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Copper(2+) chlorate hydrate (1:2:4)
Copper(II) chlorate; Cupric chlorate
3D model (JSmol)
|Density||2.26 g cm−3|
|Melting point||73 °C|
a = 12.924, b = 9.502, c = 7.233
Lattice volume (V)
Formula units (Z)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Copper(II) chlorate is a chemical compound of the transition metal copper and the chlorate anion with basic formula Cu(ClO3)2. Copper chlorate is an oxidiser. It commonly crystallizes with four molecules of water.
Copper chlorate can be made by combining a hot one molar solution of copper sulfate, with barium chlorate, which results in the precipitation of barium sulfate. When the solution is filtered, cooled and evaporated under a vacuum blue crystals form.
In 1902 A Meusser investigated solubility of copper chlorate. He found that it melted and started decomposing above 73 °C giving off chlorine.
Hexaaquacopper(II) chlorate Cu(ClO3)2•6H2O has a molecular weight of 338.54 and melts at 65 °C. Its solubility in water in g/100ml at different temperatures: 141 (0 °C) 164.4 (18 °C) 195.6 (45 °C) 332 (70 °C) g/100ml. It also dissolves in acetone and ethanol
Tetraaquacopper(II) chlorate has an orthorhombic crystal structure with cell dimensions a=12.924 b=9.502 c=7.233 Å, V = 888.3Å3, Density = 2.26 g cm-3. Each copper atom is octahedrally coordinated, surrounded by four oxygen atoms of water, and two oxygen atoms from chlorate groups, which are opposite each other. Water is closer to the copper than clorate, 1.944 Å compared to 2.396 Å, exhibiting the Jahn-Teller effect. The chlorate groups take the shape of a distorted tetrahedron. In chlorate at 298 K (25 °C) the chlorine oxygen distances are 1.498, 1.488 and 1.468 Å, with the longest being the oxygen next to copper. The ∠O-Cu-O (angle subtended at copper by oxygen atoms) is 105.2°, 108.3°, and 106.8°. At lower temperatures 233 K (−40 °C) the water molecules and copper-chlorate distance shrink.
Tetraaquacopper(II) chlorate solubility in water -31 °C 54.59 -21° 57.12 0.8° 58.51 18° 62.17 45° 66.17 59.6° 69.42 71° 76.9 g/100ml of solution A saturated water solution at 18° has a density of 1.695 g·cm−3.
Sulfur is highly reactive with copper chlorate, and it is important not to cross contaminate these chemicals, for example in pyrotechnic making.
François-Marie Chertier used tetrammine copper chlorate to colour flames blue in 1843. This material was abbreviated TACC with formula Cu(NH3)4(ClO3)2. TACC explodes on impact.
The substance became known as Chertier'c copper for use in blue coloured pyrotechnics. However its deliquescence causes a problem. Mixtures with other metal salts can yield violet or lilac colours also.
It has also been used to colour copper brown.