Sulfuric Acid
Definition and meaning of Sulfuric Acid in chemistry.
Sulfuric acid is a highly corrosive, dense, oily mineral acid with the chemical formula H2SO4. It is widely considered one of the most important industrial chemicals globally, heavily utilized in the manufacture of agricultural fertilizers, chemical explosives, and lead-acid storage batteries.
In more detail
Sulfuric acid acts as a strong diprotic acid, meaning it can donate two protons (H+) in an aqueous solution, with the first molecular dissociation step proceeding to virtual completion. It acts as a remarkably powerful dehydrating agent, capable of stripping the elements of water directly from organic materials like simple sugars, carbohydrates, and paper, leaving behind elemental carbon in violently exothermic chemical reactions. The primary industrial synthesis of sulfuric acid is achieved via the contact process, which involves catalytically oxidizing sulfur dioxide to sulfur trioxide using a solid vanadium(V) oxide catalyst, followed by carefully controlled absorption into existing concentrated sulfuric acid to form fuming oleum. Concentrated sulfuric acid also functions as a potent oxidizing agent, particularly at elevated temperatures where it can chemically react directly with non-metals like solid carbon and sulfur. Its widespread chemical application in producing highly acidic phosphoric acid for agricultural phosphate fertilizers continuously accounts for the largest share of its massive global annual consumption.
Key facts
| Field | Inorganic Chemistry |
|---|---|
| Formula | H2SO4 |
| Molar mass | 98.08 g/mol |
| Appearance | Clear, colorless liquid |
| Boiling point | 337 °C |
Inside a standard 12-volt automotive car battery, a 30% to 50% aqueous solution of sulfuric acid serves as the liquid electrolyte, facilitating the reversible chemical reactions between the lead and lead dioxide plates.
Frequently asked questions
Why must pure water never be added directly to concentrated sulfuric acid?
The aqueous dilution of concentrated sulfuric acid is extremely exothermic. Adding water directly to the acid causes immediate localized boiling and violent splattering of the hot corrosive liquid; instead, the denser acid must be poured slowly into water while continuously stirring.
What happens chemically when concentrated sulfuric acid reacts with ordinary table sugar?
Sulfuric acid violently dehydrates the solid sucrose, literally stripping away bound hydrogen and oxygen atoms as expanding water vapor. The reaction generates intense heat and leaves behind a rapidly growing column of black, porous elemental carbon.