The ammonium bisulfite solution is acidic. Pure ammonium bisulfite is white or light yellow diamond-shaped crystals. Sublimation at 150°C. Slightly sulfur dioxide. Easily absorb moisture in the air. It is very soluble in water, with a solubility of 2679 in 100ml of water at 10°C and a very high solubility in 6209 at 60°C. Soluble in ethanol. It decomposes evenly in acid and heat, releasing sulfur dioxide. Prolonged exposure to the air is easily oxidized to ammonium sulfate. It has a strong reducibility. The solution is light brown to light brown with an odor of sulfur dioxide. The relative density (cs096 solution) is 1.3. It can react with acids and bases. It is easily oxidized in the air and decomposes under heat to release sulfur dioxide.

It is prepared by absorbing the sulfur dioxide contained in the refined sulfur dioxide raw material gas or tail gas in the production of sulfuric acid by ammonia water, and then performing concentration, cooling, crystallization and centrifugal separation.

Sulfuric acid (chemical formula: H2SO4) is an important strong acid containing sulfuric acid. Anhydrous sulfuric acid is a colorless oily liquid that crystallizes at 10.36°C.

Usually the tower method and contact method are used in various aqueous solutions of different concentrations. The former is crude dilute sulfuric acid with a mass fraction of about 75%, while the latter is concentrated sulfuric acid with a mass fraction of 98.3%, a boiling point of 338°C, and a relative density of 1.84.

Sulfuric acid is one of the highly active binary inorganic strong acids and can react with most metals. High-concentration sulfuric acid has a strong water absorption rate, and can be used as a dehydrating agent, carbonized wood, paper, cotton and linen fabrics, biological skin and meat and other carbohydrate-containing substances. When mixed with water, it releases a lot of heat energy. It is highly corrosive and oxidizing, so it should be used with caution. As an important industrial raw material, it can be used to make fertilizers, medicines, explosives, pigments, detergents, batteries, etc. It is also widely used in oil refining, metal smelting, dyes and other industries. Often used as a chemical reagent, it can be used as a dehydrating agent and a sulfonating agent in organic synthesis.