Sulfuric acid, the most important oxygen-containing acid of sulfur. Anhydrous sulfuric acid is a colorless oily liquid, which crystallizes at 10.36 ℃. It is usually made of various aqueous solutions of different concentrations by tower method and contact method. The former is crude dilute sulfuric acid with a mass fraction of about 75%; the latter is pure concentrated sulfuric acid with a mass fraction of 98.3%, boiling point of 338 ℃, and relative density of 1.84.

      Sulfuric acid is the most active binary inorganic strong acid, which can react with many metals. High concentration sulfuric acid has strong water absorption, which can be used as dehydrating agent, carbonizing wood, paper, cotton and linen fabric, biological skin and other carbohydrate containing substances. When mixed with water, a lot of heat energy will also be released. It has strong corrosiveness and oxidation, so it should be used carefully. It is an important industrial raw material, which can be used to manufacture fertilizer, medicine, explosives, pigments, detergents, batteries, etc. it is also widely used in the purification of petroleum, metal smelting, dye and other industries. It is often used as a chemical reagent and as a dehydrating agent and sulfonating agent in organic synthesis. Colorless viscous liquid, strong corrosive, irritant odor, soluble in water, produce dilute sulfuric acid.