Question

In the following scheme of reaction,

X, Y and Z respectively are :

• A. AgF, alcoholic KOH and benzene
• B. HF, aqueous KOH and Na in dry ether
• C. Hg₂F₂ alcoholic KOH and Na in dry ether
• D. CoF₂ aqueous KOH and benzene

Answer 1

The Correct Option is C

The reaction starts with C₂H₅Cl (ethyl chloride), and it undergoes the following transformations:

• X (C₂H₅F): The first step is the replacement of the chlorine atom (Cl) in ethyl chloride (C₂H₅Cl) with fluorine (F), which can be achieved by reacting it with Hg₂F₂ (Mercury(I) fluoride).
• Y (CH₂=CH₂): The second step involves the dehydrohalogenation of ethyl fluoride (C₂H₅F), which can be accomplished by using alcoholic KOH. This leads to the formation of ethylene (CH₂=CH₂).
• Z (C₄H₁₀): Finally, ethylene (CH₂=CH₂) undergoes hydrogenation with Na in dry ether, converting it into butane (C₄H₁₀).

Thus, the correct sequence of reagents for X, Y, and Z are:

• X: Hg₂F₂ (to convert C₂H₅Cl to C₂H₅F)
• Y: Alcoholic KOH (for elimination to form CH₂=CH₂)
• Z: Na in dry ether (for hydrogenation to form C₄H₁₀)

Hence, the answer is (C).

Answer 2

• X: The reaction of chlorobenzene with HF leads to the formation of fluorobenzene.
• Y: The fluorobenzene undergoes nucleophilic substitution with aqueous KOH to form phenol (C₆H₅OH).
• Z: The phenol is then reduced using Na in dry ether to form benzene