question_answer

For the following reactions :-      [NEET - 2016]

\[~C{{H}_{3}}C{{H}_{2}}C{{H}_{2}}Br\text{ }+\text{ }KOH\to \]\[C{{H}_{3}}CH=C{{H}_{2}}+KBr\text{ }+\text{ }{{H}_{2}}O\]

Which of the following statements is correct?

A) and are elimination reaction and is addition reaction

B) is elimination, is substitution and is addition reaction

C) is elimination, and are substitution reactions

D) is substitution, and are addition reaction

Correct Answer: B

Solution :

[b]

\[C{{H}_{3}}C{{H}_{2}}C{{H}_{2}}Br+KOH\to C{{H}_{3}}CH\] \[=C{{H}_{2}}+KBr+\text{ }{{H}_{2}}O\] breaking of \[2\sigma \] bonds and formation of 1 \[1\pi \] bond so it is an example of elimination reaction.

replacement of \[B{{r}^{-}}\] by \[\text{O}{{\text{H}}^{\text{--}}}\] is substitution reaction

breaking of \[1\pi \] bond and formation of \[2\sigma \] bonds is addition reaction