Compound 'A' when dissolved in water gives compound 'B' which is used in white washing. Compound 'B' reacts with `CO_2` to form a white preciptate of compound 'C'. Identify compounds 'A', 'B' and ,C'. Also write the equations involved.

Explanation

`.A.underset("Exothermic reaction")overset(+H_(2)O)(to)" " underset("Used for White washing")(.B.) , B+CO_(2) to underset("White ppt.")(.C.)`
Slaked lime `[Ca(oH)_(2)]` is used for white washing. It is obtained when quick lime, CaO reacts with water.
`underset("Quick lime"(A))(CaO)+H_(2)O to underset("Calcium hydroxide(Slaked lime)(B)")(Ca(OH)_(2))+" Heat "`
So .A. is CaO and .B. is `Ca(OH_2)`.
`underset((B))(Ca(OH)_(2(aq)))+CO_(2(g)) to underset("Calcium carbonate(White ppt.)(C)")(CaCO_(3(s)))+" H_(2)O_((l))`
.C. is `CaCO_(3)`.