When limestone powder (calcium carbonate, CaCO3) is heated strongly, it decomposes to form calcium oxide (CaO), also known as quicklime, and carbon dioxide gas (CO2).
This process is called thermal decomposition or calcination. The chemical equation representing this reaction is:
CaCO3(s) → CaO(s) + CO2(g)
Here's a breakdown:
- Limestone (CaCO3): The starting material, also known as calcium carbonate, exists as a solid.
- Heating: A high temperature is required to initiate the decomposition reaction.
- Calcium Oxide (CaO): One of the products, commonly called quicklime, exists as a solid. Quicklime is a crucial ingredient in the production of cement, mortar, and various other industrial processes.
- Carbon Dioxide (CO2): The other product is carbon dioxide, a colorless and odorless gas.
Because heat is required for this reaction to proceed, it's classified as an endothermic reaction.
In summary, heating limestone powder results in the formation of quicklime (calcium oxide) and carbon dioxide gas.
