Calcium Oxide Preparation of Calcium Oxide Calcium oxide is called quick lime. It is prepared by heating limestone in a rotatory kiln at 1070-1270 K. CaCO3 ⇔ CaO + CO2 ΔH = 179.9 KJ Since the reaction is reversible, therefore, the carbon dioxide is removed as soon as it is formed to enable the reaction to proceed to completion. The temperature is not … [Read more...] about Calcium Oxide