Austria

Hydrochloric Acid

Hydrochloric Acid, an aqueous solution of hydrogen chloride, is created through the dissolution of hydrogen chloride gas into water. This solution is transparent and possesses a unique, sharp odor. It falls into the category of strong acids and serves as a constituent of the stomach acid present in the digestive systems of nearly all animal species, including humans. Hydrochloric acid holds significance as a vital reagent in laboratories and plays a crucial role in various industrial applications.

Synonyms
HCI, Hydrogen chloride, Muriatic acid, Chlorhydric Acid
Chemical Formula
HCl
CAS Number
7647-01-0

Characteristics

Forms
Liquid (clear)

Uses and Applications

Key applications

  • Metal working
  • Food and Nutrition
  • Laboratory chemicals
  • Leather processing
  • Water treatment
  • Cleaning products
  • Metal finishing
  • Oil and Gas
  • pH control

Genral information about Hydrochloric acid

Hydrochloric acid is also called hydrogen chloride. It is an aqueous, colorless solution of the gas of the same name hydrogen chloride, which is characterized by a pungent odour. It is a strong, inorganic acid that belongs to the mineral acids. The molecular formula is HCI.
Hydrochloric acid is a component of the gastric juices of vertebrates, including humans. In the gastric acid of humans (at a concentration of 0.1% to 0.5%) and in that of animals, hydrochloric acid serves to kill germs. It also breaks down fats and creates the acidic environment of a healthy stomach in which the digestive enzyme pepsin can work optimally.
The salts of hydrochloric acid are found in large quantities in seawater and as rock salt; hydrochloric acid is also found in nature in volcanic gases and crater lakes. The salts of hydrochloric acid are called chlorides, of which sodium chloride (NaCl, table salt) is the best-known. Hydrochloric acid is an important chemical for industries and laboratories for many purposes.

Properties of hydrochloric acid

Hydrochloric acid is produced in the laboratory from sulfuric acid and sodium chloride (common salt). For industrial purposes, hydrogen chloride is produced from chlorine and hydrogen in a chlorine oxyhydrogen gas explosion.
Hydrochloric acid is excellent for removing rust from steel because metal oxides react with hydrochloric acid to form chlorides and water. It dissolves most metals, including precious metals. If hydrochloric acid is mixed with nitric acid, the so-called "aqua regia" is obtained, which even dissolves gold.
If the hydrochloric acid contains a lot of hydrogen chloride, an impressive optical effect occurs: the hydrochloric acid "smokes" - that is, it forms white mist as the hydrogen chloride gas escapes and then reacts with the water in the air to form hydrochloric acid again.
When hydrochloric acid is diluted, it conducts electricity.
iron cast butterfly bodies before the eopxy protection layer coating

Hydrochloric acid in the chemical industry

As an inorganic acid, hydrochloric acid plays an important role in the chemical industry. It is a very useful reagent in chemical analysis because it separates metals from each other. It is also used in alkalimetry.
Hydrochloric acid is also used in the extraction of crude oil and natural gas, as well as in metal processing - in pickling, etching and soldering. It is also used in the processing of ores and rock phosphate.
As a synthesis material, hydrochloric acid is used to obtain other chemical substances such as chlorides or polyvinyl chloride (PVC).
Construction site crane at blue sky clouds background, through glass

Hydrochloric acid in the construction industry

In the construction industry, hydrochloric acid in diluted form helps, for example, to remove mortar residues from masonry. This process is known as "acidizing." Tile layers also use diluted hydrochloric acid to remove the lime film on tiles after grouting.
Hand of man wearing orange rubber gloves is use a hose to clean the tile floor.

Hydrochloric acid in the household

The most widespread use of hydrochloric acid in the household is as a cleaning agent to remove limestone.

Hydrochloric acid in the food industry

As an additive in the food and nutrition industry, hydrochloric acid is labeled E 507.
Variety of pills and capsules

Hydrochloric acid in the pharmaceutical industry

The pharmaceutical industry uses hydrochloric acid in medicines mainly to improve water solubility.

Other uses of hydrochloric acid

Hydrochloric acid is used to produce chemicals for water treatment such as iron(III) chloride and polyaluminium chloride. These substances are used for the extraction of drinking water, wastewater treatment and also for paper production.
Hydrochloric acid is also used to produce calcium chloride, used as road salt during icy weather.
Nickel(II) chloride obtained from hydrochloric acid is used in electroplating and in zinc chloride for electroplating and battery production.
Other applications of hydrochloric acid include personal care and cosmetics, leather manufacturing, pet food, agriculture, lubricant manufacturing and rubber.