Copper(II)-ammonium sulfate

From Crystal growing

   Copper(II)-ammonium sulfate   
Names: Copper ammonium sulfate
copper Tutton's salt

Formula: (NH4)2Cu(SO4)2 (anhydrous)
(NH4)2Cu(SO4)2 · 6H2O (hexahydrate)
SMILES: [O-]S(=O)(=O)[O-].[O-]S(=O)(=O)[O-].[Cu+2].[NH4+].[NH4+]
Molar mass: 291.746 g/mol (anhydrous)
399.835 g/mol (hexahydrate)
Density: 1.921 g/cm3 (hexahydrate)
Crystal system: monoclinic (hexahydrate)
a=6.31 Å, b=12.38 Å, c=9.22 Åα=90°, β=106.16°, γ=90°

Color: light-blue
Stability: stable (hexahydrate)
hygroscopic (anhydrous)
Hardness: relatively strong


Inorganic compound, double salt of transitional metal copper, ammonium ion and inorganic sulfuric acid. Due to serious Jahn-Teller effect and random directions of the copper ion, this salt is very opaque. Small crystals have shape resembling that of sodium chloride with a white X at the center while big crystals tend to be irregular. From water solutions crystallizes as hexahydrate.


Reaction between copper(II) and ammonium sulfates

Chemical equation:

(NH4)2SO4 + CuSO4 = (NH4)2Cu(SO4)2

For preparation of 100.00g of copper(II)-ammonium sulfate hexahydrate а 62.45g of copper(II) sulfate pentahydrate and 33.05g of ammonium sulfate is required.

Dissolve compounds in hot water apart and then mix solutions into one container with intense stirring. Cooling or evaporation of a solution will cause double salt crystallyzation. Filter precipitate and wash it wish small amount of ethanol or acetone, then filter the solution and use it for crystal growing.


Tutton's salts are isomorphous with each other. Mixing with the zinc salt can greatly enhance the transparency and regularize the shape.

Storage conditions

Store in its original form or under several layers of varnish at average humidity and room temperature. Do not store in matchboxes or cotton wool and do not heat.


Insoluble in ethanol and acetone.