Sulfuric Acid Formula - Sulfuric Acid Uses, Properties, Structure and Formula

Sulfuric acid is one of the most important mineral acids with a wide range of applications.

Formula and structure: The chemical formula of sulfuric acid is H₂SO₄ and its molecular weight is 98.079 g/mol. Its chemical structure is shown below. The sulfur atom is bound to two oxygen atoms through double bonds, and two hydroxyl groups (OH) through single bonds. It is a diprotic acid, as it can release two protons.

Occurrence: Sulfuric acid is formed naturally by oxidation of sulfide minerals in rocks. Dilute sulfuric acid is also formed in the atmosphere by oxidation of sulfur dioxide (from burning of fuels) in the presence of moisture, eventually precipitating as 'acid rain'.

Preparation: Sulfuric acid is prepared commercially by the reaction of water with sulfur trioxide.

SO₃ + H₂O → H₂SO₄

Sulfur trioxide (SO₃) is formed by the reaction of sulfur dioxide and oxygen catalyzed by vanadium oxide, by the contact process or the chamber process.

Physical properties: H₂SO₄ is a colorless or slightly yellow viscous liquid with a pungent odor. It has a density of 1.84 g/mL, boiling point of 337 °C, and melting point of 10 °C. "Concentrated" sulfuric acid is 98% in water, and is the most stable form. Many other concentrations, with different names, are available for various purposes. Battery acid is 29–32%, chamber acid is 62-70%, and tower acid is 78-80%.

Chemical properties: Sulfuric acid is a very strong, diprotic acid. It is hygroscopic and readily absorbs moisture from air. It is a powerful oxidizing agent and reacts with many metals at high temperatures. Concentrated H₂SO₄ is also a strong dehydrating agent. Addition of water to concentrated sulfuric acid is a very exothermic reaction and can lead to explosions.

Uses: Sulfuric acid has many uses in different industries, such as mineral processing, petroleum refining, fertilizer production, wastewater processing, etc. It is also used in the production of cleaning agents, dyes, pigments, drugs, detergents, and explosives. It is commonly used as the electrolyte in lead-acid batteries.

Health hazards/ health effects: Concentrated H₂SO₄ is highly corrosive, and can severely damage tissues upon contact. Being a strong acid, oxidizer, corrosive agent and dehydrating agent, it is more dangerous than the other mineral acids. It causes severe chemical burns upon skin contact. Contact with eyes can lead to permanent damage and blindness. Ingestion of the acid can even lead to death.