An Overview Of Sulphuric Acid

Sulphuric acid is a mineral acid with sulphur, hydrogen, and oxygen elements. It is a colourless, odourless, viscous, and miscible liquid with water. Because of its great affinity for water vapour, pure sulphuric acid cannot be found naturally on earth; as a result, it is hygroscopic and rapidly collects water vapour from the air. Because it is an oxidant with strong dehydrating qualities, concentrated sulphuric acid is corrosive to other materials, including rocks and metals. 

Sulphuric Acid in Use

Sulphuric acid is adopted in fertilisers, pigments, dyes, medicines, explosives, detergents, and inorganic salts and acids in different concentrations and petroleum refining and metallurgical operations. Sulphuric acid is used as the electrolyte in lead-acid storage batteries, one of its most well-known uses.

A significant amount of heat is created when sulphuric acid is added to water; hence, water should not be added to the acid in the reverse procedure since the heat released may cause the solution to boil. Hot acid droplets will be sprayed in the process, posing a hazard. When sulphuric acid comes into contact with bodily tissue, it can cause severe acidic chemical burns, dehydration, and secondary thermal burns. Dilute sulphuric acid is far less dangerous since it lacks the oxidative and dehydrating effects, yet, it should be carefully handled because of its acidity.

Dilute Sulphuric Acid Formula

Sulphuric acid in concentrated form is exceedingly corrosive and dangerous. As a result, water is added to it to dilute the concentration. This is referred to as dilute sulphuric acid. The formula for dilute sulphuric acid is similar to that for concentrated acid. The only difference is the concentration. This potent chemical reacts violently with water, generating a lot of heat. As a result, H2SO4 should never be mixed with water. Instead, gently pour in the acid while continually swirling.

Sulphuric Acid Production

The extraction process consists of three steps:

• Burning sulphur or sulphide ores in the air to create SO2.
• Converting SO2 to SO3 by reacting with oxygen in the presence of a catalyst (V2O5).
• Absorbing SO3 in H2SO4 to produce Oleum (H2S2O7).

The SO2 produced is cleaned of dust and impurities such as arsenic compounds. A critical step in creating H2SO4 is the catalytic oxidation of SO2 with O2 to form SO3 in the presence of V2O5 (catalyst).

2SO2(g) + O2(g) → 2SO3(g)

The forward process is exothermic, reversible, and causes a volume reduction. As a result, low temperatures and high pressure are optimal for increasing production. The temperature, however, should not be too low; otherwise, the reaction will take too long to complete.

SO3 +H2SO4 → H2S2O7 (Oleum)

The plant operates at a pressure of 2 bar and a temperature of 720 K. When SO3 gas from the catalytic converter is absorbed in concentrated H2SO4, Oleum is generated. Diluting Oleum with water yields the desired concentration of H2SO4.

Sulphuric Acid Structure

The molecular structure consists of one atom of sulphur, four oxygen atoms, and two hydrogen atoms. H2SO4 is the chemical formula for sulphuric acid. Two hydrogen atoms are firmly bonded to two oxygen atoms in sulphuric acid, resulting in two -OH groups. The molecule is covalent and has a tetrahedral structure.

Properties of Sulphuric Acid

• Pure sulphuric acid has a specific gravity of 1.84 at 288 K and is colourless, thick, and greasy.
• It is soluble in water at all concentrations.
• It results in a continually boiling mixture. The mixture contains 97.3 per cent acid and has a boiling point of 611 Kelvin. As a result, boiling cannot concentrate aqueous sulphuric acid any further than 97.3 per cent.
• It emits massive odours when exposed to moist air.
• When it comes into contact with the skin, it causes severe burns.

Sulphuric Acid Uses

One of the most significant industrial chemicals is sulphuric acid. Every year, more of it is produced than any other man-made chemical. It has a wide range of applications and is used to create practically all manufactured items.

• Sulphuric acid is primarily used in manufacturing fertilisers such as superphosphate of lime and ammonium sulphate.
• It is frequently used in producing chemicals, such as hydrochloric acid and nitric acid, dyes and pigments, explosives, and pharmaceuticals.
• It is used in the petroleum refining process to remove contaminants from gasoline and other refinery products.
• Sulphuric acid is used in metal processing, such as cleaning iron and steel before plating with tin or zinc.
• Sulphuric acid is used in the production of rayon. It is the electrolyte of the lead-acid storage battery, which is extensively used in automobiles.

Conclusion

Sulphuric acid (H2SO4), commonly known as oil of vitriol or hydrogen sulphate, is thick, colourless, oily, and corrosive. It is the most economically significant of all chemicals. Sulphuric acid is produced industrially by the interaction of water with sulphur trioxide, produced through the chemical combination of sulphur dioxide and oxygen via the contact or chamber process. It has a tetrahedral structure with covalent bonds. The acid finds several uses in industrial manufacturing and disinfection processes.