A hydrocarbon molecule has 3 carbon atoms . Write down its molecular formula if it is an : (i) alkane , (ii) alkene, (iii) alkyne.

Explanation

The number of carbon atoms in the molecule of this hydrocarbon is 3, that is, n = 3.
(i) The general formula of an alkane is `C_(n)H_(2n+2)` where, n is the number of carbon atoms in one molecule of an alkane. Here, n = 3. So, if we put n = 3 in this general formula, we get `C_(3)H_(2xx3+2)` or `C_(3)H_(8)`. Thus, the molecular formula of the given hydrocarbon, if it is an alkane, is `C_(3)H_(8)`. General formula of alkene `C_(n)H_(2n)=` if `n=3`
`rArr C_(3)H_(2xx3) rArr C_(3)H_(6)`
General fromula of alkyne `C_(n)H_(2n-2) rArr ` if `n=3`
`C_(3)H_(2xx3-2) rArr C_(3)H_(4)`