Description of experiment
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Needed compounds:
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hydroxyl amine sulfate : (NH3OH)2 SO4
sodium hydroxide : NaOH
ethyl acetate : CH3C(O)OCH2CH3
copper sulfate penta hydrate : CuSO4 . 5H2O
Class:
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elem=Cu
organic
redox
Summary:
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Copper (II) forms a coordination compound with ethyl acetate, which has
reacted with hydroxyl amine.
Description:
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Add some ethyl acetate to water and shake: Most of the liquid dissolves in
the water, but not all.
Add some NaOH: The solid dissolves and the ethyl acetate now also dissolves.
Add some solid (NH3OH)2SO4: The solid dissolves, no visible changes can be
observed. The odour of the liquid changes.
Add part of this liquid to a solution of CuSO4.5H2O: The liquid becomes dark
green and turbid. A precipitate is formed.
Add the remaining part of the liquid: Now the precipitate dissolves again,
and the liquid becomes deep blue (similar to the color of [Cu(NH3)4]2+)
and clear. Slowly, however, the intensity of the blue color fades away.
Apparently not all of the hydroxyl amine has reacted and this reduces the
blue copper (II) complex to a colorless copper (I) complex.