Copper

Copper is a chemical element in the periodic table that has the symbol Cu and atomic number 29.

Tests for copper²⁺ ion

Add aqueous sodium hydroxide. A blue precipitate of copper(II) hydroxide should form, by the displacement of the copper ions by sodium ions.

Related Topics:
Sodium hydroxide - Copper(II) hydroxide - Sodium - Ions

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Ionic equation:

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:Cu2+(aq) + 2OH-(aq) -> Cu(OH)2 (s)

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Add aqeuous ammonia. A precipitate should form, which then dissolves upon adding excess ammonia, to form an ammonia complex, tetraaminecopper(II).

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Ionic equation:

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:Cu2+(aq) + 4NH3 (aq) -> Cu(NH3)42+(aq)

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