"produce tetrachloroaurate. Its acid, chloroauric acid, is then heated to eliminate hydrogen chloride gas. Reaction with aqua regia produces gold(III) chloride: On contact with water, forms acidic hydrates and the conjugate base . It may be reduced by causing elemental gold to be precipitated from solution. Anhydrous AuCl begins to decompose to AuCl at around 160 °C; however, this in turn undergoes disproportionation at higher temperatures to give gold metal and AuCl. AuCl is Lewis acidic and readily forms complexes. For example, it reacts with hydrochloric acid to form chloroauric acid (): Other chloride sources, such as KCl, also convert"
"intermolecular van der Waals forces, which correlates with numbers of electrons in the molecules. Concentrated hydrohalic acid solutions produce visible white fumes. This mist arises from the formation of tiny droplets of their concentrated aqueous solutions of the hydrohalic acid. Upon dissolution in water, which is highly exothermic, the hydrogen halides give the corresponding acids. These acids are very strong, reflecting their tendency to ionize in aqueous solution yielding hydronium ions (HO). With the exception of hydrofluoric acid, the hydrogen halides are strong acids, with acid strength increasing down the group. Hydrofluoric acid is complicated because its strength depends on"
"and cold, away from any organic material and metals. The hydrated form is safer to handle. Calcium hypochlorite Calcium hypochlorite is an inorganic compound with formula (). It is the main active ingredient of commercial products called bleaching powder, chlorine powder, or chlorinated lime, used for water treatment and as a bleaching agents. This compound is relatively stable and has greater available chlorine than sodium hypochlorite (""liquid bleach""). It is a white solid, although commercial samples appear yellow. It strongly smells of chlorine, owing to its slow decomposition in moist air. It is not highly soluble in hard water, and"
"has received numerous reports of nausea, diarrhea, severe vomiting, and life-threatening low blood pressure caused by dehydration. Chlorine dioxide Chlorine dioxide is a chemical compound with the formula ClO. This yellowish-green gas crystallizes as bright orange crystals at −59 °C. As one of several oxides of chlorine, it is a potent and useful oxidizing agent used in water treatment and in bleaching. Chlorine dioxide is a neutral chlorine compound. It is very different from elemental chlorine, both in its chemical structure and in its behavior. One of the most important qualities of chlorine dioxide is its high water solubility, especially"
"hydrolyzes readily, resulting in a dense white smoke consisting of droplets of hydrochloric acid and particles of titanium oxychloride. The titanium tetrachloride smoke is irritant and unpleasant to breathe. It is dispensed from aircraft to create vertical smoke curtains, and during World War II it was a favorite smoke generation agent on warships. Goggles or a respirator should be worn when in contact with the smoke, full protective clothing should be worn when handling liquid FM. In direct contact with skin or eyes, liquid FM causes acid burns. Red phosphorus and white phosphorus (WP) are red or waxy yellow or"
"Calcium hypochlorite Calcium hypochlorite is an inorganic compound with formula (). It is the main active ingredient of commercial products called bleaching powder, chlorine powder, or chlorinated lime, used for water treatment and as a bleaching agents. This compound is relatively stable and has greater available chlorine than sodium hypochlorite (""liquid bleach""). It is a white solid, although commercial samples appear yellow. It strongly smells of chlorine, owing to its slow decomposition in moist air. It is not highly soluble in hard water, and is more preferably used in soft to medium-hard water. It has two forms: ""dry"" (anhydrous); and"
