Select all correct statements about the chromyl chloride test.

AUnder the same conditions $NaBr$ gives red $CrO X_{2} Br X_{2}$ vapours.
B $HgCl X_{2}$ fails to give the test because, being covalent, it does not supply chloride ions.
CSolid $NaCl$ gives orange-red $CrO X_{2} Cl X_{2}$ vapours when warmed with $K X_{2} Cr X_{2} O X_{7}$ and conc. $H X_{2} SO X_{4}$ .
DChromium stays in the +6 oxidation state in going from dichromate to $CrO X_{2} Cl X_{2}$ .

Answer: B, C, D

K X_{2} Cr X_{2} O X_{7} + 4 NaCl + 6 H X_{2} SO X_{4} 2 CrO X_{2} Cl X_{2} + 4 NaHSO X_{4} + 2 KHSO X_{4} + 3 H X_{2} O

has no change in oxidation states, and covalent

HgCl X_{2}

does not ionise. Bromide is simply oxidised to

Br X_{2}

(no chromyl bromide test exists), so the last statement is false.