Question

Observe the molecular formulae and classify the following hydrocarbons into alkanes, alkenes and alkynes. (i) \(\mathrm{C}_{2} \mathrm{H}_{4}\) (ii) \(\mathrm{C}_{2} \mathrm{H}_{6}\) (iii) \(\mathrm{C}_{4} \mathrm{H}_{10}\) (iv) \(\mathrm{CH}_{4}\) (v) \(\mathrm{C}_{3} \mathrm{H}_{6}\) (vi) \(\mathrm{C}_{3} \mathrm{H}_{8}\)

Short answer

Question: Classify the given hydrocarbons into alkanes, alkenes, and alkynes: (i) \(\mathrm{C}_2\mathrm{H}_4\), (ii) \(\mathrm{C}_2\mathrm{H}_6\), (iii) \(\mathrm{C}_4\mathrm{H}_{10}\), (iv) \(\mathrm{CH}_{4}\), (v) \(\mathrm{C}_3\mathrm{H}_6\), and (vi) \(\mathrm{C}_3\mathrm{H}_8\). Answer: After analysis and following the step-by-step classification, the hydrocarbons are classified as follows: (i) Alkene, (ii) Alkane, (iii) Alkane, (iv) Alkane, (v) Alkene, and (vi) Alkane.

Step-by-step solution

Classify Hydrocarbon (i) \(\mathrm{C}_2\mathrm{H}_4\)

Check whether the given molecular formula fits the general molecular formula of each category. -Could be an alkene (\(\mathrm{C}_2\mathrm{H}_4 = \mathrm{C}_n\mathrm{H}_{2n}\) where \(n=2\)) So, hydrocarbon (i) belongs to the alkene category.

Classify Hydrocarbon (ii) \(\mathrm{C}_2\mathrm{H}_6\)

-Could be an alkane (\(\mathrm{C}_2\mathrm{H}_6 = \mathrm{C}_n\mathrm{H}_{2n+2}\) where \(n=2\)) So, hydrocarbon (ii) belongs to the alkane category.

Classify Hydrocarbon (iii) \(\mathrm{C}_4\mathrm{H}_{10}\)

-Could be an alkane (\(\mathrm{C}_4\mathrm{H}_{10} = \mathrm{C}_n\mathrm{H}_{2n+2}\) where \(n=4\)) So, hydrocarbon (iii) belongs to the alkane category.

Classify Hydrocarbon (iv) \(\mathrm{CH}_{4}\)

-Conversion to general formula: \(\mathrm{CH}_{4} \rightarrow \mathrm{C}_1\mathrm{H}_{4}\) -Could be an alkane (\(\mathrm{C}_1\mathrm{H}_4 = \mathrm{C}_n\mathrm{H}_{2n+2}\) where \(n=1\)) So, hydrocarbon (iv) belongs to the alkane category.

Classify Hydrocarbon (v) \(\mathrm{C}_3\mathrm{H}_6\)

- Could be an alkene (\(\mathrm{C}_3\mathrm{H}_6 = \mathrm{C}_n\mathrm{H}_{2n}\) where \(n=3\)) So, hydrocarbon (v) belongs to the alkene category.

Classify Hydrocarbon (vi) \(\mathrm{C}_3\mathrm{H}_8\)

-Could be an alkane (\(\mathrm{C}_3\mathrm{H}_8 = \mathrm{C}_n\mathrm{H}_{2n+2}\) where \(n=3\)) So, hydrocarbon (vi) belongs to the alkane category. In summary, we have classified the given hydrocarbons as follows: (i) Alkene (ii) Alkane (iii) Alkane (iv) Alkane (v) Alkene (vi) Alkane