"tetrachloroaluminate AlCl in the presence of chloride ions. Aluminium chloride reacts with calcium and magnesium hydrides in tetrahydrofuran forming tetrahydroaluminates. Aluminium chloride is hygroscopic, having a very pronounced affinity for water. It fumes in moist air and hisses when mixed with liquid water as the Cl ions are displaced with HO molecules in the lattice to form the hexahydrate [Al(HO)]Cl (also white to yellowish in color). The anhydrous phase cannot be regained on heating as HCl is lost leaving aluminium hydroxide or alumina (aluminium oxide): On strong heating (~400 °C), aluminium oxide is formed from the aluminium hydroxide via: Aqueous"
"binary compounds with hydrogen known as the hydrogen halides: hydrogen fluoride (HF), hydrogen chloride (HCl), hydrogen bromide (HBr), hydrogen iodide (HI), and hydrogen astatide (HAt). All of these compounds form acids when mixed with water. Hydrogen fluoride is the only hydrogen halide that forms hydrogen bonds. Hydrochloric acid, hydrobromic acid, hydroiodic acid, and hydroastatic acid are all strong acids, but hydrofluoric acid is a weak acid. All of the hydrogen halides are irritants. Hydrogen fluoride and hydrogen chloride are highly acidic. Hydrogen fluoride is used as an industrial chemical, and is highly toxic, causing pulmonary edema and damaging cells. Hydrogen"
"within 4–6 h and may be delayed up to 8 h. Symptoms include rapid breathing, dyspnea, cough, fever, shivering, sweating, chest and leg pain, myalgias, fatigue, metallic taste, salivation, thirst, and leukocytosis, which can last from 24 to 48 h. In cases of fume inhalation, cortisone preparations should be applied immediately (e.g., by inhalation of Auxiloson) to avoid development of lung edema. Zinc chloride Zinc chloride is the name of chemical compounds with the formula ZnCl and its hydrates. Zinc chlorides, of which nine crystalline forms are known, are colorless or white, and are highly soluble in water. ZnCl itself"
"result in hydroxide and oxide fluorides that have to be reduced with hydrogen fluoride or fluorine gas. It has a monoclinic crystal structure and is isotypic with zirconium tetrafluoride and hafnium tetrafluoride, where the Th ions are coordinated with F ions in somewhat distorted square antiprisms. It is a white, hygroscopic powder: at temperatures above 500 °C, it reacts with atmospheric moisture to produce the oxyfluoride ThOF. Thorium tetrachloride (ThCl, white, m.p. 770 °C) is produced by heating thoria in an organochloride compound such as carbon tetrachloride. The usual method of purification is crystallisation from an aqueous solution and then"
"metal hydroxides are white crystalline solids and dissolve freely in water with evolution of much heat. Alkali hydroxide The alkali hydroxides are a class of chemical compounds which are composed of an alkali metal cation and the hydroxide anion (OH). The alkali hydroxides are: The most common alkali hydroxide is sodium hydroxide, which is readily available in most hardware stores in products such as a drain cleaner. Another common alkali hydroxide is potassium hydroxide. This is available as a solution used for cleaning terraces and other areas made out of wood. All alkali hydroxides are very corrosive, being strongly alkaline."
"Hydrogen fluoride Hydrogen fluoride is a chemical compound with the chemical formula . This colorless gas or liquid is the principal industrial source of fluorine, often as an aqueous solution called hydrofluoric acid. It is an important feedstock in the preparation of many important compounds including pharmaceuticals and polymers (""e.g."" Teflon). HF is widely used in the petrochemical industry as a component of superacids. Hydrogen fluoride boils near room temperature, much higher than other hydrogen halides. Hydrogen fluoride is a highly dangerous gas, forming corrosive and penetrating hydrofluoric acid upon contact with moisture. The gas can also cause blindness by"
"attention upon exposure. Breathing in hydrogen fluoride at high levels or in combination with skin contact can cause death from an irregular heartbeat or from fluid buildup in the lungs. Hydrogen fluoride Hydrogen fluoride is a chemical compound with the chemical formula . This colorless gas or liquid is the principal industrial source of fluorine, often as an aqueous solution called hydrofluoric acid. It is an important feedstock in the preparation of many important compounds including pharmaceuticals and polymers (""e.g."" Teflon). HF is widely used in the petrochemical industry as a component of superacids. Hydrogen fluoride boils near room temperature,"
