Hydrochloric acid or muriatic acid is a colorless mineral with the chemical formula HCl.
This compound is in the category of strong acids and can cause severe damage to the skin and the reason is that this substance can be well hydrolyzed in an aqueous solution. This acid is also naturally present in the stomachs of animals and humans and helps digest food.
Different concentrations of this acid are used in industries, the most widely used of which can be considered a 37% solution.
Physical and chemical properties:
Hydrochloric acid is a chemical solution containing hydrogen chloride (HCl). This chemical is transparent, very pungent, colorless, and acidic. As an inorganic acid with a pH between 0 and 2, it has many applications as a strong acid.
When exposed to air, hydrogen chloride produces dense corrosive white vapors.
|Molecular Weight||36.46 g/mol|
|Appearance||Colorless, transparent liquid, fumes in the air if concentrated|
|odor||Pungent, irritating odor|
|Melting point||-114.22 °C (-174°F)|
|Boiling Point||-85.05 °C at 760 mm Hg,|
-121 °F at 760 mm Hg
|Solubility in water||82.3 g/100 g water at 0 °C;|
67.3 g/100 g water at 30 °C;
63.3 g/100 g water at 40 °C;
59.6 g/100 g water at 50 °C;
56.1 g/100 g water at 60 °C
|Solubility||Soluble in ethanol, methanol|
|form||Liquid, Gas Vapor|
|Vapor Pressure||413.6 mm Hg|
|Chemical Structure Depiction|
Purity of HCl:
Hydrochloric acid with a purity of 37 is the most used. However, the highest percentage of purity of this material that can be produced is about 40%. This is due to its high evaporation rate, which has made it difficult to maintain this material.
Laboratory hydrochloric acid 37% is made from concentrated HCl. This substance is generally in the category of chemical grades in ACS grade and reagents. This material is also available in two grades of purified materials: Extra Pure and USP.
Hydrochloric acid is prepared by dissolving hydrogen chloride in water. This acid can be produced in a variety of ways, which means that there are many ways to make hydrochloric acid.
Industrial methods of production of this material:
This substance can be obtained in many concentrations, but concentrations above 50%, need special conditions to be stable because, in this purity, the amount of evaporation of this acid is very high and requires low temperature and high pressure. For this reason, HCl with a purity of more than 50% is stored in special tanks.
Under these conditions, the industrial hydrochloric acid produced is usually between 30 and 35% pure. Of course, lower concentrations are also produced. Concentrations between 20 and 30% are sold under the name of muriatic acid. Concentrations between 10 and 15 percent are also used to clean homes, known as salt ink.
Applications and uses of HCl:
- Production of various chemicals;
- As a chemical reagent in the production of vinyl chloride and plastics PVC, MDI and TDI are used for polyurethane and the synthesis of other organic compounds such as activated carbon, ascorbic acid;
- In the food industry (used as a food additive in the production of gelatin, aspartame, fructose, citric acid, and salt refining);
- Pickling of metals;
- Production of various inorganic compounds;
- Household and industrial cleaners;
- Hydrochloric acid is used to regulate acidity to the purity required by the food, pharmaceutical, and beverage industries.
Pickling of steel:
This material is used to remove iron and steel rust from iron and steel. Acid leaching is used for galvanizing or extrusion before iron and steel enter. A purity of about 20% is usually used for this purpose.
Fe3O4 + Fe + 8 HCl → 4 FeCl2 + 4 H2O
Application of hydrochloric acid in pH control and neutralization:
Hydrochloric acid can be used to regulate the acidity of solutions. In industries where the purity of products is very important (food, pharmaceuticals, drinking water), high-quality hydrochloric acid is used to control the pH of water flows in processes.
Normal quality HCl is sufficient to neutralize effluent flow and control the pH of the swimming pool.
- Vapors and droplets of this substance can cause severe irritation, burns, and blindness.
- It can cause severe skin irritation, redness, blisters and pain, and burns, and skin injuries.
- It can cause corrosive sores in the mouth, throat, esophagus, and abdomen. Symptoms include difficulty swallowing, thirst, vomiting and nausea, diarrhea, severe injuries, coma, and death.
- The vapors of this substance can cause severe irritation of the nose, sore throat, and cough.
- It does not burn and, in contact with metals, produces hydrogen gas, which when mixed with air can cause an explosion.
- Skin Contact: Immediately flush skin with water.
- Inhalation: move the person to the fresh air.
- Eye Contact: Rinse eyes with water for at least 15-20 minutes.
- Ingestion: Do not induce vomiting. Get medical aid immediately. Call a poison control center.
Packing and storage:
Keep the container tightly closed in a cool, dry, ventilated area away from incompatible materials.