Question

Alkynes are unsaturated hydrocarbons. Justify this statement giving two reasons.

Answer 1

Step 1:

Alkynes are unsaturated hydrocarbons that has Carbon $\left(\mathrm{C}\right)$, Hydrogen $\left(\mathrm{H}\right)$ atoms connected through bonds.

Alkynes have Carbon-Carbon $(\mathrm{C}\equiv \mathrm{C})$ atoms connected through triple and single bond, Carbon-Hydrogen $(\mathrm{C}-\mathrm{H})$ atoms that are only connected through single bonds.

Example of Alkyne is Ethyne $\left({\mathrm{C}}_2{\mathrm{H}}_2\right)$

Step 2:

Two reason to justify that Alkynes are unsaturated hydrocarbons are as follows:

• Alkynes contain Carbon-Carbon triple bond. Example is Ethyne $(\mathrm{H}-\mathrm{C}\equiv \mathrm{C}-\mathrm{H})$.
• Ethyne $\left({\mathrm{C}}_2{\mathrm{H}}_2\right)$ is an unsaturated hydrocarbon because this molecule has four Hydrogen atoms less than the saturated hydrocarbon that is Ethane $\left({\mathrm{C}}_2{\mathrm{H}}_6\right)$