What is hydrogen chloride gas?

Hydrogen chloride, chemical formula HCl, is a colorless gas with a strong pungent odor at room temperature and pressure. It consists of a hydrogen atom bonded to a chlorine atom by a covalent bond. Although it is just a simple binary compound, it plays a pivotal role in our life and industrial production.

What are the unique physical properties of hydrogen chloride gas?

Chinese name: 氯化氢

English name: Hydrogen chloride, hydrochloride

Chemical formula: HCl

Molecular weight: 36.461

CAS: 7647-01-0

EINECS: 231-595-7

Density: 1.639 kg/m3 (0 °C, 0.1 MPa)

Melting point: -114.2 °C

Boiling point: -85 °C

The most remarkable physical property of hydrogen chloride gas is that it is highly soluble in water. Under standard conditions, one volume of water dissolves about 500 volumes of hydrogen chloride, a property that makes it a key player in many reactions involving aqueous solutions. In addition, it is denser than air, about 1.26 times denser, which means that if hydrogen chloride gas leaks, it will accumulate lower down. At the same time, its boiling point is low, the boiling point at atmospheric pressure is -85℃, which also determines that it exists in gaseous form at room temperature.

What are the important industrial uses of hydrogen chloride gas?

 "Miracle catalyst" in the field of organic synthesis: hydrogen chloride gas is an indispensable catalyst in many organic synthesis reactions. Take the synthesis of vinyl chloride as an example, it promotes the addition reaction of acetylene and hydrogen chloride to produce vinyl chloride. And vinyl chloride is the production of polyvinyl chloride (PVC) core raw material, PVC is widely used in pipes, plastic doors and Windows, artificial leather and other products manufacturing, from our home plumbing to a variety of plastic products, are inseparable from hydrogen chloride behind the "catalytic contribution".

 The "rust removal guard" of the iron and steel industry: in the process of production and processing of steel, impurities such as rust often form on the surface. That's where hydrogen chloride gas comes in. Put the steel in the acid wash solution containing hydrogen chloride, it can react with rust (the main component is iron oxide), quickly and effectively remove rust, so that the surface of the steel is as clean as new, for the subsequent processing and use to provide a good foundation, to ensure the quality and service life of steel products.

 "Fine processing assistant" in the electronics industry: in the semiconductor chip manufacturing and other electronic industry fields, the purity and surface quality of materials are required to be extremely high. Hydrogen chloride gas is used to etch and clean semiconductor materials such as silicon wafers. It can accurately remove impurities and oxides from the surface of silicon wafers, ensure the accuracy and reliability of chip manufacturing process, and help electronic products continue to develop towards miniaturization and high performance.

What are the preparation methods of hydrogen chloride gas?

1.Laboratory preparation method

Reaction of concentrated sulfuric acid with sodium chloride: this is a more commonly used method in laboratories. The reaction principle is based on the production of low boiling acid (hydrogen chloride) from high boiling acid (concentrated sulfuric acid). Sodium chloride (NaCl) solid was put into a round-bottom flask, and concentrated sulfuric acid (H₂SO₄) was slowly added through a separator funnel. The reaction occurred under heating conditions: The resulting hydrogen chloride gas is dried by concentrated sulfuric acid and then collected by the updrain-air method because it is denser than air. The advantages of this method are that the operation is relatively simple and the raw materials are easy to obtain; The disadvantages are that the reaction requires heat, and the sodium sulfate produced may adhere to the inner wall of the flask, which is not easy to clean.

Concentrated hydrochloric acid drops added to concentrated sulfuric acid: to take advantage of the water absorption and heat-releasing properties of concentrated sulfuric acid when dissolved in water. Place concentrated sulfuric acid in a separator funnel and slowly add concentrated sulfuric acid to a round-bottom flask containing concentrated hydrochloric acid. Concentrated sulfuric acid absorbs water and emits a lot of heat, which makes concentrated hydrochloric acid volatilize to produce hydrogen chloride gas. The method is easy to operate without heating and can produce hydrogen chloride gas quickly. However, due to the volatile nature of concentrated hydrochloric acid, the resulting hydrogen chloride gas may be mixed with a small amount of water vapor and need to be further dried.

Industrial preparation method

Direct synthesis of hydrogen and chlorine: In industry, hydrogen chloride is mainly produced by the reaction of hydrogen gas (H₂) and chlorine gas (Cl₂) under ignition or light conditions. In a special synthesis furnace, pure hydrogen is quietly burned in chlorine gas and reacts:. The generated hydrogen chloride gas can be used for subsequent production after cooling and drying. The advantage of this method is that the raw material is rich, suitable for large-scale production, and can meet the large demand for hydrogen chloride in industry. However, the proportion of hydrogen and chlorine gas needs to be strictly controlled in the reaction process to prevent explosion and other hazards, which has high requirements on equipment and operation.

Organochlorine compounds by-production method: In the production process of some organochlorine compounds, such as the synthesis of chlorobenzene and vinyl chloride, hydrogen chloride gas will be by-produced. Taking chlorobenzene production as an example, benzene (C₆H₆) reacts with chlorine gas under catalyst to produce chlorobenzene (C₆H₅Cl) and hydrogen chloride: By treating and separating the reaction tail gas, high purity hydrogen chloride gas can be recovered. This method not only makes full use of resources, but also reduces the emission of by-products, and has good economic and environmental benefits, but it is subject to the production scale and process of the main product.

Is hydrogen chloride gas harmful to human body?

The harm of hydrogen chloride gas to human body should not be underestimated. When the human body inhale hydrogen chloride gas, it will quickly irritate the respiratory mucosa, causing cough, sore throat, difficulty breathing and other uncomfortable symptoms. If inhaled high concentrations of hydrogen chloride gas, it may even cause pulmonary edema, a serious threat to life safety. Direct skin contact with hydrogen chloride gas or its aqueous solution can cause chemical burns, damage to skin tissue, pain and injury.

Are we exposed to hydrogen chloride gas in our daily life?

In daily life, although we rarely come into direct contact with hydrogen chloride gas, it is not far away from us. For example, hydrogen chloride may be used in the production of some of the food additives we eat, such as citric acid; Some cleaning products, such as toilet cleaners, may also contain hydrogen chloride. However, the amount of hydrogen chloride in these products is strictly controlled and generally does not cause harm to humans as long as they are used correctly.

What if you come into contact with hydrogen chloride gas?

If hydrogen chloride gas is accidentally inhaled, it should be immediately transferred to a place with fresh air and good ventilation to keep the respiratory tract unobstructed. If you have difficulty breathing, give oxygen in time and seek medical attention as soon as possible. If skin comes into contact with hydrogen chloride gas, remove contaminated clothing immediately and rinse the contact area with plenty of running water for at least 15 minutes. Then go to a hospital for professional treatment as soon as possible.

How to buy hydrogen chloride gas?

Hydrogen chloride gas

Purity：
Industrial grade 99.9%
Electronic grade 99.999%

Package
40L,47L,880L

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