Which of the following pair (s) of ions would be expected to form precipitate when dilute solutions are mixed?

Options

A. `NH_(4)^(+),[Co(NO_(2))_(6)]^(3-)`
B. `NH_(4)^(+),CO_(3)^(2-)`
C. `Fe^(3+),OH^(-)`
D. `Ba^(2+),SO_(4)^(2-)`

Answer

A, B, C

Explanation

`(NH_(4))_(2)CO_(3)` is soluble. `(NH_(4))_(3) [Co(NO_(2))_(6)]darr` (yellow), `Fe(OH)_(3)darr` (Reddish brown), `BaSO_(4)darr` (white).