Names | |||
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IUPAC name Cadmium dichloride | |||
Other names Cadmium(II) chloride | |||
Identifiers | |||
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3D model (JSmol) |
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3902835 | |||
ChEBI | |||
ChemSpider | |||
ECHA InfoCard | 100.030.256 | ||
EC Number |
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912918 | |||
KEGG | |||
PubChem CID | |||
RTECS number |
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UNII |
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UN number | 2570 | ||
CompTox Dashboard (EPA) |
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Properties | |||
CdCl2 | |||
Molar mass | 183.31 g·mol−1 | ||
Appearance | White solid, hygroscopic | ||
Odor | Odorless | ||
Density | 4.047 g/cm3 (anhydrous) [1] 3.26 g/cm3 (monohydrate) 3.327 g/cm3 (Hemipentahydrate) [2] | ||
Melting point | 568 °C (1,054 °F; 841 K) [2] | ||
Boiling point | 964 °C (1,767 °F; 1,237 K) [2] | ||
Hemipentahydrate: 79.5 g/100 mL (−10 °C) 90 g/100 mL (0 °C) Monohydrate: 119.6 g/100 mL (25 °C) [2] 134.3 g/100 mL (40 °C) 134.2 g/100 mL (60 °C) 147 g/100 mL (100 °C) [3] | |||
Solubility | Soluble in alcohol, selenium(IV) oxychloride, benzonitrile Insoluble in ether, acetone [1] | ||
Solubility in pyridine | 4.6 g/kg (0 °C) 7.9 g/kg (4 °C) 8.1 g/kg (15 °C) 6.7 g/kg (30 °C) 5 g/kg (100 °C) [1] | ||
Solubility in ethanol | 1.3 g/100 g (10 °C) 1.48 g/100 g (20 °C) 1.91 g/100 g (40 °C) 2.53 g/100 g (70 °C) [1] | ||
Solubility in dimethyl sulfoxide | 18 g/100 g (25 °C) [1] | ||
Vapor pressure | 0.01 kPa (471 °C) 0.1 kPa (541 °C) [2] | ||
−6.87·10−5 cm3/mol [2] | |||
Viscosity | 2.31 cP (597 °C) 1.87 cP (687 °C) [1] | ||
Structure | |||
Rhombohedral, hR9 (anhydrous) [4] Monoclinic (hemipentahydrate) [3] | |||
R3m, No. 166 (anhydrous) [4] | |||
3 2/m (anhydrous) [4] | |||
α = 90°, β = 90°, γ = 120° | |||
Thermochemistry | |||
Heat capacity (C) | 74.7 J/mol·K [2] | ||
Std molar entropy (S⦵298) | 115.3 J/mol·K [2] | ||
Std enthalpy of formation (ΔfH⦵298) | −391.5 kJ/mol [2] | ||
Gibbs free energy (ΔfG⦵) | −343.9 kJ/mol [2] | ||
Hazards | |||
GHS labelling: | |||
[5] | |||
Danger | |||
H301, H330, H340, H350, H360, H372, H410 [5] | |||
P210, P260, P273, P284, P301+P310, P310 [5] | |||
NFPA 704 (fire diamond) | |||
Lethal dose or concentration (LD, LC): | |||
LD50 (median dose) | 94 mg/kg (rats, oral) [1] 60 mg/kg (mouse, oral) 88 mg/kg (rat, oral) [6] | ||
NIOSH (US health exposure limits): | |||
PEL (Permissible) | [1910.1027] TWA 0.005 mg/m3 (as Cd) [7] | ||
REL (Recommended) | Ca [7] | ||
IDLH (Immediate danger) | Ca [9 mg/m3 (as Cd)] [7] | ||
Safety data sheet (SDS) | External MSDS | ||
Related compounds | |||
Other anions | Cadmium fluoride Cadmium bromide Cadmium iodide | ||
Other cations | Zinc chloride Mercury(II) chloride Calcium chloride | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Cadmium chloride is a white crystalline compound of cadmium and chloride, with the formula CdCl2. This salt is a hygroscopic solid that is highly soluble in water and slightly soluble in alcohol. The crystal structure of cadmium chloride (described below), is a reference for describing other crystal structures. Also known are CdCl2•H2O and the hemipenahydrate CdCl2•2.5H2O. [2]
Anhydrous cadmium chloride forms a layered structure consisting of octahedral Cd2+ centers linked with chloride ligands. Cadmium iodide, CdI2, has a similar structure, but the iodide ions are arranged in a HCP lattice, whereas in CdCl2 the chloride ions are arranged in a CCP lattice. [8] [9]
The anhydrous form absorbs moisture from the air to form various hydrates. Three of these hydrates have been examined by X-ray crystallography.
