Chemical Properties
Also known as acid potassium sulfate and potassium acid sulfate, KHS04 is water soluble, white deliquescent crystals,which melt at 214°C. It is used in wine making, fertilizer manufacture, and as a flux and food preservative.
Uses
As flux in analysis of ores and siliceous Compounds.
General Description
POTASSIUM HYDROGEN SULFATE(7646-93-7) is a colorless crystalline solid with a sulfur odor. POTASSIUM HYDROGEN SULFATE(7646-93-7) may cause illness from ingestion. If heated to high temperatures POTASSIUM HYDROGEN SULFATE(7646-93-7) may emit toxic fumes. POTASSIUM HYDROGEN SULFATE(7646-93-7) is used to make fertilizers and wine.
Reactivity Profile
Acidic salts, such as POTASSIUM HYDROGEN SULFATE, are generally soluble in water. The resulting solutions contain moderate concentrations of hydrogen ions and have pH's of less than 7.0. They react as acids to neutralize bases. These neutralizations generate heat, but less or far less than is generated by neutralization of inorganic acids, inorganic oxoacids, and carboxylic acid. They usually do not react as either oxidizing agents or reducing agents but such behavior is not impossible. Many of these compounds catalyze organic reactions.
Air & Water Reactions
Fused salt is deliquescent, Soluble in water, yielding a corrosive acidic solution.
Health Hazard
TOXIC; inhalation, ingestion or skin contact with material may cause severe injury or death. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.
Fire Hazard
Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated.
Application
Potassium bisulfate may be used:
As a catalyst for the preparation of butyl paraben from p-hydroxybenzoic acid and n-butyl alcohol.
As a promoter for the synthesis of 3,4-dihydropyrimidin-2(1H)-one derivatives via Biginelli reaction in ethylene glycol.
As an acid catalyst for the synthesis of ethyl tert-butyl ether (ETBE) from ethanol and tert-butyl alcohol via reactive distillation.
As a dehydrating agent for the synthesis of pyruvic acid from tartaric acid.
Preparation
Potassium bisulfate is typically made by heating potassium sulfate (K2SO4) with sulfuric acid. The acid provides the hydrogen needed to convert the salt (K2SO4) to the corresponding acid salt (KHSO4).
Purification Methods
Crystallise it from H2O (1mL/g) between 100o and 0o. It is also formed when a warm solution of K2SO4 in conc H2SO4 is cooled down.
