Answer:
Step-by-step explanation:
Benzaldehyde can be prepared from toluene through Etard reaction .In this reaction benzaldehyde is treated with reagent chromyl chloride ( CrO₂Cl₂ ) which oxidises it to benzaldehyde.
to form benzaldehyde .
CrO₂Cl₂
C₆H₅CH₃ -----------------------> C₆H₅CHO