Identify the reagents A and B respectively in the following reactions.
`CH_(5)COOHoverset(A)toCH_(5)COCIoverset(B)toC_(5)CHO`

Options

A. `SOCI_(2),H_(2)//Pd-BaSO_(4)`
B. `H_(2)//Pd-BaSO_(4),SOCI_(2)`
C. `SOCI_(2),H_(2)O_(2)`
D. `SOCI_(2),O_(5)O_(4)`

Answer

A

Explanation

The sequence of reaction is
`underset("Acetic acid")(CH_(3)COOH)overset(SOCI_(2))(to)underset("Acetyl chloride")(CH_(3)COCI)overset(H_(2)//Pd-BaSO_(4))(to)underset("Acetaldehyde")(CH_(3)CHO)`
Hence, `A=SOCI_(2), B=H_(2)//Pd-BaSO_(4)`