Copper(I) chloride

Copper(I) chloride

Names
IUPAC name Copper(I) chloride
Other names Cuprous chloride
Identifiers
CAS Number	7758-89-6 Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:53472 Y
ChemSpider	56403 Y
ECHA InfoCard	100.028.948
EC Number	231-842-9
PubChem	62652
RTECS number	GL6990000
InChI InChI=1S/ClH.Cu/h1H;/q;+1/p-1 Y Key: OXBLHERUFWYNTN-UHFFFAOYSA-M Y InChI=1/ClH.Cu/h1H;/q;+1/p-1 Key: OXBLHERUFWYNTN-REWHXWOFAC
SMILES Cl[Cu]
Properties
Chemical formula	CuCl
Molar mass	98.999 g/mol
Appearance	white powder, slightly green from oxidized impurities
Density	4.145 g/cm3
Melting point	426 °C (799 °F; 699 K)
Boiling point	1,490 °C (2,710 °F; 1,760 K) (decomposes)
Solubility in water	0.0062 g/100 mL (20 °C)
Solubility product (Ksp)	1.72 x 10−7
Solubility	insoluble in ethanol acetone; soluble in concentrated HCl, NH4OH
Magnetic susceptibility (χ)	-40.0·10−6 cm3/mol
Refractive index (nD)	1.930
Structure
Crystal structure	Zinc blende structure
Hazards
Safety data sheet	JT Baker
EU classification (DSD)	Harmful (Xn) Dangerous for the environment (N)
R-phrases	R22, R50/53
S-phrases	(S2), S22, S60, S61
NFPA 704	0 3 0
Flash point	Non-flammable
Lethal dose or concentration (LD, LC):
LD50 (median dose)	140 mg/kg
US health exposure limits (NIOSH):
PEL (Permissible)	TWA 1 mg/m3 (as Cu)
REL (Recommended)	TWA 1 mg/m3 (as Cu)
IDLH (Immediate danger)	TWA 100 mg/m3 (as Cu)
Related compounds
Other anions	Copper(I) bromide Copper(I) iodide
Other cations	Copper(II) chloride Silver(I) chloride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

Copper(I) chloride, commonly called cuprous chloride, is the lower chloride of copper, with the formula CuCl. The substance is a white solid sparingly soluble in water, but very soluble in concentrated hydrochloric acid. Impure samples appear green due to the presence of copper(II) chloride.

Copper(I) chloride was first prepared by Robert Boyle in the mid-seventeenth century from mercury(II) chloride ("Venetian sublimate") and copper metal:

In 1799, J.L. Proust characterized the two different chlorides of copper. He prepared CuCl by heating CuCl₂ at red heat in the absence of air, causing it to lose half of its combined chlorine followed by removing residual CuCl₂ by washing with water.

An acidic solution of CuCl was formerly used for analysis of carbon monoxide content in gases, for example in Hempel's gas apparatus. This application was significant during the time that coal gas was widely used for heating and lighting, during the nineteenth and early twentieth centuries.

Copper(I) chloride is produced industrially by the direct combination of copper metal and chlorine at 450–900 °C:

Cu + 0.5 Cl₂ → CuCl

Copper(I) chloride can also be prepared by reducing copper(II) chloride, e.g. with sulfur dioxide:

2 CuCl₂ + SO₂ + 2 H₂O → 2 CuCl + H₂SO₄ + 2 HCl

Many other reducing agents can be used.

Copper(I) chloride is a Lewis acid, which is classified as soft according to the Hard-Soft Acid-Base concept. Thus, it tends to form stable complexes with soft Lewis bases such as triphenylphosphine:

Although CuCl is insoluble in water, it dissolves in aqueous solutions containing suitable donor molecules. It forms complexes with halide ions, for example forming H₃O⁺ CuCl₂⁻ with concentrated hydrochloric acid. It is attacked by CN⁻, S₂O₃²⁻, and NH₃ to give the corresponding complexes.