Question

Exam Which of the following is the most stable alkene? АМ 26 Multiple Choice от Оп

Answer 1

We know that substituted alkenes are more stable than unsubtituted alkenes due to hyperconjugation (delocalisation of electrons in a sigma bond and its interaction with electrons in an adjacent p or pi orbital which could be empty or partially filled which results in overall stabilisation of the molecule). So a mono substituted alkene is less stable than a disubstituted alkene which is less stable than trisubstituted and tetrasubstituted alkenes. We can see that (II) is a mono substituted alkene with one substitutent attached to one of the carbons forming a double bond. (I) is a disubstituted alkene with a substituent on each of the carbons forming a double bond. (III) and (IV) are trisubstituted amd tetrasubstituted alkenes with respectively three and four substituents on the carbons forming the double bond. So the most stable alkene is (IV). Correct answer is option (IV).