Exemplar Problems

Problem 5 : Draw the structural formula of the major product formed when ethene undergoes the following reactions:

(a) With HBr in the presence of peroxide (b) With H₂SO₄ in the presence of HgSO₄ (c) With KMnO₄ in alkaline medium (d) With Cl₂ in the presence of sunlight

Solution :

(a) With HBr in the presence of peroxide: [ \text{CH}_2 = \text{CH}_2 + \text{HBr} \rightarrow \text{CH}_3 - \text{CH}_2 - \text{Br} ]

(b) With H₂SO₄ in the presence of HgSO₄: [ \text{CH}_2 = \text{CH}_2 + \text{H₂SO₄} \rightarrow \text{CH}_3\text{CHO} ]

(c) With KMnO₄ in alkaline medium: [ \text{CH}_2 = \text{CH}_2 + \text{KMnO}_4 \rightarrow \text{CO}_2 + \text{MnO}_2 + \text{KOH} ]

(d) With Cl₂ in the presence of sunlight: [ \text{CH}_2 = \text{CH}_2 + \text{Cl}_2 \rightarrow \text{CH}_2\text{ClCH}_2 ]