Cadmium chloride

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Cadmium chloride
Ball-and-stick model of cadmium chloride Cadmium-chloride-3D-balls.png
Ball-and-stick model of cadmium chloride
Cadmium chloride in polyhedron shape Cadmium-chloride-3D-polyhedra.png
Cadmium chloride in polyhedron shape
Cadmium chloride hemipentahydrate.jpg
Names
IUPAC name
Cadmium dichloride
Other names
Cadmium(II) chloride
Identifiers
3D model (JSmol)
3902835
ChEBI
ChemSpider
ECHA InfoCard 100.030.256 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 233-296-7
  • (hemipentahydrate):813-696-3
912918
KEGG
PubChem CID
RTECS number
  • EV0175000
UNII
UN number 2570
  • InChI=1S/Cd.2ClH/h;2*1H/q+2;;/p-2 Yes check.svgY
    Key: YKYOUMDCQGMQQO-UHFFFAOYSA-L Yes check.svgY
  • InChI=1/Cd.2ClH/h;2*1H/q+2;;/p-2
    Key: YKYOUMDCQGMQQO-NUQVWONBAG
  • (hemipentahydrate):InChI=1S/2Cd.4ClH.5H2O/h;;4*1H;5*1H2/q2*+2;;;;;;;;;/p-4
    Key: DZVRGWYMCGLNKJ-UHFFFAOYSA-J
  • (monohydrate):InChI=1S/Cd.2ClH.H2O/h;2*1H;1H2/q+2;;;/p-2
    Key: OISMQLUZKQIKII-UHFFFAOYSA-L
  • [Cd+2].[Cl-].[Cl-]
  • (hemipentahydrate):O.O.O.O.O.[Cl-].[Cl-].[Cl-].[Cl-].[Cd+2].[Cd+2]
  • (monohydrate):O.[Cl-].[Cl-].[Cd+2]
Properties
CdCl2
Molar mass 183.31 g·mol−1
AppearanceWhite 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]
a = 3.846 Å, c = 17.479 Å (anhydrous) [4]
α = 90°, β = 90°, γ = 120°
Thermochemistry
74.7 J/mol·K [2]
Std molar
entropy (S⦵298)
115.3 J/mol·K [2]
−391.5 kJ/mol [2]
−343.9 kJ/mol [2]
Hazards
GHS labelling:
GHS-pictogram-skull.svg GHS-pictogram-silhouette.svg GHS-pictogram-pollu.svg [5]
Danger
H301, H330, H340, H350, H360, H372, H410 [5]
P210, P260, P273, P284, P301+P310, P310 [5]
NFPA 704 (fire diamond)
NFPA 704.svgHealth 4: Very short exposure could cause death or major residual injury. E.g. VX gasFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
4
0
0
Lethal dose or concentration (LD, LC):
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).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)

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 hemipentahydrate CdCl2•2.5H2O. [2]

Contents

Structure

Anhydrous

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]

Hydrates

Subunit of CdCl2(H2O)2.5. Color code: red = O (of H2O), blue = Cd, green = Cl. 1843-ICSD.png
Subunit of CdCl2(H2O)2.5. Color code: red = O (of H2O), blue = Cd, green = Cl.

The anhydrous form absorbs moisture from the air to form various hydrates. Three of these hydrates have been examined by X-ray crystallography.

Crystallographic data for the 3 hydrates of cadmium chloride
CompoundCdCl2·H2O [10] CdCl2·2.5H2O [11] CdCl2·4H2O [12]
Molar mass (g/mol)201.33228.36255.38
Crystal Structure Orthorhombic Monoclinic Orthorhombic
Space GroupPnmaP21/nP212121
Lattice constant a (Å)9.259.2112.89
Lattice constant b (Å)3.7811.887.28
Lattice constant c (Å)11.8910.0815.01
β93.5°
Density (g/cm3)3.262.842.41
CommentInterconnected CdCl3(H2O) octahederonsDistorted trans-[CdCl2(H2O)4] octahedrons