"Chlorine dioxide Chlorine dioxide is a chemical compound with the formula ClO. This yellowish-green gas crystallizes as bright orange crystals at −59 °C. As one of several oxides of chlorine, it is a potent and useful oxidizing agent used in water treatment and in bleaching. Chlorine dioxide is a neutral chlorine compound. It is very different from elemental chlorine, both in its chemical structure and in its behavior. One of the most important qualities of chlorine dioxide is its high water solubility, especially in cold water. Chlorine dioxide does not hydrolyze when it enters water; it remains a dissolved gas"
"although their toxicity has not been investigated in detail. Dysprosium(III) chloride Dysprosium(III) chloride (DyCl), also known as dysprosium trichloride, is a compound of dysprosium and chlorine. It is a white to yellow solid which rapidly absorbs water on exposure to moist air to form a hexahydrate, DyCl.6HO. Simple rapid heating of the hydrate causes partial hydrolysis to an oxychloride, DyOCl. DyCl is often prepared by the ""ammonium chloride route,"" starting from either DyO or hydrated chloride or oxychloride. or DyCl·6HO. These methods produce (NH)[DyCl]: The pentachloride decomposes thermally according to the following equation: The thermolysis reaction proceeds via the intermediacy"
"the bond dipole moments cancel each other out. Aluminum chloride is a neurotoxin. Anhydrous AlCl reacts vigorously with bases, so suitable precautions are required. It can cause irritation to the eyes, skin, and the respiratory system if inhaled or on contact. Aluminium chloride Aluminium chloride (AlCl) is the main compound of aluminium and chlorine. It is white, but samples are often contaminated with iron(III) chloride, giving it a yellow color. The solid has a low melting and boiling point. It is mainly produced and consumed in the production of aluminium metal, but large amounts are also used in other areas"
"Dysprosium(III) chloride Dysprosium(III) chloride (DyCl), also known as dysprosium trichloride, is a compound of dysprosium and chlorine. It is a white to yellow solid which rapidly absorbs water on exposure to moist air to form a hexahydrate, DyCl.6HO. Simple rapid heating of the hydrate causes partial hydrolysis to an oxychloride, DyOCl. DyCl is often prepared by the ""ammonium chloride route,"" starting from either DyO or hydrated chloride or oxychloride. or DyCl·6HO. These methods produce (NH)[DyCl]: The pentachloride decomposes thermally according to the following equation: The thermolysis reaction proceeds via the intermediacy of (NH)[DyCl]. Treating DyO with aqueous HCl produces hydrated"
"Hydrochloric acid Hydrochloric acid is a colorless inorganic chemical system with the formula . Hydrochloric acid has a distinctive pungent smell. It is mainly produced as a precursor to vinyl chloride for PVC. It is classified as strongly acidic and can attack the skin over a wide composition range, since the hydrogen chloride practically dissociates completely in solution. Hydrochloric acid is the simplest chlorine-based acid system containing water. It is a solution of hydrogen chloride and water, and a variety of other chemical species, including hydronium and chloride ions. It is an important chemical reagent and industrial chemical, used primarily"
"Chloroform Chloroform, or trichloromethane, is an organic compound with formula CHCl. It is a colorless, sweet-smelling, dense liquid that is produced on a large scale as a precursor to PTFE. It is also a precursor to various refrigerants. It is one of the four chloromethanes and a trihalomethane. It is a powerful anesthetic, euphoriant, anxiolytic and sedative when inhaled or ingested. The molecule adopts tetrahedral molecular geometry with C symmetry. The total global flux of chloroform through the environment is approximately tonnes per year, and about 90% of emissions are natural in origin. Many kinds of seaweed produce chloroform, and"
