Specification parameters

Essential information

Hydrochloric acid is an aqueous solution of hydrogen chloride (HCl), which is a strong inorganic acid with a wide range of industrial applications. Hydrochloric acid is a colorless and transparent liquid with a strong pungent odor and high corrosiveness. Concentrated hydrochloric acid (with a mass fraction of about 37%) has extremely strong volatility, so when the container containing concentrated hydrochloric acid is opened, the hydrogen chloride gas will evaporate and combine with water vapor in the air to produce small droplets of hydrochloric acid, causing acid mist to appear above the bottle mouth. Hydrochloric acid is the main component of stomach acid, which can promote food digestion and resist microbial infections.

Application area 
Biological use
There is a special gland on the stomach wall of humans and other animals that can turn ingested salt into hydrochloric acid. Hydrochloric acid is a component of gastric juice (with a concentration of about 0.5%), which can maintain the most suitable pH value for activating gastric protease in gastric juice. It can also denature proteins in food and make them easier to hydrolyze, as well as kill bacteria that enter the stomach with food. In addition, after entering the small intestine, hydrochloric acid can promote the secretion of pancreatic and intestinal fluids, as well as the secretion and excretion of bile. The acidic environment also facilitates the absorption of iron and calcium in the small intestine.
Daily use
By utilizing the property of hydrochloric acid reacting with insoluble bases, daily necessities such as toilet cleaner and rust remover can be produced.  

 Industrial use
Hydrochloric acid is an inorganic strong acid solution that has a wide range of applications in industrial processing, such as metal refining. Hydrochloric acid often determines the quality of products.
 
Analytical chemistry
In analytical chemistry, when using acid to determine the concentration of alkali, hydrochloric acid is generally used for titration. Titration with a strong acid solution can make the endpoint more pronounced, resulting in more accurate results. At 1 standard atmospheric pressure, 20.2% hydrochloric acid can form an azeotropic solution, which is commonly used as a reference substance for quantitative analysis at a certain pressure. The concentration at constant boiling will change with the change of air pressure.  

Packaging, Storage, Transportation, and Safety

Store in a cool and ventilated warehouse. The storage temperature shall not exceed 30 ℃, and the relative humidity shall not exceed 85%. Keep the container sealed. It should be stored separately from alkalis, amines, alkali metals, and flammable materials, and avoid mixing storage. The storage area should be equipped with emergency response equipment for leaks and suitable containment materials.