Chlorine is a chemical element with the symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine is a yellow-green gas at room temperature. It is an extremely reactive element and a strong oxidising agent: among the elements, it has the highest electron affinity and the third-highest electronegativity on the revised Pauling scale, behind only oxygen and fluorine. On several scales other than the revised Pauling scale, nitrogen's electronegativity is also listed as greater than chlorine's, such as on the Allen, Allred-Rochow, Martynov-Batsanov, Mulliken-Jaffe, Nagle, and Noorizadeh-Shakerzadeh electronegativity scales.
Nitrogen is the chemical element with the symbol N and atomic number 7. It was first discovered and isolated by Scottish physician Daniel Rutherford in 1772. Although Carl Wilhelm Scheele and Henry Cavendish had independently done so at about the same time, Rutherford is generally accorded the credit because his work was published first. The name nitrogène was suggested by French chemist Jean-Antoine-Claude Chaptal in 1790 when it was found that nitrogen was present in nitric acid and nitrates. Antoine Lavoisier suggested instead the name azote, from the Ancient Greek: ἀζωτικός "no life", as it is an asphyxiant gas; this name is used in several languages, including French, Italian, Russian, Romanian, Portuguese and Turkish, and appears in the English names of some nitrogen compounds such as hydrazine, azides and azo compounds.
Sodium hypochlorite is a chemical compound with the formula NaOCl or NaClO, comprising a sodium cation and a hypochlorite anion. It may also be viewed as the sodium salt of hypochlorous acid. The anhydrous compound is unstable and may decompose explosively. It can be crystallized as a pentahydrate NaOCl·5H
2O, a pale greenish-yellow solid which is not explosive and is stable if kept refrigerated.
Dinitrogen pentoxide is the chemical compound with the formula N2O5, also known as nitrogen pentoxide or nitric anhydride. It is one of the binary nitrogen oxides, a family of compounds that only contain nitrogen and oxygen. It exists as colourless crystals that melt at 41 °C. Its boiling point is 47 °C, and sublimes slightly above room temperature, yielding a colorless gas.
In chemistry, hypochlorite is an anion with the chemical formula ClO−. It combines with a number of cations to form hypochlorite salts. Common examples include sodium hypochlorite and calcium hypochlorite. The Cl-O distance in ClO− is 210 pm.
Nitrogen trichloride, also known as trichloramine, is the chemical compound with the formula NCl3. This yellow, oily, pungent-smelling and explosive liquid is most commonly encountered as a byproduct of chemical reactions between ammonia-derivatives and chlorine (for example, in swimming pools). Alongside monochloramine and dichloramine, trichloramine is responsible for the distinctive 'chlorine smell' associated with swimming pools, where the compound is readily formed as a product from hypochlorous acid reacting with ammonia and other nitrogenous substances in the water, such as urea from urine.
Chlorine trifluoride is an interhalogen compound with the formula ClF3. This colorless, poisonous, corrosive, and extremely reactive gas condenses to a pale-greenish yellow liquid, the form in which it is most often sold (pressurized at room temperature). The compound is primarily of interest as a component in rocket fuels, in plasmaless cleaning and etching operations in the semiconductor industry, in nuclear reactor fuel processing, and other industrial operations.
In chemistry, the valence or valency of an element is the measure of its combining capacity with other atoms when it forms chemical compounds or molecules.
Cyanuric acid or 1,3,5-triazine-2,4,6-triol is a chemical compound with the formula (CNOH)3. Like many industrially useful chemicals, this triazine has many synonyms. This white, odorless solid finds use as a precursor or a component of bleaches, disinfectants, and herbicides. In 1997, worldwide production was 160 million kilograms.
Nitrogen mustards are cytotoxic organic compounds with the chloroethylamine (Cl(CH2)2NR2) functional group. Although originally produced as chemical warfare agents, they were the first chemotherapeutic agents for treatment of cancer. Nitrogen mustards are nonspecific DNA alkylating agents.
Monochloramine, often called simply chloramine, is the chemical compound with the formula NH2Cl. Together with dichloramine (NHCl2) and nitrogen trichloride (NCl3), it is one of the three chloramines of ammonia. It is a colorless liquid at its melting point of −66 °C (−87 °F), but it is usually handled as a dilute aqueous solution, in which form it is sometimes used as a disinfectant. Chloramine is too unstable to have its boiling point measured.
Nitroxyl or azanone is the chemical compound HNO. It is well known in the gas phase. Nitroxyl can be formed as a short-lived intermediate in the solution phase. The conjugate base, NO−, nitroxide anion, is the reduced form of nitric oxide (NO) and is isoelectronic with dioxygen. The bond dissociation energy of H−NO is 49.5 kcal/mol (207 kJ/mol), which is unusually weak for a bond to the hydrogen atom.
Trichloroisocyanuric acid is an organic compound with the formula (C3Cl3N3O3). It is used as an industrial disinfectant, bleaching agent and a reagent in organic synthesis. This white crystalline powder, which has a strong "chlorine odour," is sometimes sold in tablet or granule form for domestic and industrial use. Salts of trichloroisocyanuric acid are known as trichloroisocyanurates.
Chloramines refer to derivatives of ammonia and organic amines wherein one or more N-H bonds have been replaced by N-Cl bonds. Two classes of compounds are considered: inorganic chloramines and organic chloramines.
Tetranitromethane or TNM is an organic oxidizer with chemical formula C(NO2)4. Its chemical structure consists of four nitro groups attached to one carbon atom. In 1857 it was first synthesised by the reaction of sodium cyanoacetamide with nitric acid.
Chloramine-T is the organic compound with the formula CH3C6H4SO2NClNa. Both the anhydrous salt and its trihydrate are known. Both are white powders. Chloramine-T is used as a reagent in organic synthesis.
Halazone is a chemical compound whose formula can be written as either C
7H
5Cl
2NO
4S or (HOOC)(C
6H
4)(SO
2)(NCl
2). It has been widely used to disinfect drinking water.
An azinamine is a theoretical chemical compound in which azide functional groups (–N3) are attached to nitrogen. The simple ones based on ammonia are unknown, but would be H2N–N3, HN(N3)2 and N(N3)3. The last would be a high-energy allotrope of nitrogen (N10).
Chlorine-releasing compounds, also known as chlorine base compounds, is jargon to describe certain chlorine-containing substances that are used as disinfectants and bleaches. They include the following chemicals: sodium hypochlorite, chloramine, halazone, and sodium dichloroisocyanurate. They are widely used to disinfect water and medical equipment, and surface areas as well as bleaching materials such as cloth. The presence of organic matter can make them less effective as disinfectants. They come as a liquid solution, or as a powder that is mixed with water before use.
1,2-Dichloro-1,1,2-trifluoroethane is a volatile liquid chlorofluoroalkane composed of carbon, hydrogen, chlorine and fluorine, and with structural formula CClF2CHClF. It is also known as a refrigerant with the designation R-123a.
