tripotassium

Tripotassium refers to a class of chemical compounds that contain three potassium ions (K+) for each formula unit. In these compounds, potassium is always in the +1 oxidation state, and the three K+ ions balance a negatively charged anion or polyatomic ion with a total charge of −3. The term is a descriptor rather than a distinct element.

Common examples include tripotassium phosphate, K3PO4, a white, highly soluble salt used as a buffering agent and in various industrial applications; and tripotassium citrate, K3C6H5O7, the potassium salt of citric acid used as a buffering agent and dietary potassium supplement. These compounds illustrate how three potassium ions pair with a trivalent anion or trivalent polyatomic ion to form stable solids.

Synthesis of tripotassium salts typically involves neutralization reactions between a triprotic acid and potassium hydroxide or a potassium-containing base. For example, phosphoric acid reacts with potassium hydroxide to yield K3PO4, while citric acid reacts with potassium hydroxide to yield K3C6H5O7. The resulting salts are generally white, odorless solids that dissolve readily in water.

Uses and occurrences vary by specific salt. Tripotassium phosphate is employed in industrial processes, detergents, and as a chemical reagent, while tripotassium citrate serves as a food additive and dietary supplement, and as a buffering agent in certain pharmaceutical formulations. Safety considerations for tripotassium salts include typical handling precautions for inorganic potassium salts: they are caustic in concentrated form and can cause irritation; they should be stored dry and used with appropriate protective equipment.