Which of the following reaction occur during calcination ?

Options

A. `CaCO_(3) to CaO+CO_(2)`
B. `2FeS_(2)+(11)/(2)O_(2) to Fe_(2)O_(3)+4SO_(2)`
C. `Al_(2)O_(3).xH_(2)O to Al_(2)O_(3)+xH_(2)O`
D. `ZnS+(3)/(2)O_(2) to ZnO+SO_(2)`

Answer

A, C

Explanation

(a,c) Calcination involves heating of the ore below its melting point in the absence of air or in limited supply of air. Oxygen containing ore likes oxide, hydroxide and carbonate are calcined. Thus, the following reaction occur during calcination.
`CaCO_(3) overset(Delta) rarr CoO+CO_(2)`
`Al_(2)O_(3).xHH_(2)O overset(Delta) rarr Al_(2)O_(3)+xH_(2)O`