Quicklime

Coal and limestone are heated in a furnace. Quicklime is formed, but it contains ash. To get ash-free quicklime, limestone is heated with producer gas.

Uses

1.        To make slaked lime and limewater.
CaO + H₂O → Ca(OH)₂

2.        To dry ammonia.

3.        To produce limelight, an intense white light created by heated CaO.

4.        To make mortar. A thick paste of slaked lime, 3-4 parts sand, is used as mortar. On drying, CaO remains, which reacts with carbon dioxide to form calcium carbonate.
Ca(OH)₂ → CaO + H₂O
CaO + CO₂ → CaCO₃