Copper sulphate is a chemical salt most commonly seen in the form of vivid blue crystals. Although toxic, it is regularly used in chemistry education as it is highly reactive with a number of substances. Copper carbonate is the substance responsible for the green tinge on weathered copper, bronze or brass and is used as a pigment in some paints. It can be converted to copper sulphate through the addition of sulphuric acid, producing carbon dioxide and water.
Place the copper carbonate in the bottom of the glass beaker.
Pour the sulphuric acid into the beaker, adding only a few drops at a time and stirring vigorously. The mixture will begin to effervesce as carbon dioxide gas is produced.
Continue to add the remaining acid and stir the mixture until no more bubbles are being produced. The chemical reaction is now complete and the beaker will contain a clear blue liquid - this is copper sulphate. To grow copper sulphate crystals, simply let the solution evaporate for a few days.
The chemical equation for the reaction is: H2SO4 + CuCO3 --> CuSO4 + H2O + CO2.
Both copper carbonate and copper sulphate are toxic. Wear gloves throughout the process and handle with care.