Question

Diphenylamine reagent gives a deep blue colour with a solution. It contains
A. `Sn^(2+)`
B. `NO_(2)^(-)`
C. `NO_(3)^(-)`
D. `Fe^(3+)`

Answer 1

`NO_(2)^(-),NO_(3)^(-)` and `Fe^(3+)` being oxidising agents oxidise diphenylamine giving deep blue colour.