Which of the following is incorrect about the carbonates of alkaline earth metals ?

Options

A. They are insoluble in water.
B. They are obtained as white precipitates when calculated amount of `CO_(2)` is passed through the solution of group 2 hydroxides.
C. They are precipitated when sodium or ammonium carbonate solution is added to an aqueous solution of water soluble salt of group 2 elements.
D. All the carbonates are ionic.

Answer

D

Explanation

All the carbonates are ionic, but `BeCO_(3)` is unusual because it contains the hydrated `[Be(H_(2)O)_(4)]^(2+)` rather than `Be^(2+)`
(2) `M(OH)_(2)(aq.)+CO_(2)(g)toMCO_(3)(s)+H_(2)O(l)`
(3) `CaCl_(2)(aq.)+Na_(2)CO_(3)(aq.)toCaCO_(3)(s)+2NaCl(aq.)`
Bryllium carbonate is prone to hydrolysis as it contains the hydrated ion `[Be(H_(2)O)_(4)]^(2+)` rather than `Be^(2+)` hence it can be precipitated only in an atmosphere of `CO_(2)`.
`BeCO_(3)+4H_(2)Ounderset("Presence of "CO_(2))overset("Absence of "CO_(2))hArr[Be(H_(2)O)_(4)]^(2+)+CO_(3)^(2-)`