The etching solution eventually becomes saturated with copper (II) oxide, which starts precipitating out of the solution as a blue-green solid. It takes a while to get there, though; depending on ...

This outlines one way to carry out the practical using copper(II) oxide powder and dilute sulfuric acid. Eye protection must be worn. 1. Add some dilute sulfuric acid to a small beaker.

For example: copper carbonate decomposes on heating to make solid copper oxide, which stays in the boiling tube, and carbon dioxide gas, which escapes magnesium reacts with oxygen, gained from the ...