2KCl

2KCl denotes two formula units of potassium chloride in a chemical equation. Potassium chloride (KCl) is an ionic salt composed of potassium ions (K+) and chloride ions (Cl−) arranged in a crystal lattice. In solid form there are no discrete KCl molecules; the 2 indicates two formula units, not a separate chemical species.

Potassium chloride is a white, odorless crystalline solid that is highly soluble in water. Its melting point is about 770°C, and it decomposes at higher temperatures. In aqueous solution, KCl dissociates into K+ and Cl− ions. It has a density around 1.98 g/cm3 and a solubility of approximately 34 g per 100 g of water at 20°C.

Occurrence and production: KCl occurs naturally as the mineral sylvite and is a major source of potassium for fertilizers. Industrial production typically involves mining sylvite or brine processing to concentrate potassium salts, followed by purification. Common laboratory synthesis routes include neutralization of potassium hydroxide with hydrochloric acid to yield KCl and water.

Uses: The principal use of potassium chloride is as a source of potassium in agriculture, where it serves as fertilizer. It is also used in food processing as a salt substitute and in medicine as an electrolyte in intravenous solutions, where appropriate. In chemistry laboratories, KCl is a common, inexpensive salt used in various reactions and as a calibration or buffering component in some systems.

Safety: Potassium chloride is relatively low in toxicity but can disrupt cardiac function at high oral or intravenous doses. Caution is required for individuals with impaired kidney function or those on potassium-restrictive diets, and it should be handled according to standard chemical safety practices.