There is no word for chlorine, only chlorine.

Chlorine gas, the chemical formula is Cl?. It is yellow-green under normal temperature and pressure. It is a poisonous gas with a strong pungent odor. It is denser than air, soluble in water, easy to compress, and can be liquefied into yellow-green oily liquid chlorine. It is one of the main products of the chlor-alkali industry and can be used Acts as a strong oxidizing agent. There is a danger of explosion when chlorine gas is mixed with hydrogen gas with a volume fraction of more than 5% and exposed to strong light. Chlorine can undergo substitution reactions and addition reactions with organic matter to generate a variety of chlorides. Chlorine was used as a bleaching agent in the paper and textile industries in the early days.

The discovery of chlorine gas should be attributed to the Swedish chemist Scheele. Scheler was a very famous scientist in Europe in the mid-to-late 18th century. He had been an apprentice in a pharmacy since his boyhood. He was obsessed with laboratory work. He did a lot of chemical experiments in a laboratory with simple instruments and equipment. It covers a wide range of topics and has many inventions. With his short but diligent life, he made outstanding contributions to chemistry and won people's respect.

Scheleer discovered chlorine in 1774 when he was studying pyrolusite (manganese dioxide). When he mixed pyrolusite with concentrated hydrochloric acid and heated it, a yellow-green gas was produced. The strong pungent smell of this gas made Scheele feel extremely uncomfortable.

After Scheele prepared chlorine, he dissolved it in water and found that the aqueous solution had a permanent bleaching effect on paper, vegetables and flowers; he also found that chlorine can react with metals or metal oxides A chemical reaction occurs. From Scheler's discovery of chlorine in 1774 to 1810, many scientists successively studied the properties of this gas. During this time, chlorine was treated as a chemical compound. It was not until 1810 that David confirmed that this gas was composed of a chemical element after extensive experimental research. He named this element chlorine. The name comes from Greek and means "green". Early Chinese translations translated it as "green gas", which was later changed to chlorine gas.

Chlorine is a toxic gas that mainly invades the human body through the respiratory tract and dissolves in the water contained in the mucous membrane to generate hypochlorous acid and hydrochloric acid, causing damage to the upper respiratory tract mucosa: hypochlorous acid causes tissue damage Strong oxidation; hydrochloric acid stimulates mucosal inflammation and swelling, causing respiratory mucosa to swell and secrete a large amount of mucus, causing difficulty in breathing. Therefore, the obvious symptom of chlorine poisoning is severe coughing. When symptoms are severe, pulmonary edema may occur, making circulation difficult and leading to death. Chlorine gas entering the body through the esophagus can cause nausea, vomiting, chest pain and diarrhea. The maximum allowed chlorine content in 1L of air is 0.001 mg. Exceeding this amount will cause human poisoning.

1. Reaction of chlorine gas and metal.

Sodium burns violently in chlorine, producing a large amount of white smoke - sodium chloride, which releases heat.

The red-hot copper wire burns violently in the chlorine gas, and the bottle is filled with brown smoke - copper chloride. After adding a small amount of water, the solution turns blue-green (green is more obvious), add enough water Finally, the solution turned completely blue.

The iron wire burned violently in the chlorine gas, and the bottle was filled with brown-red smoke - ferric chloride. After adding a small amount of water, the solution turned yellow.

The magnesium ribbon burns in chlorine gas to form magnesium chloride.

Chlorine gas has strong oxidizing properties and can react with all metals when heated. For example, gold and platinum burn in hot chlorine gas, and react with price-changing metals such as iron and copper to generate high-valent metal chlorides.

2. Reaction of chlorine gas with non-metals.

Pure hydrogen burns quietly in chlorine, emitting a pale flame and white mist appearing at the mouth of the bottle. Put the ignited hydrogen into chlorine. The hydrogen only contacts a small amount of chlorine at the mouth of the tube, generating a small amount of heat. When the mixed gas of hydrogen and chlorine is ignited, a large amount of hydrogen comes into contact with the chlorine and combines rapidly to release a large amount of heat, causing the gas to expand rapidly. And an explosion occurred. The explosion limit of hydrogen in chlorine is 9.8% to 52.8%.

Red phosphorus burns in chlorine gas, emits white smoke and a very light flame, and generates phosphorus trichloride and phosphorus pentachloride.

3. Chlorine gas reacts with compounds.

When chlorine gas meets water, it will produce hypochlorous acid. Hypochlorous acid has a purifying (bleaching) effect and is used for disinfection - the hypochlorous acid generated when dissolved in water has strong oxidizing properties. Chlorine can also react with soluble alkali to form chloride, hypochlorite and water.

Chlorine can also react with salt solution and displace halogen from the salt solution.

Chlorine can also undergo substitution or addition reactions with organic compounds. For example, it can undergo substitution reactions with methane and carbon disulfide, and addition reactions with ethylene.