Acids are chemical compounds that include hydrogen atoms that can be replaced by metal particles and an acid residue. They can also be defined as substances that can react with a chemical base to form salt and water.
There are two main types of these compounds: strong and weak. They can also be classified as mineral and organic acids depending on their chemical composition. The main difference between the two is that the former are inorganic compounds consisting of various combinations of chemical elements, while the latter are a combination of carbon and hydrogen atoms.
Definition
Mineral acid is a substance synthesized from one or more inorganic compounds. It releases hydrogen ions in solution, from which, in turn, hydrogen can be displaced by the metal to form a salt. Different acids have different formulas. For example, sulfuric acid is H2SO4, and nitric acid is HNO3.
Salts of mineral acids are contained inside living organisms, dissolved in water (in the form of ions) or are in a solid state (for example, calcium and phosphorus salts in the human skeleton and most vertebrates).
One common characteristic of all acids is that they always have at least one hydrogen atom in their molecule. All of them participate in the neutralization reaction, reacting with bases and forming salts and water. Other properties of acids are sour taste and the ability to cause discoloration of some dyes. A typical example of this is the conversion of a tint of litmus paper from blue to red.
Mineral acids are highly soluble in water. They absolutely do not mix with organic solvents. Most of them are very aggressive.
Inorganic Acid List
Minerals include the following substances:
- Hydrochloric acid - HCl.
- Nitric acid - HNO3.
- Phosphoric acid - H3PO4.
- Sulfuric acid - H2SO4.
- Boric acid - H3BO3.
- Hydrofluoric acid - HF.
- Hydrobromic acid - HBr.
- Perchloric acid - HClO4.
- Hydroiodic acid - HI.
The so-called reference acids - hydrochloric, sulfuric and nitric - are the most commonly used. Next, we consider in more detail.
Hydrochloric acid
A concentrated substance is an aqueous solution containing about 38% hydrogen chloride (HCl). It has a pungent odor, causing burns to the respiratory system and eyes. Hydrochloric acid is not classified as an oxidizing agent or reducing agent. However, when mixed, for example, with sodium hypochlorite (bleach) or potassium permanganate, it releases toxic chlorine gas.
Being a non-oxidizing acid, HCl dissolves most base metals, releasing flammable hydrogen gas.
Nitric acid (HNO3)
Nitric acid is supplied as a concentrated solution (68-70%, 16 M) and in anhydrous form (100%). It is a strong oxidizing agent. Properties are preserved even if it is sufficiently diluted and is at room temperature. This substance oxidizes most organic compounds, turning into nitrous oxide. It can form explosive mixtures with almost any organic compound.
Concentrated nitric acid reacts violently with organic material, which leads to gas evolution and potential pressure increase, after which the vessel ruptures if the container is not properly ventilated. Oxidation reactions with some organic solvents can form explosive nitrates.
Nitric acid interacts with most metals, releasing either hydrogen gas or nitrogen oxides, depending on the concentration and type of reagent. It does not dissolve gold and platinum.
Mixing nitric and hydrochloric acid will result in the formation of brown vapors consisting of toxic nitrogen oxides.
The substance causes the appearance of yellow spots on the skin.
Sulfuric acid (H2SO4)
The concentrated substance is often supplied in 98% solution (18 M). It is a strong oxidizing agent, hygroscopic and a powerful dehydrating agent.
The diluted substance reacts with metals like other mineral acids, releasing hydrogen gas. The concentrated compound can also dissolve some noble metals such as copper, silver and mercury, releasing sulfur dioxide (SO2). Lead and tungsten do not react with sulfuric acid.
Due to its strong oxidizing and dehydrating ability, it reacts violently with many organic chemicals, which leads to the release of gas.
Phosphoric Acid (H3PO4)
Pure phosphoric compound is a water-soluble crystalline solid. The acid, most often sold as an 85% aqueous solution, is viscous, non-volatile and odorless. It is less reactive than other mineral acids discussed above.
Dissolving in water, the substance makes the fluid viscous and viscous.
The use of mineral acids
Inorganic acids range from acids with high strength (sulfuric) to very weak (boric). They tend to be soluble in water and not miscible with organic solvents.
Mineral acids are used in many sectors of the chemical industry as raw materials for the synthesis of other chemicals, both organic and inorganic. A large number of them, especially sulfuric, nitrogen and hydrochloric, are produced for commercial use in large factories.
They are also widely used due to their corrosive properties. For example, a dilute hydrochloric acid solution is used to remove deposits inside boilers. This process is known as descaling.
In everyday life, sulfuric acid can be used for car batteries and surface cleaning. Just a few decades ago, people regularly bought bottles of this substance to charge their car batteries.
Nitric acid (HNO 3 ) is used in dry cleaning. Phosphoric acid (H 3 PO 4 ) is used in the manufacture of matches.
Similarity
Between inorganic and organic acids, there are characteristics that combine them into one group. The list of them is as follows:
- Protons (H ions) can be released.
- React with chemical bases.
- They have strong and weak acidity.
- The blue litmus test is stained red.
- The interaction of acids and minerals.
Differences
The following discrepancies are distinguished between inorganic and organic acids:
- Definition Mineral acids are substances derived from inorganic compounds. Organic acids are organic compounds with acidic properties.
- Origin. Most mineral acids are not of biological origin, for example, mineral sources. With organic compounds, the opposite is true.
- Solubility. Most mineral acids dissolve well in water. Organic compounds do not mix well with liquids.
- Acidity. Most mineral acids are strong. Organic are usually weak.
- Chemical composition. Mineral acids may or may not have carbon atoms in their structure. In organic compounds, they are always present.
The article presents data on acids and their properties.