Question

For the following reactions:
Which of the following statements is correct?

• A. (a) is elimination, (b) and (c) are substitution reactions.
• B. (a) and (b) are elimination reactions and (c) is addition reaction.
• C. (a) is elimination, (b) is substitution and (c) is addition reaction.
• D. (a) is substitution, (b) and (c) are addition reactions.

Answer 1

Answer: (C)

(a) is elimination,
When an alkyl bromide is heated with alcoholic $KOH$ solution, a molecule of HBr is eliminated to form $C=C$ double bond.
(b) is substitution
When secondary alkyl bromide is heated with aqueous $KOH$, bromine atom is substituted with $-OH$ group.
(c) is addition reaction
A molecule of bromine is added across $C=C$ double bond.