Copper(II) phosphate

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Freshly ground copper(II) phosphate intended for use in blue paint

Copper(II) phosphate, or cupric phosphate, is a chemical compound with the formula Cu3(PO4)2. It is a light blue powdery compound that is insoluble in water.



Copper(II) phosphate will react with strong acids acids, such as sulfuric acid to produce the corresponding copper salt and phosphoric acid.


Copper(II) phosphate is a light blue, powdery substance that is insoluble in water and ethanol, but soluble in ammonia and mineral acids.


Copper(II) phosphate is usually unavailable for sale as it has very few applications. It is however extremely easy to prepare with OTC chemicals.


Freshly precipitated and filtered copper(II) phosphate

Copper(II) phosphate can be prepared by combining copper(II) sulfate and trisodium phosphate in a 3:2 molar ratio.

3 CuSO4 (aq) + 2 Na3PO4 (aq) → 2 Cu3(PO4)2 (s) + 3 Na2SO4 (aq)

A different preparation involves reacting copper carbonate with phosphoric acid:

3 Cu2CO3(OH)2 + 4 H3PO4 → 2 Cu3(PO4)2 + 3 CO2 + 9 H2O

Monoammonium phosphate also works for this preparation.


  • Copper compounds collection
  • Paint pigments
  • Copper (II) phosphate can be reduced to copper phosphide, which can be used to isolate elemental phosphorous by heating it: 4 Cu3P2 → 4 Cu3P + P4



Like all copper compounds, copper(II) phosphate is mildly toxic, but since it is insoluble it is less of a concern than soluble compounds.[1]


Copper(II) phosphate should be stored in closed bottles.


Copper phosphate should be disposed just like any other copper compound.



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