Chemical properties

Cadmium chloride dissolves well in water and other polar solvents. It is a mild Lewis acid. [8]

CdCl2 + 2 Cl− → [CdCl4]2−

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]

Preparation

Anhydrous cadmium chloride can be prepared by the reaction of hydrochloric acid and cadmium metal or cadmium oxide. [14]

Cd + 2 HCl → CdCl2 + H2

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]

Uses

Cadmium chloride is used for the preparation of cadmium sulfide, used as "cadmium yellow", a brilliant-yellow stable inorganic pigment. [14]

CdCl
2 + H
2S → CdS + 2 HCl

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]

CdCl
2 + 2 RMgX → R
2Cd + MgCl
2 + MgX
2
R
2Cd + 2R'COCl → 2R'COR + CdCl
2

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.

Related Research Articles

Iron(III) chloride describes the inorganic compounds with the formula FeCl3(H2O)x. Also called ferric chloride, these compounds are some of the most important and commonplace compounds of iron. They are available both in anhydrous and in hydrated forms, which are both hygroscopic. They feature iron in its +3 oxidation state. The anhydrous derivative is a Lewis acid, while all forms are mild oxidizing agents. It is used as a water cleaner and as an etchant for metals.

<span class="mw-page-title-main">Zinc chloride</span> Chemical compound

Zinc chloride is an inorganic chemical compound with the formula ZnCl2·nH2O, with n ranging from 0 to 4.5, forming hydrates. Zinc chloride, anhydrous and its hydrates, are colorless or white crystalline solids, and are highly soluble in water. Five hydrates of zinc chloride are known, as well as four forms of anhydrous zinc chloride.

<span class="mw-page-title-main">Barium chloride</span> Chemical compound

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.

<span class="mw-page-title-main">Cadmium sulfate</span> Chemical compound

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.

<span class="mw-page-title-main">Manganese(II) chloride</span> Chemical compound

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.

<span class="mw-page-title-main">Chromium(III) chloride</span> Chemical compound

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.

<span class="mw-page-title-main">Nickel(II) chloride</span> Chemical compound

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.

<span class="mw-page-title-main">Rhodium(III) chloride</span> Chemical compound

Rhodium(III) chloride refers to inorganic compounds with the formula RhCl3(H2O)n, where n varies from 0 to 3. These are diamagnetic red-brown solids. The soluble trihydrated (n = 3) salt is the usual compound of commerce. It is widely used to prepare compounds used in homogeneous catalysis.

<span class="mw-page-title-main">Chromium(II) chloride</span> Chemical compound

Chromium(II) chloride describes inorganic compounds with the formula CrCl2(H2O)n. The anhydrous solid is white when pure, however commercial samples are often grey or green; it is hygroscopic and readily dissolves in water to give bright blue air-sensitive solutions of the tetrahydrate Cr(H2O)4Cl2. Chromium(II) chloride has no commercial uses but is used on a laboratory-scale for the synthesis of other chromium complexes.

<span class="mw-page-title-main">Zinc bromide</span> Chemical compound

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.

<span class="mw-page-title-main">Zinc nitrate</span> Chemical compound

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.

<span class="mw-page-title-main">Cadmium iodide</span> Chemical compound

Cadmium iodide is an 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.

<span class="mw-page-title-main">Cadmium nitrate</span> Chemical compound

Cadmium nitrate describes any of the related members of a family of inorganic compounds with the general formula Cd(NO3)2·xH2O. 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. According to X-ray crystallography, the tetrahydrate features octahedral Cd2+ centers bound to six oxygen ligands.

<span class="mw-page-title-main">Iron(III) nitrate</span> Chemical compound

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.

<span class="mw-page-title-main">Cadmium bromide</span> Chemical compound

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.

<span class="mw-page-title-main">Cadmium acetate</span> Chemical compound

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.

<span class="mw-page-title-main">Cadmium hydroxide</span> Chemical compound

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.

