The dissolved copper then binds to one of the sulfate ions to make copper (II) sulfate, which lends the persulfate etchant solution a familiar blue-green tinge as etching proceeds. Another etchant ...

For example, the salt copper(II) sulfate can be prepared from the reaction of copper(II) carbonate with sulfuric acid: copper(II) carbonate + sulfuric acid → copper(II) sulfate + water + carbon ...

This slideshow shows a reversible reaction involving white anhydrous copper(II) sulfate and blue hydrated copper(II) sulfate. The equation for this is: Note that the removal of water from hydrated ...