Question

A sodium salt on treatment with `MgCl_(2)` gives white precipitate only on heating. The anion of the sodium salt is `:`
A. `HCO_(3)^(-)`
B. `CO_(2)^(2-)`
C. `NO_(3)^(-)`
D. `SO_(4)^(-)`

Answer 1

Correct Answer - A
The anion is `HCO_(3)^(-)` and it reacts with `MgCI_(2)` as follows:
`2NaHCO_(3) + MgCI_(2) to Mg (HCO_(3))_(2) + 2NaCI`
`Mg(HCO_(3))_(2) overset("Heat")(to) MgCO_(3) + CO_(2) + H_(2)O`