<span class="mw-page-title-main">Beryllium sulfate</span> Chemical compound

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.

<span class="mw-page-title-main">Manganese(II) iodide</span> Chemical compound

Manganese(II) iodide is the chemical compound composed of manganese and iodide with the formula MnI2(H2O)n. The tetrahydrate is a pink solid while the anhydrous derivative is beige. Both forms feature octahedral Mn centers. Unlike MnCl2(H2O)4 and MnBr2(H2O)4 which are cis, MnI2(H2O)4 is trans.

References

  1. 1 2 3 4 5 6 7 Anatolievich, Kiper Ruslan. "cadmium chloride". chemister.ru. Retrieved 2014-06-25.
  2. 1 2 3 4 5 6 7 8 9 10 11 Lide, David R., ed. (2009). CRC Handbook of Chemistry and Physics (90th ed.). Boca Raton, Florida: CRC Press. ISBN   978-1-4200-9084-0.
  3. 1 2 Seidell, Atherton; Linke, William F. (1919). Solubilities of Inorganic and Organic Compounds (2nd ed.). New York: D. Van Nostrand Company. p.  169.
  4. 1 2 3 4 "Cadmium Chloride - CdCl2". chem.uwimona.edu.jm. Mona, Jamaica: The University of the West Indies. Retrieved 2014-06-25.
  5. 1 2 3 Sigma-Aldrich Co., Cadmium chloride. Retrieved on 2014-05-23.
  6. ↑ "Cadmium compounds (as Cd)". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  7. 1 2 3 NIOSH Pocket Guide to Chemical Hazards. "#0087". National Institute for Occupational Safety and Health (NIOSH).
  8. 1 2 N. N. Greenwood, A. Earnshaw, Chemistry of the Elements, 2nd ed., Butterworth-Heinemann, Oxford, UK, 1997.
  9. ↑ A. F. Wells, Structural Inorganic Chemistry, 5th ed., Oxford University Press, Oxford, UK, 1984.
  10. 1 2 H. Leligny; J. C. Monier (1974). "Structure cristalline de CdCl2.H2O" [Crystal structure of CdCl2.H2O]. Acta Crystallographica B (in French). 30 (2): 305–309. Bibcode:1974AcCrB..30..305L. doi:10.1107/S056774087400272X.
  11. 1 2 H. Leligny; J. C. Monier (1975). "Structure de CdCl2.2,5H2O" [Structure of CdCl2.2,5H2O]. Acta Crystallographica B (in French). 31 (3): 728–732. Bibcode:1975AcCrB..31..728L. doi:10.1107/S056774087500369X.
  12. 1 2 H. Leligny; J. C. Monier (1979). "Structure de dichlorure de cadmium tétrahydraté" [Structure of cadmium dichloride tetrahydrate]. Acta Crystallographica B (in French). 35 (3): 569–573. Bibcode:1979AcCrB..35..569L. doi:10.1107/S0567740879004179.
  13. ↑ F. Wagenknecht; R. Juza (1963). "Potassium cadmium chloride". In G. Brauer (ed.). Handbook of Preparative Inorganic Chemistry, 2nd Ed. Vol. 2. NY, NY: Academic Press. p. 1095.
  14. 1 2 3 4 Karl-Heinz Schulte-Schrepping; Magnus Piscator (2000). "Cadmium and Cadmium Compounds". Ullmann's Encyclopedia of Industrial Chemistry (6th ed.). p. 472. doi:10.1002/14356007.a04_499. ISBN   9783527306732.
  15. ↑ F. Wagenknecht; R. Juza (1963). "Cadmium chloride". In G. Brauer (ed.). Handbook of Preparative Inorganic Chemistry, 2nd Ed. Vol. 2. NY, NY: Academic Press. pp. 1093–4.
  16. ↑ J. March, Advanced Organic Chemistry, 4th ed., p. 723, Wiley, New York, 1992.
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