Copper(II) hydroxide

  • Copper hydroxide
  • Kupferdihydroxid
  • Blue copper
  • Copper hydrate

Odorless bright blue powder

Fixed

3.368 g · cm -3

160 ° C decomposition from 80 ° C to water and copper (II ) oxide )

Insoluble in water

Attention

0.1 mg · m-3

1000 mg · kg -1 ( LD50, rat, oral)

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Copper ( II) hydroxide is a hydroxide salt of the copper. It is a blue solid which forms alone or in a mixture, the color pigment Bremen Blue ( also called Kalkblau ).

Occurrence

Of course the copper ( II) hydroxide is available as part of the green patina of copper, which is a mixture of copper hydroxide and copper (II ) carbonate. A rare pure copper (II ) hydroxide mineral is Spertiniit.

Production and representation

Cupric hydroxide can be prepared by the reaction of copper salts with alkalis. Typically copper sulphate pentahydrate is dissolved in water to and reacted with cooling by addition of sodium hydroxide to copper hydroxide and sodium sulfate.

Alternatively, copper may also be produced by the electrochemical conversion of copper into the water.

Properties

Copper ( II) hydroxide is insoluble in cold water. In concentrated alkali metal hydroxide solutions, the compound is soluble. Here, hydroxo form as the deep blue [Cu ( OH) 4] 2 -. Likewise, freshly precipitated copper (II ) hydroxide is soluble in ammonia solution to form the complex compound tetrammine copper (II ) hydroxide. Reaction with mineral acids gives the corresponding copper ( II) salts.

Upon heating decays ( freshly precipitated ) copper (II ) hydroxide to copper ( II ) oxide and water.

Upon careful drying ( 100 ° C) obtained virtually anhydrous copper (II ) hydroxide in crystallized form.

Use

Copper ( II) hydroxide is used as the

  • Pesticide ( fungicide in the fruit, wine, hops, vegetables, and bananas are grown )
  • For the production of pigments (eg from Peligotblau, which is lightfast under artificial light )
  • For the preparation of the well-known under the name of Swiss reagent ammonia solution, which serves as a reagent and the dissolving of rayon.
  • For the production of cuprammonium rayon
  • For the manufacture of mordants, ship bottom paints, catalysts
CAS registry number Dangerous Substances Directive (67/548/EEC) Lye Electrochemistry Schweizer's reagent
131794
de