Hydrocarbons are the simplest and most fundamental organic compounds, consisting entirely of carbon and hydrogen. From the gasoline that powers our vehicles to the plastic materials we use daily, hydrocarbons are everywhere. As NEET aspirants, understanding hydrocarbons can give you a foundational base to tackle more complex organic chemistry topics. Let’s embark on this journey with 20 engaging MCQs on hydrocarbons.
1. Which of the following is an example of an alkane?
Answer:
Explanation:
Alkanes are saturated hydrocarbons with the general formula CnH2n+2. Butane (C4H10) fits this criterion.
2. What type of hybridization is exhibited by ethyne?
Answer:
Explanation:
Ethyne (acetylene) has a triple bond which indicates sp hybridization in its carbon atoms.
3. Which hydrocarbon undergoes addition reactions?
Answer:
Explanation:
Ethene is an alkene and has a double bond, making it capable of undergoing addition reactions.
4. Toluene is derived from:
Answer:
Explanation:
Toluene is benzene with a methyl group attached.
5. Which of the following is not an aromatic hydrocarbon?
Answer:
Explanation:
Propyne is an alkyne, whereas the other options are aromatic hydrocarbons.
6. Alkenes generally have the formula:
Answer:
Explanation:
Alkenes are unsaturated hydrocarbons with a double bond, having the general formula CnH2n.
7. Which of the following reactions will methane readily undergo?
Answer:
Explanation:
Methane, being an alkane, will predominantly undergo substitution reactions.
8. The presence of which functional group differentiates aldehydes from ketones?
Answer:
Explanation:
Aldehydes have a -CHO functional group, while ketones have a C=O bond within the carbon chain.
9. Which of the following hydrocarbons has a ring structure?
Answer:
Explanation:
Cyclohexane has a 6-membered ring structure.
10. Freidel-Crafts alkylation is used for:
Answer:
Explanation:
Freidel-Crafts alkylation is used for introducing an alkyl group to an aromatic ring, such as benzene.
11. Combustion of hydrocarbons generally produces:
Answer:
Explanation:
Complete combustion of hydrocarbons in the presence of oxygen yields carbon dioxide and water.
12. Which of the following is a secondary alkyl halide?
Answer:
Explanation:
A secondary alkyl halide has the halogen atom attached to a secondary carbon. In this case, (CH3)2CH-Br is the correct option.
13. Pyrolysis of hydrocarbons involves:
Answer:
Explanation:
Pyrolysis is the thermal decomposition of hydrocarbons in the absence of oxygen.