A solution containing `SCN^(-)` ions can be used to test one or more out of: `Fe^(3+),Co^(2+),Cu^(2+),Ag^(+)` and `Hg^(2+)`

Options

A. `Fe^(3+)` and `Co^(2+)` only
B. `Co^(2+),Cu^(2+),Ag^(+)` and `Hg^(2+)`
C. `Fe^(3+),Cu^(2+),Co^(2+)` and `Hg^(2+)`
D. all of the above

Answer

D

Explanation

`AgSCNdarr` (white curdy ppt. soluble in `NH_(3))`
`Cu(SCN)_(2)darr` (Black ppt)
`Hg(SCN)_(2)darr` (White ppt. soluble in excess `SCN^(-))`
`[Co(SCN)_(4)]^(2-)` (Blue colouration, but no ppt)
`[Fe(SCN)_(3)]` (Blood red colouration)