The compound B is :
`CH_(3)CH_(2)COOH overset(Cl_(2))underset(red P)rarrAoverset(Alc. KOH)rarrB`

End product of the following reaction is CH_(3)CH_(2)COOH overset(Cl_(2))underset(red P)to overset("alcoholic KOH")to

CH_(3)CH_(2)COOH overset(Cl_(2)//Fe)rarr X overset(KOH(alc))rarrY compound Y is