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Inorganic acids, which are also known by the name mineral acids, are acids that are derived from one or more inorganic compounds. When dissolved in water, all inorganic acids though, produce hydrogen ions (H+) and the conjugate base ions. They are corrosive and their solubility is high in water but less soluble or insoluble in organic solvents. Read the complete article to get an insight into the list of important inorganic acids and their properties.
With reference to the characteristics of the number of hydrogen atoms, they are either mono-, di-, or tribasic. The inorganic acids are oxoacids or without oxygen. Some examples of acids with no oxygen are monobasic acids like Hydrochloric acid and Hydrofluoric acid; and bibasic acid, like Hydrogen Sulphide. Acids that contain oxygen include, nitric acid which is monobasic, sulfuric acid which is dibasic and orthophosphoric acid which is tribasic.
The most commonly used acids in science laboratories and the likes are inorganic acids. Some of the important Inorganic acids are given in the next section.
List of Important Inorganic Acids
Inorganic acids are basically, compounds that consist of hydrogen and non-metallic elements or their groups. Let us delve into the following list of important inorganic acids.
- Hydrochloric acid- HCl
- Nitric acid- HNO3
- Phosphoric acid- H3PO4
- Sulphuric acid -H2SO4
- Boric acid- H3BO3
- Hydrofluoric acid- HF
- Hydrobromic acid- HBr
- Perchloric acid- HClO4
- Hydroiodic acid- HI
Inorganic acids can be used for the synthesis of organic and inorganic chemicals based on the chemical compositions and strength of the acid. We have discussed the above list of important inorganic acids in detail. Read on for further enlightenment on the different inorganic acids.
Hydrochloric Acid
Hydrochloric acid is nothing but an aqueous solution of hydrogen chloride. This acid is also known by the name muriatic acid. Classified as a strong acid, Hydrochloric acid is a colourless solution having a distinctively pungent smell. It is also a component of the gastric acid found in the digestive systems of most animal species, including humans. Hydrochloric acid is inevitably an essential laboratory reagent and used as an industrial chemical too.
The chemical formula of Hydrochloric acid is HCl. As it was produced from rock salt, Hydrochloric acid was called spirits of salt or acidum salis (salt acid) by the European alchemists, in the olden times.
Nitric Acid
Nitric acid is a highly corrosive inorganic acid, which is also known as the spirit of nitre and aqua fortis( the Latin word for strong water). Nitrogen in its pure state is colourless, but when left for a longer period of time, it results in a yellow cast due to the process of decomposing into the oxides of nitrogen and water.
Nitric acid that is commercially available the most, has a concentration of 68% in water. When the solution holds more than 86% nitric acid, it is referred to as fuming nitric acid. Depending on the presence of the amount of nitrogen dioxide, fuming nitric acid is further classified as red fuming nitric acid at concentrations above 86%, or white fuming nitric acid with concentrations above 95%.
The chemical formula of Nitric acid is HNO3. The most commonly used strong oxidizing agent is Nitric acid. It is also used with other elements in rocket propellant, as an etchant and cleaning agent as well as in woodworking and metal processing.
Phosphoric Acid
Phosphoric acid is a weak acid that is normally encountered as a syrup that is colourless with an 85% concentration in water. This acid is also known as phosphoric(V) acid and Orthophosphoric acid. Phosphoric acid is a colourless solid in its pure state.
Phosphoric acid is generally encountered as an 85% aqueous solution in laboratories. Moreover, it is an odourless, colourless, and non-volatile syrupy kind of liquid. Although phosphoric acid does meet the strict definition of a weak acid, the 85% solution can still severely damage the eyes and irritate the skin.
The chemical formula of this acid is H3PO4. The most common use of phosphoric acid is in fertilizers, where it is a dormant element. Other than this, it is also used in soaps & detergents, water treatment, toothpaste; and also in the food industry to acidify foods and beverages.
