Question

A hydrocarbon has three carbon atoms. Write down its molecular formula as an alkene.

Answer 1

Solution:

1. Alkenes

• Alkene is a hydrocarbon having a double bond between two carbon atoms.
• Its general formula is ${\mathrm{C}}_{\mathrm{n}}{\mathrm{H}}_{2\mathrm{n}}$, where ‘n’ is the number of carbon atoms.
• For example: ethene, propene, butene, and so on having a number of carbon atoms are written as ${\mathrm{C}}_2{\mathrm{H}}_4$ , ${\mathrm{C}}_3{\mathrm{H}}_6$, ${\mathrm{C}}_4{\mathrm{H}}_8$ so on respectively.

2. Determine the molecular formula of hydrocarbon as an alkene that has three carbon atoms:

Since hydrocarbon has three carbon atoms, thus, on substituting the value of$‘\mathrm{n}’$as $3$ in the general formula o alkene, we get the formula of the compound that contains three C atoms as ${\mathrm{C}}_3{\mathrm{H}}_{2\times 3}={\mathrm{C}}_3{\mathrm{H}}_6$

Thus, the molecular formula of alkene hydrocarbon that has three carbon atoms is ${\mathrm{C}}_3{\mathrm{H}}_6$.