## Copper sulfate

**Formula**
 
$CuSO4.5H2O$

**Synonyms**
 
Copper sulfate, cupric sulfate, blue vitriol, bluestone, Chalcanthite

**Description**
 
Copper(II) sulfate is the chemical compound with the formula CuSO4. This salt exists as a series of compounds that differ in their degree of hydration. The anhydrous form is a pale green or gray-white powder, whereas the pentahydrate, the most commonly encountered salt, is bright blue. It is used as a blue flame colorant in ammonium perchlorate based compositions where it sometimes substitutes the more expensive Paris green. The resulting blue color is almost as good as with the latter. It is not easily scattered and not anywhere near as toxic. Small amounts of copper sulfate are contained even in mineral waters. Copper sulfate can be used as a minor oxidizer and in combination with finely powdered Mg can be used as a pressure sensitive composition due to the waters of hydration (this is very unstable though). Copper sulfate is not good for colored flash experimentation,though.

**Sources** 

Pyro suppliers, paint stores, drugstore (in Europe at least it can be bought to keep your pool clean, works great for that purpose) is also available as a copper patina for stained glass. (must be evaporated as it is in a solution) may also be available as a fungicide for gardens depending upon the demographic in your area.

**Synthesis**

Copper sulfate can be produced by the use of a "piranha" solution.

H2SO4+H2O2+Cu--->CuSO4x5H2O

  
Copper sulfate can also be synthesized by electrolysis of a solution of sulfuric acid with a copper anode, which forms H2 gas at the cathode and CuSO4 by the following reaction.

Cu(s)+2H+(aq)--->Cu2+(aq)+H2 (g)

The sulfate from the sulfuric acid is unchanged by this reaction, giving an end product of a solution of CuSO4. This must be done with an excess of sulfuric acid, since when the acid is depleted this will begin to form a mixture of Cu(OH)2 and CuO.

**Hazards**

N, Xn, Xi

Due to its acidic nature it must not be used together with chlorates or phosphorus. Nonetheless it can be used with perchlorates or nitrates. Copper sulfate is toxic and used in lakes to kill sea weed.
