Question

`K_(4)[Fe(CN)_(6)]` is used to detect
A. `Cu^(2+)`
B. `As^(3+)`
C. `Zn^(2+)`
D. `Fe^(3+)`

Answer 1

Correct Answer - A,C,D
`(A) 2Cu^(2+)+K_(4)[Fe(CN)_(6)]rarrunderset(["chocolate brown ppt."])(Cu_(2)[Fe(CN)_(6)]+4K^(+))`
`(C ) 2Zn^(2+)+K_(4)[Fe(CN)_(6)]underset(("bluish white ppt."))(Zn_(2)[Fe(CN)_(6)]+4K^(+))`
`(D)4Fe^(3+)+3K_(4)[Fe(CN)_(6)]rarrunderset(("prussian blue"))(Fe_(4)[Fe(CN)_(6)]_(3))+12K^(+)`