Question

Write IUPAC names of the compounds of alkane, alkene and alkyne, containing 3 carbons.

Answer 1

$\bullet$ Alkane containing 3 carbon atoms:
With n=3, the molecular formula of an alkane is ${\text{C}}_3{\text{H}}_8$.
The condensed structural formula is ${\text{CH}}_3{\text{CH}}_2{\text{CH}}_3$.
Therefore, the IUPAC name is propane.
$\bullet$ Alkene containing 3 carbon atoms:
With n=3, the molecular formula of an alkene is ${\text{C}}_3{\text{H}}_6$.
The condensed structural formula is ${\text{CH}}_3\text{CH}={\text{CH}}_2$.
Therefore, the IUPAC name is propene or prop-1-ene.
$\bullet$ Alkyne containing 3 carbon atoms:
With n=3, the molecular formula of an alkyne is ${\text{C}}_3{\text{H}}_4$.
The condensed structural formula is ${\text{CH}}_3\text{C}\equiv \text{CH}$.
Therefore, the IUPAC name is propyne or prop-1-yne.