Chapter 8, Problem 14CTQ

Interpretation Introduction

Interpretation: Reason for reaction to occur by electron movement in alkene shown below rather than electron movement in opposite direction should be explained.

  

Concept introduction: The carbon-carbon double bond in alkene consists of a strong $\sigma$ bond (formed by overlap of $s{p}^2$ hybridized orbital on each carbon) and a weak $\pi$ bond (formed by overlap of pure $p$ orbital on each carbon). Due to unsaturation, alkene shows addition reaction where the double bond provides loosely held $\pi$ electrons and is readily attacked by any electron deficient group like ${\text{H}}^{+}$ ions released from acids. The loosely held $\pi$ electrons are present, therefore, behave as base though weak one.