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Uses of Sulfuric Acid

Batul Nafisa Baxamusa Oct 8, 2018
Uses of sulfuric acid in industry and homes are plenty, making it one of the most-used chemicals. The following write-up will answer your questions about the applications of this chemical.
Sulfuric acid, chemically written as H2SO4, is a viscous and oily liquid chemical. There are many uses of this compound, as it is one of the least expensive acids in the world.
In the US, this acid is listed among the most essential or precursor chemicals by the Chemical Diversion and Trafficking Act. Thus, its sale, transfer, export, and import in US has to be regulated and monitored under the Drug Enforcement Administration.

Sulfuric Acid Facts

It is a strong mineral acid that is soluble in water. Its pure and concentrated variety does not occur naturally due to its affinity to water. It is also a part of acid rain, which is formed due to atmospheric oxidation of sulfur dioxide in presence of water.
H2SO4 is a diprotic acid, which means that it can donate 2 protons to a base. It can get ionized in water in two steps:
  1. H2SO4 + H2O (I) ↔ HSO4- (aq) + H3O+ (aq)
  2. HSO4- (aq) + H2O (I) ↔ SO4-2 (aq) + H3O+ (aq)
It can completely dissociate in water, as Ka approaches infinity, and hence, it is classified as a strong acid. It also can take part in redox reactions. It is a good drying agent that can chemically remove water molecules from a number of substances.
For example, C11H22O11 (sucrose molecule) can be completely dehydrated by removal of the eleven molecules of water by this acid. The end product is a black mass of carbon. If one accidentally spills H2SO4 on the skin, it begins to burn through the skin surface, and might even penetrate beneath it, if the chemical is in a concentrated form.
In 1800s, a German chemist called Baron Justus von Liebig discovered that sulfuric acid could be added to soil to increase the availability of phosphorous to the plants. When one cuts onions, it releases propanethiol S-oxide gas, which reaches our eyes.
Here, it reacts with water in the eyes to produce H2SO4. This is a caustic acid that causes the burning sensation in our eyes, which makes them blink and produce tears. Thus, the body's natural way to flush out the irritant acid is in the form of these tears.

What is Sulfuric Acid Used For?

  • In the manufacturing of fertilizers like ammonium sulfate and super phosphate of lime.
  • In the manufacturing of hydrochloric acid, nitric acid, phosphoric acid, ether, plastics, metal sulfates.
  • In the manufacturing of cellophane, dyes, drugs, perfumes, disinfectants, and glue.
  • In the manufacturing of hydrogen by the sulfur-iodine cycle, which is a series of thermo-chemical reactions.
  • In the manufacturing of explosives, nitroglycerin acid, and tri-nitro-toluene (TNT).
  • In the manufacturing of trisodium phosphate, which is a detergent.
  • In potato farming, where it is sprayed on the potato fields before harvesting, to make the stems die out quickly.
  • Removing impurities during the refining process of petroleum.
  • As an electrolyte in lead-acid batteries.
  • In the iron and steel-making industry, for removing oxides from steel rolls before electroplating or galvanizing.
  • In the manufacturing of pigments, such as paints and printing ink.
  • In the chemical industry as a catalyst for important chemical reactions.
  • As an active constituent of household drain cleaners.
  • As a dehydrating agent in its concentrated form, where it absorbs moisture from substances that are in contact with it.
  • In the manufacturing of rayon.
  • In the manufacturing of aluminum sulfate, which is used in the paper industry.
  • In the manufacturing of chemotherapy drugs, which are used to damage the DNA of cancer cells.
  • As a key ingredient in the topical ointment called Debacterol, which is used to treat canker sores and other skin infections.