NaHSO4

Sodium hydrogen sulfate, commonly known as sodium bisulfate, has the chemical formula NaHSO4. It is the sodium salt of the bisulfate ion and is typically encountered as a white crystalline solid with a molecular weight of about 120.1 g/mol. It is highly soluble in water, and in aqueous solution it forms an acidic medium due to the HSO4−/SO4^2− system.

In solution, NaHSO4 behaves as a moderately strong acid; the pH of its aqueous solutions is usually around 1 to 2. When heated, it decomposes to form sodium sulfate and sulfuric acid, with the simplified reaction 2 NaHSO4 → Na2SO4 + H2SO4 evident at elevated temperatures.

Preparation of NaHSO4 is usually achieved by partial neutralization of sulfuric acid with sodium hydroxide, which yields NaHSO4 and water rather than complete neutralization to Na2SO4. It can also be produced by reacting sulfuric acid with sodium bicarbonate under controlled conditions.

The compound is used in a variety of applications. It serves as an acidity regulator and pH control agent in pools, cleaning products, and some food-processing operations. It is also employed as a laboratory reagent and, in certain industrial processes, as a source of acidic sulfate species for chemical synthesis and processing.

Safety and handling: NaHSO4 is corrosive and can cause skin and eye irritation upon contact; inhalation of dust can irritate the respiratory tract. It should be handled with appropriate protective equipment, stored away from bases and incompatible materials, and kept in a cool, dry place. Proper ventilation and containment procedures are recommended when working with the solid or its solutions.