Aq. Solution of
the cation(s) present in 'X' is/are:

Options

A. `NH_(4)^(+)`
B. `Na^(+)`
C. `Mg^(2+)`
D. `K^(+)`

Answer

A, D

Explanation

`3K^(+)+Na_(3)[Co(NO_(2))_(6)] to underset("yellow")(K_(3)[Co(NO_(2))_(6)darr)+3Na^(+)]`
`Na^(+) and Mg^(2+)` do not give test.