Potassium hydrogen phosphate Formula - Potassium Hydrogen Phosphate Uses, Properties, Structure and Formula

Potassium hydrogen phosphate is an inorganic chemical that belongs to the family of potassium phosphates. It is more commonly known as dipotassium phosphate or potassium phosphate dibasic.

Formula and structure: The chemical formula of potassium hydrogen phosphate is K₂HPO₄. Its molecular formula is HK₂O₄P, and its molar mass is 174.2 g/mol. It is the dipotassium salt of phosphoric acid (H₃PO₄, which has three acidic protons). It consists of two potassium cations (K⁺) and one phosphate anion (HPO₄^2-), in which the phosphorous atom is attached to one hydroxyl group, one double bonded oxygen atom, and two single bonded oxygen atoms.

Preparation: Potassium hydrogen phosphate is prepared by the partial neutralization of phosphoric acid (H₃PO₄) with potassium hydroxide (KOH) or potassium carbonate (K₂CO₃).

2 KOH + H₃PO₄ → K₂HPO₄ + 2 H₂O

Physical properties: Potassium hydrogen phosphate exists as an odorless white crystalline solid. It has a density of 2.44 g/mL and decomposes above 465 °C. It is a deliquescent solid (absorbs enough water to turn into solution).

Chemical properties: Potassium hydrogen phosphate is highly water soluble and sparingly soluble in alcohols. It is a hygroscopic and deliquescent compound, and dissolves in water to give a moderately basic solution. It is a stable compound but decomposes when heated to high temperatures.

Uses: Potassium hydrogen phosphate is mainly used as a fertilizer, corrosion inhibitor and buffering agent. It is also used as a food additive, in mineral supplements, in non-dairy creamers, and in pharmaceuticals. It is used as an electrolyte source and has radioprotective activity. Other applications include paper processing, yeast nutrient, agar for culturing bacteria and chemical reagent.

Health effects/safety hazards: Potassium hydrogen phosphate can irritate the skin, eyes and respiratory tract upon contact or inhalation. It is not toxic and is considered safe as a food additive. However, excessive consumption of potassium salts can cause imbalance in the electrolyte levels, resulting in several symptoms such as nausea, vomiting, diarrhea, abdominal discomfort, and limited absorption of necessary nutrients.