"are unclear, but one unverified hypothesis is the presence of short-lived substances such as dichloromethane in the lower atmosphere. Dichloromethane Methylene dichloride (DCM, or methylene chloride, or dichloromethane) is a geminal organic compound with the formula CHCl. This colorless, volatile liquid with a moderately sweet aroma is widely used as a solvent. Although it is not miscible with water, it is polar, and miscible with many organic solvents. Natural sources of dichloromethane include oceanic sources, macroalgae, wetlands, and volcanoes. However, the majority of dichloromethane in the environment is the result of industrial emissions. DCM is produced by treating either chloromethane"
"contact with hydrogen chloride vapor, a white cloud of ammonium chloride forms, which eventually settles out as a solid in a thin white layer on surfaces. Ammonium cation is found in a variety of salts such as ammonium carbonate, ammonium chloride and ammonium nitrate. Most simple ammonium salts are very soluble in water. An exception is ammonium hexachloroplatinate, the formation of which was once used as a test for ammonium. The ammonium salts of nitrate and especially perchlorate are highly explosive, in these cases ammonium is the reducing agent. In an unusual process, ammonium ions form an amalgam. Such species"
"of data obtained using the Atacama Large Millimeter / submillimeter Array (ALMA), completed in 2017, confirmed substantial amounts of acrylonitrile in Titan's atmosphere. Hydrogen fluoride (HF), like water, is a polar molecule, and due to its polarity it can dissolve many ionic compounds. Its melting point is −84 °C and its boiling point is 19.54 °C (at atmospheric pressure); the difference between the two is a little more than 100 K. HF also makes hydrogen bonds with its neighbor molecules, as do water and ammonia. It has been considered as a possible solvent for life by scientists such as Peter"
"oxidize . The increased levels of hydrogen sulfide could have killed oxygen-generating plants as well as depleted the ozone layer, causing further stress. Small blooms have been detected in modern times in the Dead Sea and in the Atlantic ocean off the coast of Namibia. Hydrogen sulfide Hydrogen sulfide is the chemical compound with the formula . It is a colorless chalcogen hydride gas with the characteristic foul odor of rotten eggs. It is very poisonous, corrosive, and flammable. Hydrogen sulfide is often produced from the microbial breakdown of organic matter in the absence of oxygen gas, such as in"
"halides, such as HCl. Hydrogen bonding amongst HF molecules gives rise to high viscosity in the liquid phase and lower than expected pressure in the gas phase. Hydrogen fluoride does not boil until 20 °C in contrast to the heavier hydrogen halides which boil between −85 °C and −35 °C (−120 °F and –30 °F). HF is fully miscible with water (will dissolve in any proportion), while the other hydrogen halides have large solubility gaps with water. Hydrogen fluoride and water also form several compounds in the solid state, most notably a 1:1 compound that does not melt until −40"
"Hydrogen sulfide Hydrogen sulfide is the chemical compound with the formula . It is a colorless chalcogen hydride gas with the characteristic foul odor of rotten eggs. It is very poisonous, corrosive, and flammable. Hydrogen sulfide is often produced from the microbial breakdown of organic matter in the absence of oxygen gas, such as in swamps and sewers; this process is commonly known as anaerobic digestion which is done by sulfate-reducing microorganisms. also occurs in volcanic gases, natural gas, and in some sources of well water. The human body produces small amounts of and uses it as a signaling molecule."
"Hypochlorous acid Hypochlorous acid (HClO) is a weak acid that forms when chlorine dissolves in water, and itself partially dissociates, forming hypochlorite, ClO. HClO and ClO are oxidizers, and the primary disinfection agents of chlorine solutions. HClO cannot be isolated from these solutions due to rapid equilibration with its precursor. Sodium hypochlorite (NaClO) and calcium hypochlorite (Ca(ClO)), are bleaches, deodorants, and disinfectants. Hypochlorous acid was discovered in 1834 by the French chemist Antoine Jérôme Balard (1802–1876) by adding, to a flask of chlorine gas, a dilute suspension of mercury(II) oxide in water. He also named the acid and its compounds."
