Uploaded December 2020 | Updated September 2026, 1 hour ago

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This reaction shows the thermal decomposition of copper(II) carbonate:

CuCO3 = CuO + CO2
green copper oxide is decomposed to black copper oxide and carbon dioxide. The carbon dioxide is bubbled through lime water (calcium hydroxide solution) turning it milky white (calcium carbonate precipitate)

Ca(OH)2 + CO2 = CaCO3 + H2O