Question

Which of the following hydrocarbons is unsaturated?
C₃H₄; C₂H₆

Answer 1

C₃H₄ (C_nH_2n-2) is an unsaturated hydrocarbon. It has three carbon atoms, of which two carbon atoms are connected by a triple bond. Here, n is 3. Now, substituting n in the formula of the alkynes, we get, ${\mathrm{C}}_3{\mathrm{H}}_{2\times 3-2}={\mathrm{C}}_3{\mathrm{H}}_4$. This compound is called propyne. C₂H₆ is a saturated hydrocarbon with two carbon atoms bonded by a single bond.