"with alcohol in all proportions, is readily soluble in ether and most organic solvents. Coniine dissolves in carbon disulfide, forming a complex thiocarbamate. Coniine solidifies into a soft crystalline mass at −2 °C. It slowly oxidizes in the air. The salts crystallize well and are soluble in water or alcohol. The hydrochloride, B•HCl, crystallizes from water in rhombs, mp. 220 °C, [α] +10.1°; the hydrobromide, in needles, mp. 211 °C, and the -acid tartrate, B•CHO•2 HO, in rhombic crystals, mp. 54 °C. The platinichloride, (B•HCl)•PtCl•HO, separates from concentrated solution as an oil, which solidifies to a mass of orange-yellow crystals,"
"helium condensates (IHCs) (or impurity helium gels) are deposited as a snow like gel in liquid helium when various atoms or molecules are absorbed on the surface of superfluid helium. Atoms can include H, N, Na, Ne, Ar, Kr, Xe, alkalis or alkaline earths. The impurities form nanoparticle clusters coated with localised helium held by van der Waals force. Helium atoms are unable to move towards or away from the impurity, but perhaps can move perpendicularly around the impurity. The snow like solid is structured like an aerogel. When free atoms are included in the condensate a high energy density"
"Sodium chlorate Sodium chlorate is an inorganic compound with the chemical formula NaClO. It is a white crystalline powder that is readily soluble in water. It is hygroscopic. It decomposes above 300 °C to release oxygen and leave sodium chloride. Several hundred million tons are produced annually, mainly for applications in bleaching paper. Industrially, sodium chlorate is produced by the electrolysis of a hot sodium chloride solution: This reaction progresses in heat (at least 70 degrees Celsius), and controlled pH. In lower temperature or with high pH another reaction progresses: 2 NaCl + HO → NaClO + NaCl + H"
"Trihalomethane Trihalomethanes (THMs) are chemical compounds in which three of the four hydrogen atoms of methane (CH) are replaced by halogen atoms. Many trihalomethanes find uses in industry as solvents or refrigerants. THMs are also environmental pollutants, and many are considered carcinogenic. Trihalomethanes with all the same halogen atoms are called haloforms. Several of these are easy to prepare through the haloform reaction. Trihalomethanes were the subject of first drinking water regulations issued after passage of the U.S. Safe Drinking Water Act in 1974. Haloforms Only chloroform has significant applications of the haloforms. In the predominant application, chloroform is required"
"process. Hydroxylammonium chloride reacts with sodium nitrite to give nitrous oxide. If the nitrite is added to the hydroxylamine solution, the only remaining by-product is salt water. If the hydroxylamine solution is added to the nitrite solution (nitrite is in excess), however, then toxic higher oxides of nitrogen also are formed: Treating with and HCl also has been demonstrated: Hyponitrous acid decomposes to NO and water with a half-life of 16 days at 25 °C at pH 1–3. Nitrous oxide is a minor component of Earth's atmosphere, currently with a concentration of about 0.330 ppm. As of 2010, it was"
"sulfate, dissolve in water to give green solutions of the metal aquo complex . The four halides form nickel compounds, which are solids with molecules that feature octahedral Ni centres. Nickel(II) chloride is most common, and its behavior is illustrative of the other halides. Nickel(II) chloride is produced by dissolving nickel or its oxide in hydrochloric acid. It is usually encountered as the green hexahydrate, the formula of which is usually written NiCl•6HO. When dissolved in water, this salt forms the metal aquo complex . Dehydration of NiCl•6HO gives the yellow anhydrous . Some tetracoordinate nickel(II) complexes, e.g. bis(triphenylphosphine)nickel chloride,"
"is an unstable gas with moderate solubility in water. It is usually generated in an aqueous solution and used immediately because it decomposes and is explosive in higher concentrations. It is produced by reacting sodium chlorate with a reducing agent like sulfur dioxide. Chlorine dioxide is sometimes used in combination with chlorine, but it is used alone in ECF (elemental chlorine-free) bleaching sequences. It is used at moderately acidic pH (3.5 to 6). The use of chlorine dioxide minimizes the amount of organochlorine compounds produced. Chlorine dioxide (ECF technology) currently is the most important bleaching method worldwide. About 95% of"