How can I make the copper get white by any salt or acit?I have some test on the copper

The copper sulfate compound (CuSO4) is a salt and it is
used to illustrate the inorganic chemical reaction called mineral
hydration.

The pentahydrate copper sulfate usually has a
blue color.

When pentahydrate copper sulfate is heated, to
prove the exothermic reaction, the water inside evaporates, leaving behind a new
anhydrous form whose color is white.

If water is added to
the new anhydrous form, it will become the original blue pentahydrate copper
sulfate.