoric acid.