Free Chemistry of Hydrocarbons MCQs with Answers
1,091 Chemistry of Hydrocarbons MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Hydrocarbons are studied through the structures and reactions of alkanes, alkenes, alkynes and aromatic compounds. Coverage includes free radical substitution in alkanes, electrophilic addition to carbon-carbon multiple bonds, benzene substitution, aromatic stability and the difference between addition reactions of alkenes and substitution reactions of benzene.
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Read the Chemistry of Hydrocarbons notesFree MDCAT chapter notes with key terms1,091 questions · page 22 of 55
- A. 3-Methyl-1-penten-4-yne
- B. 3-Methyl-4-penten-1-yne
- C. 2-Methyl-1-penten-3-yne
- D. 3-Methyl-3-penten-1-yne
Explanation: The correct IUPAC name for the compound is 3-Methyl-1-penten-4-yne. The hydrocarbon chain is numbered to provide the lowest possible…
Correct answer: 3-Methyl-1-penten-4-yne- A. Potassium formate
- B. Potassium acetate
- C. Potassium succinate
- D. Potassium fumarate
Explanation: Ethane is obtained by electrolyzing potassium acetate in Kolbe's electrolysis.
Correct answer: Potassium acetate- A. Cracking
- B. Hydrolysis
- C. Oxidation
- D. Distillation
Explanation: The correct answer is Cracking. This process specifically targets converting liquid hydrocarbons into gaseous ones by breaking down larger…
Correct answer: Cracking- A. m-Bromophenol
- B. o-and p-Bromophenol
- C. 2,4-Dibromophenol
- D. 2,4,6-Tribromophenol
Explanation: When phenol is treated with excess of bromine water, it gives 2,4,6-tribromophenol as the major product.
Correct answer: 2,4,6-Tribromophenol- A. Tetrahedral
- B. Hexagonal planar
- C. Hexagonal irregular
- D. Trigonal planar
Explanation: The correct structure of benzene is a planar ring of six carbon atoms with delocalized electrons.
Correct answer: Hexagonal planar- A. Hydrochloric acid
- B. Oxalic acid
- C. Acetic acid
- D. Formic acid
Explanation: When ethyne is oxidized with strong alkaline potassium permanganate (KMnO4), it forms oxalic acid.
Correct answer: Oxalic acid- A. Make it reactive
- B. Makes ortho position of benzene more reactive than others
- C. Makes Meta position of benzene more reactive than others
- D. Makes para position of benzene more reactive than others
Explanation: The correct answer is Option C: Makes Meta position of benzene more reactive than others.
Correct answer: Makes Meta position of benzene more reactive than others- A. Hydrogen
- B. Both carbon and hydrogen
- C. Carbon
- D. Oxygen
Explanation: The correct answer is 'Both carbon and hydrogen'. Hydrocarbons are organic compounds that specifically consist of carbon and hydrogen…
Correct answer: Both carbon and hydrogen- A. Primary alcohol
- B. Secondary alcohol
- C. Tertiary alcohol
- D. All of above
Explanation: Primary alcohols, with their linear structure and terminal -OH group, exhibit the highest boiling points due to strong intermolecular…
Correct answer: Primary alcohol- A. Neither electrophilic nor nucleophilic addition
- B. Nucleophilic addition only
- C. Electrophilic only
- D. Both electrophilic and nucleophilic addition
Explanation: Alkynes are capable of undergoing both electrophilic addition and nucleophilic addition reactions.
Correct answer: Both electrophilic and nucleophilic addition- A. 109.5°
- B. 180°
- C. 90o
- D. 120o
Explanation: In sp2 hybridization, the orbital orientation is trigonal planar. This means that the three hybridized orbitals are arranged in a plane at…
Correct answer: 120o- A. Decomposition
- B. Halogenation
- C. Sulphonation
- D. Nitration
Explanation: Picric acid is formed from phenols through a process called nitration, where a nitro group is introduced into the molecule.
Correct answer: Nitration- A. 154.0 pm
- B. 120.0 pm
- C. 134.0 pm
- D. 139.7 pm
Explanation: The correct answer is 139.7 pm. The typical C-C bond length in benzene is around 140 pm.
Correct answer: 139.7 pm- A. Sigma bond
- B. Two pi bond
- C. One pi bond
- D. Due to electrophilic nature
Explanation: The reactivity of an alkene is primarily due to the presence of a pi bond.
Correct answer: One pi bond- A. Alkyne
- B. Alkene
- C. Alkane
- D. All of these
Explanation: When ethylene bromide is treated with zinc (Zn), it undergoes dehydrohalogenation, resulting in the formation of an alkene, specifically…
Correct answer: Alkene- A. White precipitate
- B. Pink precipitate
- C. Blue precipitate
- D. Black precipitate
Explanation: When bromine water reacts with phenol, it forms a white precipitate known as 2,4,6-tribromophenol.
Correct answer: White precipitate- A. Methanol
- B. Methane
- C. Formaldehyde
- D. Formic acid
Explanation: The correct answer is methane. It is the simplest member of organic compounds, composed of a single carbon atom bonded to four hydrogen…
Correct answer: Methane- A. Alkanes and alkenes can be distinguished by Br2/CCl4 in halogenation.
- B. Alkanes and alkynes can be distinguished by specific reagents like Tollens' test.
- C. Alkanes and alkynes can be distinguished by Br2/CCl4 in Baeyer's test.
- D. Alkyne-1 and alkyne-2 can be distinguished by specific reagents like Cu2Cl2/NH4OH.
Explanation: The correct answer is Option C, which incorrectly states that alkanes and alkynes can be distinguished by Br2/CCl4 in Baeyer's test.
Correct answer: Alkanes and alkynes can be distinguished by Br2/CCl4 in Baeyer's test.- A. Deformation
- B. Rearrangement
- C. Reformation
- D. Aromatization
Explanation: The correct answer is Option D: Aromatization. This term specifically refers to the process of converting n-hexane to benzene by heating.
Correct answer: Aromatization- A. Addition reactions
- B. Elimination reactions
- C. Reduction reactions
- D. Substitution reactions
Explanation: Alkanes predominantly undergo substitution reactions where hydrogen atoms are replaced by other atoms or groups.
Correct answer: Substitution reactions