Hydrochloric Acid (H+ Cl-, H30+ Cl-) also known as muriatic acid or spirits of salt is a strong and colorless acid with a pungent smell which is formed by diatomic molecules ( one atom of hydrogen and one atom of chlorine). These molecules are bonded by a covalent bond.
Hydrochloric Acid which is the aqueous form of hydrogen chloride (HCl) is produced naturally in the stomach as a major constituent of gastric acid which aids the digestion of food.
It is very versatile and can be used for various activities industrially.
It is also very corrosive and harmful and should be handled with care.
Preparation of Hydrochloric Acid
Industrially, Hydrochloric acid is prepared by dissolving hydrogen chloride in water.
However, hydrochloric acid can also be produced in a large scale as a by-product in reactions such as the Chlor-alkali process which involves the electrolyzing of a brine solution to produce chlorine, hydrogen and sodium hydroxide.
The mixture of this chlorine gas in its pure state with hydrogen in the presence of Ultraviolet light produces Hydrogen Chloride, which is then absorbed in deionized water to produce Hydrochloric Acid.
It can also be produced as a by-product in the chlorination process where the hydrogen chloride vapor gotten from this process is absorbed into a weak solution of hydrochloric acid which is then used to produce concentrated hydrochloric acid.
Meanwhile, the chlorination gases without hydrogen chloride gotten from this process are extracted for further processing.
Physical Properties Of Hydrochloric Acid
Hydrochloric Acid is a strong, nonflammable, colorless and transparent acid.
Its boiling point, pH, Melting point, density are dependent on the concentration of Hydrogen chloride in its aqueous solution.
Chemical Properties Of Hydrochloric Acid
Due to the strong nature of Hydrochloric acid, its molecules ionize to form hydrogen ions and chloride ions when dissolved in water.
They are highly corrosive in the presence of copper, aluminium and steel and non-corrosive in the presence of glass.
They are also polar covalent compounds.
Uses Of Hydrochloric Acid
• It is used in industries as a refining agent for metals.
• It is used in titration to determine the number of bases.
• It is used for regulating the acidity of solutions.
• It is used in dissolving metal carbonates, metal oxides and diverse metals.
• It is used as a bleaching agent.
• It is used to galvanise, extrude, roll, pickle and remove rust from iron or steel before cutting or further processing them.
• It is used in regulating the acidity of swimming pools.
• It is used in the production of chemicals like tin, calcium carbonate and phosphoric acid.
• It is also used in the textile, rubber and leather industries.
• In the oil industry, it is used to acidify oil wells.
• It is used in the construction industry for cleaning finished brickwork.
• It is used as a constituent in the production of polyurethane foam.
• It is used to prevent the growth of slime in the paper making industry.
• It is used in the production of vinyl chloride which is used to create PVC Plastic.
• It is used in the production of gelatin products.
• It is used in the production of photo flash bulbs.
• It is used at home to clean bathroom tiles, toilet bowls amongst others.
• It is used in food production and processing.
• It is used in the production of batteries.
• It is used to produce fertilizers.
•It is used as a disinfectant.
Hydrochloric acid has a very irritating smell and is a very harmful substance to living tissues or other materials due to its acidic strength, but that doesn’t apply to rubber. So, you must endeavor to put on protective rubber gloves while handling it or any other harmful solution for the safety of your hands.
Excessive exposure of your eyes to Hydrochloric Acid can lead to severe eye irritation, and permanent loss of sight if not properly attended to.
Exposing it to the skin may lead to severe skin burn and damages. Meanwhile, when you inhale it, it is deposited in your upper respiratory tract, causing pulmonary oedema, severe respiratory irritation, making you cough and choke.
It could also lead to dizziness, low blood pressure, rapid pulse and weakness.
However, if the inhaled hydrochloric acid is concentrated, it can penetrate as deep as the alveoli, further exposing the lungs to intense damage and could cause death.
If ingested, it can cause drooling, vomiting of blood, convulsion, intense chest pain, mouth and throat burn, intense abdominal pain and fever.
It can also lead to the damage of your oesophagus and stomach and even if you survive it, you might be subject to complications like gastric outlet obstruction amongst others.
Despite its vital role in digestion, its excessive secretion in the stomach can cause gastric ulcers while its insufficiency can cause iron-deficiency anaemia.