Which of the following statements are incorrect ?

Options

A. In thiourea test for nitrite, a green coloured solution is obtained.
B. It is not necessary to carried out the chromyl chloride test in a dry test tube.
C. Suspension of `CdCO_(3)` gives black precipitate with `Na_(2)S` solution.
D. In `PbNO_(3)`, the brown ring test can be performed with its water extract.

Answer

A, B, C, D

Explanation

It is deep red colouration due to the formation of `Fe(SCN)_(3)`.
In presence of moisture, `CrO_(2)Cl_(2)+H_(2)O to H_(2)CrO_(4)+HCl`.
CdS (Yellow precipitate).
White precipitate of `PbSO_(4)` is formed and hence brown ring is not visible.