(a)
C 2 H 4 ethene + Cl 2 → [inert solvent] CCl 4 C 2 H 4 Cl 2 1,2, dichloroethane [ethylene chloride] \underset{\text{ ethene}}{\text{C}_2\text{H}_4} + \text{Cl}_2 \xrightarrow[\text{[inert solvent]}]{\text{CCl}_4} \underset{\text{1,2, dichloroethane [ethylene chloride]}}{\text{C}_2\text{H}_4\text{Cl}_2} ethene C 2 H 4 + Cl 2 CCl 4 [inert solvent] 1,2, dichloroethane [ethylene chloride] C 2 H 4 Cl 2
Product formed is 1,2, dichloroethane [ethylene chloride]
C 2 H 4 ethene + Br 2 → [inert solvent] CCl 4 C 2 H 4 Br 2 1,2, dibromooethane [ethylene bromide] \underset{\text{ ethene}}{\text{C}_2\text{H}_4} + \text{Br}_2 \xrightarrow[\text{[inert solvent]}]{\text{CCl}_4} \underset{\text{1,2, dibromooethane [ethylene bromide]}}{\text{C}_2\text{H}_4\text{Br}_2} ethene C 2 H 4 + Br 2 CCl 4 [inert solvent] 1,2, dibromooethane [ethylene bromide] C 2 H 4 Br 2
Product formed is 1,2, dibromooethane [ethylene bromide]
(b) Conditions for hydrogenation of ethene : finely divided catalyst, such as platinum or palladium at ordinary temperature or nickel at 200°C . Main product formed is ethane .
C 2 H 4 ethene + H 2 → 200 ° C Nickle C 2 H 6 ethane \underset{\text{ ethene}}{\text{C}_2\text{H}_4} + \text{H}_2 \xrightarrow[200\degree\text{C}]{\text{Nickle}} \underset{\text{ethane}}{\text{C}_2\text{H}_6} ethene C 2 H 4 + H 2 Nickle 200° C ethane C 2 H 6
