What is chromyl chloride test ? Give equation

Explanation

(I ) When potassium dichromate is heated with any chloride salt in the presence of conc. `H_(2) SO_(4)` orange rad vapours of chromyl chloride `(CrO_(2)Ci_(2))` is evolved.
(ii) This reaction is used to confirm the presence of chloride ion in inorganic qualitative analysis .
`K_(2) Cr_(2) O_(7) + 4NaCI+ 6H_(2) SO_(4) to`
`2KHSO_(4) + 4NaHSO_(4) + 2CrO_(2) CI_(2) + 3H_(2) O`
(iii) The chromyl chloride vapours are dissolved in sodium hydroxide solution and then acidified with acetic acid and treated with lead acetate . A yellow precipitate of lead chromate is obtained.
`CrO_(2) CI_(2) +4 NaOH to `
`Na_(2) CrO_(4) + 2NaCI + 2H_(2) O`
`Na _(2) CrO_(4) + (CH_(3) COO ) _(2) Pb to `
`underset(Leadchromate )(PbCrO) + 2CH_(3) COONa`