A bromide ion does not interfere with the chromyl chloride test because when a bromide is present:
a. Br2 is liberated, which leaves the NaOH solution colourless
b. CrO2Br2 formed does not volatilise as CrO2Cl2 does
c. CrO2Br2 does not react with NaOH
d. no gaseous substance containing bromine is produced