The compound with the chemical formula H₂SO₄ that is widely used to make fertilizers is sulfuric acid.
Sulfuric acid is a strong mineral acid composed of hydrogen, sulfur, and oxygen. It is usually colorless when pure, but commercial samples can appear darker because of impurities. The compound reacts strongly with water and is highly corrosive, so concentrated sulfuric acid must be handled with specialized safety equipment.
A major industrial use is producing phosphate fertilizers. Sulfuric acid reacts with phosphate rock to help manufacture phosphoric acid and superphosphate materials. It is also used in petroleum refining, chemical synthesis, metal processing, and some lead-acid batteries.
Sulfuric acid should not be confused with sulfurous acid, which has the formula H₂SO₃ and is associated with sulfur dioxide dissolved in water. Concentrated sulfuric acid is also a powerful dehydrating agent, meaning it can remove water from many substances.