Cupric ammonia complex chloride

Copper forms practically aU its stable compounds in -i-l and +2 valence states. The metal oxidizes readily to -i-l state in the presence of various com-plexing or precipitating reactants. However, in aqueous solutions +2 state is more stable than -i-l. Only in the presence of ammonia, cyanide ion, chloride ion, or some other complexing group in aqueous solution, is the +1 valence state (cuprous form) more stable then the +2 (cupric form). Water-soluble copper compounds are, therefore, mostly cupric unless complexing ions or molecules are present in the system. The conversion of cuprous to cupric state and metalhc copper in aqueous media (ionic reaction, 2Cu+ — Cu° -i- Cu2+) has a Kvalue of 1.2x106 at 25°C. 

Ammino-cupric Bromides.—Cupric bromide, like euprie chloride, absorbs ammonia gas, forming complex ammino-compounds. The following ammines of cupric bromide have been described Hexammino-cupric bromide, [Cu(NH3)6]Br2 pentammino-cupric bromide, [Cu(NH3)5]Br2 diammino-cupric bromide, [Cu(NTI3)2]Br2 and decammino-tricupric bromide, [Cu3(NH3)10]Br8. 

The type a) expl sometimes with a report, spades and flashes to form black CuO. It could be fired by a drop of HNO,. The ex-plosibility of this type of acetylide is greater than thatof cuprous acetylide. This type includes most acetylides, formed from the more common cupric salts, such as die chloride, sulfate and nitrate, and those formed from copper org salts made alkaline with alkaliesother than ammonia, or also with ammonia, provided insufficient ammonia is present to retain all the Cu as a complex salt... 

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