Compound | CdCl2·H2O [10] | CdCl2·2.5H2O [11] | CdCl2·4H2O [12] |
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Molar mass (g/mol) | 201.33 | 228.36 | 255.38 |
Crystal Structure | Orthorhombic | Monoclinic | Orthorhombic |
Space Group | Pnma | P21/n | P212121 |
Lattice constant a (Å) | 9.25 | 9.21 | 12.89 |
Lattice constant b (Å) | 3.78 | 11.88 | 7.28 |
Lattice constant c (Å) | 11.89 | 10.08 | 15.01 |
β | 93.5° | ||
Density (g/cm3) | 3.26 | 2.84 | 2.41 |
Comment | Interconnected CdCl3(H2O) octahederons | Distorted trans-[CdCl2(H2O)4] octahedrons |
Cadmium chloride dissolves well in water and other polar solvents. It is a mild Lewis acid. [8]
Solutions of equimolar cadmium chloride and potassium chloride give potassium cadmium trichloride. [13] With large cations, it is possible to isolate the trigonal bipyramidal [CdCl5]3− ion.
Cadmium metal is soluble in molten cadmium chloride, produced by heating cadmium chloride above 568 °C. Upon cooling, the metal precipitates. [14]
Anhydrous cadmium chloride can be prepared by the reaction of hydrochloric acid and cadmium metal or cadmium oxide. [14]
The anhydrous salt can also be prepared from anhydrous cadmium acetate using hydrogen chloride or acetyl chloride. [15]
Industrially, it is produced by the reaction of molten cadmium and chlorine gas at 600 °C. [14]
The monohydrate, hemipentahydrate, and tetrahydrate can be produced by evaporation of the solution of cadmium chloride at 35, 20, and 0 °C respectively. The hemipentahydrate and tetrahydrate release water in air. [10] [11] [12]
Cadmium chloride is used for the preparation of cadmium sulfide, used as "cadmium yellow", a brilliant-yellow stable inorganic pigment. [14]
In the laboratory, anhydrous CdCl2 can be used for the preparation of organocadmium compounds of the type R2Cd, where R is an aryl or a primary alkyl. These were once used in the synthesis of ketones from acyl chlorides: [16]
Such reagents have largely been supplanted by organocopper compounds, which are much less toxic.
Cadmium chloride is also used for photocopying, dyeing and electroplating.
Like all cadmium compounds, CdCl
2 is highly toxic and appropriate safety precautions must be taken when handling it.
Barium chloride is an inorganic compound with the formula BaCl2. It is one of the most common water-soluble salts of barium. Like most other water-soluble barium salts, it is a white powder, highly toxic, and imparts a yellow-green coloration to a flame. It is also hygroscopic, converting to the dihydrate BaCl2·2H2O, which are colourless crystals with a bitter salty taste. It has limited use in the laboratory and industry.
Cadmium sulfate is the name of a series of related inorganic compounds with the formula CdSO4·xH2O. The most common form is the monohydrate CdSO4·H2O, but two other forms are known CdSO4·8⁄3H2O and the anhydrous salt (CdSO4). All salts are colourless and highly soluble in water.
In chemistry, water(s) of crystallization or water(s) of hydration are water molecules that are present inside crystals. Water is often incorporated in the formation of crystals from aqueous solutions. In some contexts, water of crystallization is the total mass of water in a substance at a given temperature and is mostly present in a definite (stoichiometric) ratio. Classically, "water of crystallization" refers to water that is found in the crystalline framework of a metal complex or a salt, which is not directly bonded to the metal cation.
Manganese(II) chloride is the dichloride salt of manganese, MnCl2. This inorganic chemical exists in the anhydrous form, as well as the dihydrate (MnCl2·2H2O) and tetrahydrate (MnCl2·4H2O), with the tetrahydrate being the most common form. Like many Mn(II) species, these salts are pink, with the paleness of the color being characteristic of transition metal complexes with high spin d5 configurations.
Chromium(III) chloride (also called chromic chloride) is an inorganic chemical compound with the chemical formula CrCl3. It forms several hydrates with the formula CrCl3·nH2O, among which are hydrates where n can be 5 (chromium(III) chloride pentahydrate CrCl3·5H2O) or 6 (chromium(III) chloride hexahydrate CrCl3·6H2O). The anhydrous compound with the formula CrCl3 are violet crystals, while the most common form of the chromium(III) chloride are the dark green crystals of hexahydrate, CrCl3·6H2O. Chromium chlorides find use as catalysts and as precursors to dyes for wool.
