Sulfuric acid
[CAS# 7664-93-9]

Identification

• Classification: Inorganic chemical industry >> Inorganic acid
• Name: Sulfuric acid
• Molecular Formula: H₂SO₄
• Molecular Weight: 98.07
• CAS Registry Number: 7664-93-9
• EC Number: 231-639-5
• SMILES: OS(=O)(=O)O

Properties

• Density: 1.841 g/mL (20 ºC) (Expl.)
• Melting point: 10.3 ºC (Expl.)
• Boiling point: 290 ºC (Expl.)
• Flash point: 10 ºC (Expl.)
• Water solubility: miscible (Expl.)

Safety Data

• Hazard Symbols: GHS05 Danger
• Hazard Statements: H314
• Precautionary Statements: P260-P264-P280-P301+P330+P331-P302+P361+P354-P304+P340-P305+P354+P338-P316-P321-P363-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin corrosion	Skin Corr.	1A	H314
Serious eye damage	Eye Dam.	1	H318
Substances or mixtures corrosive to metals	Met. Corr.	1	H290
Specific target organ toxicity - single exposure	STOT SE	3	H335
Skin corrosion	Skin Corr.	1B	H314
Carcinogenicity	Carc.	1A	H350
Carcinogenicity	Carc.	2	H351
Carcinogenicity	Carc.	1A	H350i
Eye irritation	Eye Irrit.	2	H319
Acute toxicity	Acute Tox.	2	H330
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Specific target organ toxicity - repeated exposure	STOT RE	1	H372
Acute toxicity	Acute Tox.	4	H312
Specific target organ toxicity - single exposure	STOT SE	1	H370
Skin corrosion	Skin Corr.	1	H314
Skin corrosion	Skin Corr.	1C	H314
Acute toxicity	Acute Tox.	3	H331
Acute toxicity	Acute Tox.	3	H301

• Transport Information: UN 1786;UN 1830;UN 1832

Discovory and Applicatios

Sulfuric acid, a highly corrosive and potent mineral acid with the formula H₂SO₄, is one of the most widely produced and utilized chemicals in the world. Often referred to as the “king of chemicals,” sulfuric acid has played a crucial role in industry and scientific development since its discovery. Although records of its early use date back to medieval alchemists, it was not until the 18th century that John Roebuck and later, in the 19th century, chemist Joseph-Louis Gay-Lussac, contributed to its industrial production. Today, sulfuric acid is a cornerstone of numerous industries and an essential component in various chemical processes.

Sulfuric acid is primarily known for its applications in the manufacture of fertilizers, particularly phosphates and ammonium sulfate. The production of fertilizers accounts for over 50% of global sulfuric acid consumption. Phosphoric acid, a key ingredient in phosphate fertilizers, is synthesized through the reaction of sulfuric acid with phosphate rock, illustrating sulfuric acid's importance in agriculture and food production. Additionally, ammonium sulfate, another nitrogen-rich fertilizer, relies on sulfuric acid during its synthesis, underscoring the acid’s critical role in increasing global food production.

Beyond agriculture, sulfuric acid is widely used in the chemical industry as a reagent for producing a variety of compounds. It is employed in the manufacture of hydrochloric acid, nitric acid, synthetic detergents, dyes, explosives, and medicines. As a dehydrating agent, sulfuric acid is instrumental in many organic reactions, including the production of esters. Its ability to remove water from substances makes it invaluable in petroleum refining, where it is used to treat impurities and improve fuel quality. Furthermore, sulfuric acid plays an essential role in metal processing and purification, particularly in producing high-quality steel and other metals through processes like pickling, where it removes oxidation from metals.

The electrochemical industry also relies heavily on sulfuric acid. In lead-acid batteries, sulfuric acid acts as the electrolyte that facilitates electron flow between the battery’s electrodes. These batteries, commonly used in automotive and backup power applications, demonstrate sulfuric acid’s role in energy storage and sustainability. The recycling and refining of metals such as copper and zinc similarly utilize sulfuric acid in processes that ensure material recovery and environmental responsibility.

In wastewater treatment, sulfuric acid is used to control pH levels and eliminate contaminants, ensuring that water released back into the environment is safe and suitable for ecosystems. This acid-based treatment is often combined with other chemical processes to address industrial pollutants and hazardous materials, making sulfuric acid essential in environmental protection efforts. Its ability to neutralize alkalinity in water also contributes to its utility in this field.

Historically, sulfuric acid production was associated with environmental challenges due to its emissions. However, modern production methods, such as the contact process, have significantly reduced the environmental impact of sulfuric acid production by improving efficiency and minimizing waste. The contact process involves the catalytic oxidation of sulfur dioxide to sulfur trioxide, which is then absorbed into water to form sulfuric acid. This efficient and scalable process allows for the production of sulfuric acid at a high purity, meeting industrial demand while addressing safety and environmental standards.

In summary, sulfuric acid is an indispensable substance in modern industry with a broad range of applications from agriculture to manufacturing and environmental management. Its continued demand underscores its importance in global industrialization, as well as its potential for future developments in technology, energy, and sustainable practices.

References

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1986. A simple and rapid chemical method for the determination of cephalosporins. Applied Biochemistry and Biotechnology, 12(1).
DOI: 10.1007/bf02798577