The incorrect statement is

Options

A. Formation of lead chromate
B. Formation of chromyl chloride
C. Liberation of chlorine
D. Formation of red vapours

Answer

C

Explanation

Chromyl chloride test is used to confirm the presence of `Cl^(-)` in qualitative inorganic analysis.
When a small amount of the substance (salt) is heated with conc `H_(2)SO_(4)` in presence of `K_(2)Cr_(2)O_(7)`, deep red vapours of chromyl chloride are evolved.
`NaCl_(2) + H_(2)SO_(4) to NaHSO_(4) + HCl`
`K_(2)Cr_(2)O_(7) + 2H_(2)SO_(4) to 2KHSO_(4) + 2CrO_(3) + H_(2)O`
`CrO_(3) + 2HCl to underset("chloride")underset("Chromyl")(CrO_(2) Cl_(2)) + H_(2)O`
These vapours are passed through NaOH solution and yellow coloured solution of `Na_(2)CrO_(4)` is obtained
`CrO_(2)Cl_(2) + 4NaOH to underset("yellow colour")(Na_(2)CrO_(4)) + 2NaCl + 2H_(2)O`
This yellow solution is neutralised with acetic acid and on addition of lead acetate gives a yellow ppt. of lead chromate.
`Na_(2)CRO_(4) + Pb(CH_(3)COO)_(2) to underset("yellow ppt")(PbCrO_(4)) + 2CH_(3) COONa`