Hydrogen chloride, with the chemical formula HCl, is a colorless and pungent gas composed of one chlorine atom and one hydrogen atom. Its aqueous solution is called hydrochloric acid, also known as hydrochloric acid. Hydrogen chloride is highly soluble in water, and at 0 ℃, 1 volume of water can dissolve approximately 500 volumes of hydrogen chloride.
Colorless, with a melting point of -114.2 ℃ and a boiling point of -85 ℃. It does not burn in air and is thermally stable. It does not decompose until about 1500 ℃. It has a suffocating odor, strong irritation to the upper respiratory tract, and corrosion to the eyes, skin, and mucous membranes. The density is greater than that of air, and its aqueous solution is hydrochloric acid, while concentrated hydrochloric acid is volatile.
Hydrogen chloride, a corrosive non combustible gas, does not react with water but is easily soluble in water. It often exists in the form of hydrochloric acid acid mist in the air. Easily soluble in ethanol and ether, as well as various other organic compounds; Easily soluble in water, at 25 ℃ and 1 atmospheric pressure, 1 volume of water can dissolve 503 volumes of hydrogen chloride gas. The chemical properties of dry hydrogen chloride are very inactive. Alkali metals and alkaline earth metals can burn in hydrogen chloride, while sodium burns with a bright yellow flame.
The aqueous solution of hydrogen chloride is hydrochloric acid. Industrial hydrochloric acid often appears slightly yellow, mainly due to the presence of ferric chloride. Ammonia is commonly used to test the presence of hydrochloric acid. Ammonia reacts with hydrogen chloride to form white ammonium chloride particles. Hydrogen chloride has a strong dipole that forms hydrogen bonds with other dipoles.
The aqueous solution of hydrogen chloride is hydrochloric acid. Industrial hydrochloric acid often appears slightly yellow, mainly due to the presence of ferric chloride. Ammonia is commonly used to test the presence of hydrochloric acid. Ammonia reacts with hydrogen chloride to form white ammonium chloride particles. Hydrogen chloride has a strong dipole that forms hydrogen bonds with other dipoles.
Electronic grade hydrogen chloride is a high-purity hydrogen chloride gas with a purity of over 99.999%, mainly used in high-tech industries such as semiconductors, electronics, and optoelectronics. This type of gas, due to its high purity and quality, can meet the strict requirements for gas quality in the electronic industry, so its application range is becoming increasingly widespread. It should be noted that electronic grade hydrogen chloride is a liquefied gas with strong corrosiveness and pungent odor, and is toxic upon inhalation. Therefore, special attention should be paid to safety issues during transportation, storage, and use. Electronic grade hydrogen chloride is mainly used in the preparation of monocrystalline silicon, semiconductor, optoelectronics, photovoltaic, flat panel display and other electronic industry fields. In the manufacturing process of monocrystalline silicon, hydrogen chloride is a very important gas, which can make silicon crystal purity up to ppb level. In the semiconductor industry, hydrogen chloride is often used in important processes such as annealing, cleaning, etching and lithography. In the field of optoelectronics, hydrogen chloride can be used to make portable X-ray fluorescence meters, high definition imagers and other devices. In addition, electronic grade hydrogen chloride gas is also used in integrated circuits before epitaxial growth of silicon, passivation, GaAs high temperature etching, gas phase polishing, impurity absorption and cleaning treatment, removal of sodium ions and other aspects.