Nickel(II) chloride (or just nickel chloride) is the chemical compound NiCl2. The anhydrous salt is yellow, but the more familiar hydrate NiCl2·6H2O is green. Nickel(II) chloride, in various forms, is the most important source of nickel for chemical synthesis. The nickel chlorides are deliquescent, absorbing moisture from the air to form a solution. Nickel salts have been shown to be carcinogenic to the lungs and nasal passages in cases of long-term inhalation exposure.
Iron(II) fluoride or ferrous fluoride is an inorganic compound with the molecular formula FeF2. It forms a tetrahydrate FeF2·4H2O that is often referred to by the same names. The anhydrous and hydrated forms are white crystalline solids.
Uranyl chloride refers to inorganic compounds with the formula UO2Cl2(H2O)n where n = 0, 1, or 3. These are yellow-colored salts.
Zinc bromide (ZnBr2) is an inorganic compound with the chemical formula ZnBr2. It is a colourless salt that shares many properties with zinc chloride (ZnCl2), namely a high solubility in water forming acidic solutions, and good solubility in organic solvents. It is hygroscopic and forms a dihydrate ZnBr2·2H2O.
Zinc nitrate is an inorganic chemical compound with the formula Zn(NO3)2. This colorless, crystalline salt is highly deliquescent. It is typically encountered as a hexahydrate Zn(NO3)2·6H2O. It is soluble in both water and alcohol.
Cadmium iodide is the inorganic compound with the formula CdI2. It is a white hygroscopic solid. It also can be obtained as a mono- and tetrahydrate. It has few applications. It is notable for its crystal structure, which is typical for compounds of the form MX2 with strong polarization effects.
Cadmium nitrate describes any of the related members of a family of inorganic compounds with the general formula , the most commonly encountered form being the tetrahydrate. The anhydrous form is volatile, but the others are colourless crystalline solids that are deliquescent, tending to absorb enough moisture from the air to form an aqueous solution. Like other cadmium compounds, cadmium nitrate is known to be carcinogenic.
Iron(III) nitrate, or ferric nitrate, is the name used for a series of inorganic compounds with the formula Fe(NO3)3.(H2O)n. Most common is the nonahydrate Fe(NO3)3.(H2O)9. The hydrates are all pale colored, water-soluble paramagnetic salts.
Cadmium bromide is the inorganic compound with the formula CdBr2. It is a white hygroscopic solid. It also can be obtained as a mono- and tetrahydrate. It has few applications.
Chromium(III) nitrate describes several inorganic compounds consisting of chromium, nitrate and varying amounts of water. Most common is the dark violet hygroscopic solid. An anhydrous green form is also known. Chromium(III) nitrate compounds are of a limited commercial importance, finding some applications in the dyeing industry. It is common in academic laboratories for the synthesis of chromium coordination complexes.
Cadmium acetate is the chemical compound with the formula Cd(O2CCH3)2(H2O)2. The compound is marketed both as the anhydrous form and as a dihydrate, both of which are white or colorless. Only the dihydrate has been verified by X-ray crystallography.
Cadmium hydroxide is an inorganic compound with the formula Cd(OH)2. It is a white crystalline ionic compound that is a key component of nickel–cadmium battery.
Beryllium sulfate normally encountered as the tetrahydrate, [Be(H2O)4]SO4 is a white crystalline solid. It was first isolated in 1815 by Jons Jakob Berzelius. Beryllium sulfate may be prepared by treating an aqueous solution of many beryllium salts with sulfuric acid, followed by evaporation of the solution and crystallization. The hydrated product may be converted to anhydrous salt by heating at 400 °C.
Beryllium nitrate is an inorganic compound with the idealized chemical formula Be(NO3)2. The formula suggests a salt, but, as for many beryllium compounds, the compound is highly covalent. Little of its chemistry is well known. "When added to water, brown fumes are evolved; when hydrolyzed in sodium hydroxide solution, both nitrate and nitrite ions are produced."
Potassium heptafluorotantalate is an inorganic compound with the formula K2[TaF7]. It is the potassium salt of the heptafluorotantalate anion [TaF7]2−. This white, water-soluble solid is an intermediate in the purification of tantalum from its ores and is the precursor to the metal.