Question

Alkenes are called olefins? Give reason.

Answer 1

1. The organic compounds containing Carbon ($\mathrm{C}$) atoms have a double bond between two carbon atoms are called unsaturated hydrocarbons.
2. Olefin is a Carbon ($\mathrm{C}$) -Hydrogen ($\mathrm{H}$) molecule with one or more pairs of carbon atoms joined by a double bond.
3. Alkenes are also called olefins because it reacts with Chlorine $\left({\mathrm{Cl}}_2\right)$ gas to form oily liquids.
4. Example: The reaction of Ethene $\left({\mathrm{C}}_2{\mathrm{H}}_4\right)$ with Chlorine $\left({\mathrm{Cl}}_2\right)$ gas forms the$(1,2-\mathrm{dichloroethane})$.
5. The product $(1,2-\mathrm{dichloroethane})$ is formed is oily in nature.
6. The chemical reaction of Ethene with Chlorine gas is written as:

$$\begin{gathered} {\mathrm{CH}}_2={\mathrm{CH}}_2+\mathrm{Cl}-\mathrm{Cl}\to {\mathrm{CH}}_2\left(\mathrm{Cl}\right){\mathrm{CH}}_2\mathrm{Cl} \\ \mathrm{Ethene}\mathrm{Chlorine}1,2-\mathrm{Dichloroethane} \end{gathered}$$