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Sulphuric Acid
Sulphuric acid, the king of acids, is a common mineral acid composed of Sulphur, Oxygen and Hydrogen elements. Another name for sulphuric acid given by the medieval European alchemists is ’ oil of vitriol’ because it was prepared by roasting “green vitriol” in an iron retort.
Sulphuric acid is miscible with water. Moreover, it is a colourless and odourless viscous solution. In its pure form, sulphuric acid is extremely corrosive towards other materials, as it is an oxidant and possesses a strong acidic nature. Additionally, the pure acid is highly dehydrating, meaning it will strip water away from most substances as it comes into contact with them. Its chemical formula is H2SO4.
Further, Sulfuric acid is hygroscopic too, ie it readily absorbs water vapour from the air. On adding sulfuric acid to water, a considerable amount of heat is released. Due to this reason, the reverse process of adding water to concentrated sulfuric acid solutions must not be performed. The heat released may tend to boil the solution, spraying droplets of hot acid in the run. Moreover, when in contact with bodily tissue, pure sulphuric acid, due to dehydration can result in severe chemical burns and even secondary thermal burns; even a tiny amount of the pure acid is dangerous. Diluting solutions of sulfuric acid in water will result in a substantially less hazardous scenario as the oxidative and dehydrating properties are only found in the concentrated acid. However, solutions of the acid in water are anyway strongly acidic, and should therefore still be handled with utmost care.
Sulphuric acid is mostly used in fertilizer manufacture and also in oil refining, chemical synthesis, mineral processing and wastewater processing.
Boric Acid
Boric acid is yet again a weak monobasic acid that is also known as boracic acid, hydrogen borate and orthoboric acid. It is called sassolite when it occurs in its mineral form. It usually exists in the form of colourless crystals or white powder which easily dissolves in water.
H3BO3 is the chemical formula of boric acid. It is mainly used as an antiseptic, insecticide, neuron absorber, flame retardant or even as a precursor to other chemical compounds.
Hydrofluoric Acid
Hydrofluoric acid is nothing but a solution of hydrogen fluoride in water. They are acidic in nature and highly corrosive colourless solution.
The chemical formula is HF. When in contact with human skin, hydrofluoric acids cause deep, painful burns. These acids are commonly used for etching glass and silicon wafers.
Hydrobromic Acid
One of the strongest minerals known on Earth, hydrobromic acid is a strong acid. Its chemical formula is HBr. It is most commonly used for the production of inorganic bromides.
Perchloric Acid
Perchloric acid is a mineral acid that is stronger than sulphuric acid and nitric acid. It is a colourless aqueous solution that is generally safe at room temperature. But when heated it acts as a powerful oxidiser. Perchloric acid is used for preparing perchlorate salts which act as an important component of rocket fuel- ammonium perchlorate.
It readily forms highly explosive mixtures and is a potentially dangerous acid. It has the chemical formula HClO4.
Hydroiodic Acid
Hydroiodic acid is a strong acid that is an aqueous solution of hydrogen iodide. It is a colourless liquid and also known as Hydronium iodide. Its chemical formula is HI.
Properties of Inorganic Acids
Mineral acids or inorganic acids are very much different from their organic counterparts. To know more about organic acids, read the article here. Mineral acids that are most common are sulfuric acid, hydrochloric acid and nitric acid. These inorganic acids are also known as bench acids. Mineral acids range from very strong superacids (perchloric acid) to very weak ones(boric acid). Mineral acids have a tendency to be very soluble in water and insoluble in organic solvents.
Large amounts of these acids – especially sulfuric acid, nitric acid, and hydrochloric acid – are commercially manufactured for use in large plants as feedstocks. Furthermore, for processes like descaling, inorganic acids are also used directly due to their corrosive properties.
We hope this article on the list of important inorganic acids is resourceful and interesting. You can also check out our large collection of GK quizzes and updates on the Entri App. Have a good day mates!
