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1‑Chlorobutane is reacted with excess aqueous NaOH. Which compound is obtained as the major product?

easy MCQ 2 marks Class 12 · Chemistry · Haloalkanes and Haloarenes
  1. 1‑Butanol
  2. 2‑Butanol
  3. 1‑Butene
  4. 2‑Butene
Answer
1‑Butanol

The correct answer is 1‑Butanol — Step 4: The resulting product is 1‑butanol. This is the major product because SN2 is favoured for primary haloalkanes.

Step-by-step solution

  1. Step 1: The reaction proceeds via an SN2 mechanism as 1‑chlorobutane is a primary haloalkane.
  2. Step 2: The hydroxide ion attacks the electrophilic carbon from the backside, forming a transition state.
  3. Step 3: The C‑Cl bond breaks, leaving Cl⁻ as the leaving group.
  4. Step 4: The resulting product is 1‑butanol. This is the major product because SN2 is favoured for primary haloalkanes.
Common mistake: Confusing the product with an alkene due to misinterpreting a double bond formation

Concept tested: SN2 substitution of primary haloalkanes

Published · How this solution was prepared and checked

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