Question

A chemical A is used for the preparation of washing soda to recover ammonia. When `CO_(2)` is bubbled through an aqueous solution of A, the solution turns milky. It is used in white washing due to disinfectant nature what is the chemical formula of A?
A. `Ca(HCO_(3))_(2)`
B. `CaO`
C. `Ca(OH)_(2)`
D. `CaCO_(3)`

Answer 1

Correct Answer - C
To recover `NH_(3)` in Solvay ammonia soda process `Ca(OH)_(2)` is used.
`2NH_(4)CI + Ca(OH)_(2) rarr 2NH_(3)+CaCI_(2)+2H_(2)O`
On passing `CO_(2)` through `Ca(OH)_(2)`, it turns milky due to the formation of `CaCO_(3)`.
`Ca(OH)_(2) +CO_(2) rarr CaCO_(3) darr +H_(2)O`
`Ca(OH)_(2)` is used for white washing.