CsHSO4

CsHSO4, or cesium hydrogen sulfate, is an inorganic salt composed of cesium cations (Cs+) and bisulfate anions (HSO4−). It is the cesium salt of sulfuric acid’s bisulfate and belongs to the family of alkali metal bisulfates. In the solid state it forms colorless to white crystals and is soluble in water, giving an acidic solution.

Preparation and structure: CsHSO4 can be prepared by partial neutralization of Cs2SO4 with H2SO4 or by neutralizing CsOH with H2SO4, followed by crystallization. The compound crystallizes as a solid salt; its crystal structure and properties can vary with temperature.

Properties and behavior: The molar mass of CsHSO4 is about 230.0 g/mol. In aqueous solution, HSO4− contributes acidity; the solution acidity is enhanced by the bisulfate anion. The solid exhibits temperature-dependent phase transitions; at higher temperatures it shows increased proton conductivity, which has attracted interest for solid-state electrochemical applications.

Applications: CsHSO4 has been studied as a solid acid catalyst for organic reactions, such as esterifications and dehydrations, and as a proton-conducting electrolyte in solid-state devices and fuel-cell research.

Safety and handling: CsHSO4 is a corrosive salt. It should be handled with appropriate personal protective equipment, including gloves and eye protection, and kept away from skin and eyes. It should be stored in a dry, labeled container and disposed of according to local regulations.