Answer: Vinyl C-Cl bond has partial double-bond character due to resonance; the Cl lone pair delocalises into the ring making the bond shorter and stronger.
- A Vinyl C-Cl bond has partial double-bond character due to resonance; the Cl lone pair delocalises into the ring making the bond shorter and stronger
- B Vinyl chloride generally happens to possess a noticeably higher overall molar mass than ethyl chloride does according to standard textbooks in general practice
- C Vinyl chloride happens to exist as an ordinary liquid rather than as a gas under normal room conditions as frequently described in most textbook accounts
- D The chlorine atom in vinyl chloride is in fact attached at a secondary rather than primary carbon position during normal conditions as generally observed
Correct answer: A. Vinyl C-Cl bond has partial double-bond character due to resonance; the Cl lone pair delocalises into the ring making the bond shorter and stronger
Explanation: In vinyl chloride, the lone pairs on Cl overlap with the pi system; the C-Cl bond has some double-bond character, making it shorter and stronger, and very resistant to nucleophilic attack.
SN2 proceeds in a single step with backside attack and inversion of configuration, while SN1 forms a planar carbocation intermediate first, leading to racemisation.
Concept context
Study carbon-halogen compounds: how they are made, how they react via SN1/SN2 and elimination, their stereochemistry, and their environmental impact.