IS IT ENDOTHERMIC OR EXOTHERMIC

Asked by ruchira_jain1 | 6th Apr, 2008, 05:41: PM

Expert Answer:

Calcium oxide is usually made by the thermal decomposition of materials such as limestone, that contain calcium carbonate (CaCO3; mineral name: calcite) in a lime kiln. This is accomplished by heating the material to above 825°C, a process called calcination or lime-burning, to liberate a molecule of carbon dioxide (CO2); leaving CaO. This process is reversible, since once the quicklime product has cooled, it immediately begins to absorb carbon dioxide from the air, until, after enough time, it is completely converted back to calcium carbonate. Calcination of limestone is one of the first chemical reactions discovered by man and was known in prehistory.

Answered by  | 28th May, 2008, 09:55: AM

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