Element A burns in nitrogen to give an ionic compound B. Compound B reacts with water to give C and D. The solution of C becomes milky on bubbling carbon dioxide . The element A is

Options

A. Li
B. Mg
C. Ca
D. Be

Answer

C

Explanation

Carbon dioxide turns only lime water milky. Thus. The compound C must be `Ca(OH)_(2)` and the element A must be Ca. The reactions are as follows.
`underset(A) (3Ca) + N_(2) to underset(B)(Ca_(3)N_(2))`
`underset(B)(Ca_(3)N_(2))+ 6H_(2)O to underset(C)(3Ca(OH)_(2))+ underset(D) (2NH_(3))`
`underset(C)(Ca(OH)_(2)) + CO_(2) to underset("Milky")(CaCO_(3)) + H_(2)O`