Sulfuric acid is a highly corrosive strong mineral acid, generally transparent to yellowish, at any concentration can be mixed with water and exothermic. In some cases, sulfuric acid may also be dyed dark brown in the process of industrial manufacturing to increase the vigilance of the people. As two-yuan acid, sulfuric acid has different properties at different concentrations, the corrosive properties of different substances, such as metals, biological tissues, and even rocks, are all rooted in its strong acidity and its strong dehydration (chemical properties), water absorption (physical properties) and oxidation at high concentrations. Sulfuric acid can cause a lot of damage to the flesh, because in addition to the acid hydrolysis reaction to decompose protein and fat caused by chemical burns, but also with carbohydrate dehydration and caused two flame burns; if you accidentally eyes, it will damage the retina caused permanent blindness. Therefore, in the use of adequate safety measures should be done. Sulfuric acid is easily hygroscopic and absorbs water vapor from the air.