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 11 of 55
- A. AlCl3
- B. HNO3
- C. BeCl2
- D. NaCl
Explanation: Aluminium trichloride (AlCl3) is often used as a catalyst in Friedel-Crafts reactions since it acts as a Lewis acid and coordinates with…
Correct answer: AlCl3- A. Substitution reactions
- B. Addition reactions
- C. Oxidation reactions
- D. Elimination reactions
Explanation: Due to presence of pi-bonds benzene can not under go elimination reaction.
Correct answer: Elimination reactions- A. Toluene
- B. Benzene
- C. Nitrobenzene
- D. Chlorobenzene
Explanation: A process for the sulphonation of toluene in the liquid phase to produce a product comprising chiefly p-toluene sulphonic acid which…
Correct answer: Toluene- A. Benzene
- B. Ethene
- C. Ethane
- D. Ethyne
Explanation: The π bond in ethene is weak compared to the sigma bond between the two carbons.
Correct answer: Ethene- A. They have high percentage of hydrogen
- B. They have a ring structure
- C. They have high percentage of carbon
- D. They resist reaction with air
Explanation: The aromatic compound displays aromaticity. They burn with a strong sooty yellow flame.
Correct answer: They have high percentage of carbon- A. Isomerization
- B. Aromatization
- C. Dealkylation
- D. Rearrangement
Explanation: Aromatization is a chemical reaction in which an aromatic system is formed from a single nonaromatic precursor.
Correct answer: Aromatization- A. -NH2
- B. -OCH3
- C. -SO3H
- D. -OH
Explanation: -SO3H is correct because the sulfonic acid group is meta-directing in electrophilic substitution reactions of monosubstituted benzene due…
Correct answer: -SO3H- A. Toluene
- B. Xylene
- C. Benzoic acid.
- D. Acetophenone
Explanation: The introduction of an alkyl group in the benzene ring in the presence of an alkyl halide and a catalyst AICI3 is called Friedel-Crafts…
Correct answer: Benzoic acid.- A. They are resistant to react with oxygen
- B. They have a cyclic structure
- C. They have a high percentage of Carbon
- D. They have a high percentage of hydrogen
Explanation: Aromatic compound burn with sooty flame because they have a ring structure of carbon atom.
Correct answer: They have a high percentage of Carbon- A. Pyridine
- B. Payroll
- C. Furan
- D. Piperidine
Explanation: Piperidine is an organic compound with the molecular formula (CH2)5NH. This heterocyclic amine consists of a six-membered ring containing…
Correct answer: Piperidine- A. NO2
- B. COOH
- C. NH2
- D. COR
Explanation: This is correct because -NH₂ is an electron-donating group due to its +M (resonance) effect.
Correct answer: NH2- A. 1
- B. 2
- C. 3
- D. 4
Explanation: Anthracene is a polycyclic aromatic hydrocarbon consisting of three benzene rings fused together in a linear arrangement.
Correct answer: 3213. What is required other than anhydrous AICI3 when toluene is prepared by Friedal craft reaction?
- A. C6H6
- B. C6H6+ CH3Cl
- C. C6H5C2H5
- D. C6H5Cl and CH3Cl
Explanation: In the Friedel-Crafts reaction for toluene synthesis, anhydrous AlCl3 acts as a catalyst and requires the presence of benzene and CH3Cl.
Correct answer: C6H6+ CH3Cl- A. Aldehyde
- B. Acetophenone
- C. Benzyl Chloride
- D. Benzophenone
Explanation: The reaction of benzene with acetyl chloride(CH3COCl) in the presence of a catalyst like aluminum chloride (AlCl₃) is known as the…
Correct answer: Acetophenone- A. II, III and IV
- B. II and III
- C. I and IV
- D. I, II and IV
Explanation: -CHO and -COOH are meta (3,5) directing groups as they are electron withdrawing groups in nature.
Correct answer: II and III- A. Cl+
- B. Cl-
- C. Cl
- D. FeCl3
Explanation: In the chlorination of benzene, the electrophile is the chloronium ion (Cl+), which is formed in the presence of a Lewis acid like FeCl3.
Correct answer: Cl+- A. Deactivating
- B. Neutral
- C. Activating
- D. All of these
Explanation: Activating groups are most likely to be ortho, para directing as they donate electrons to the benzene ring, increasing its reactivity.
Correct answer: Activating- A. Alkylation
- B. Acylation
- C. Halogenation
- D. Nitration
Explanation: Benzene can be converted to acetophenone (methyl phenyl ketone) by Friedel-Crafts acylation.
Correct answer: Acylation- A. Polymerization
- B. Elimination
- C. Addition
- D. Substitution
Explanation: The alkanes or paraffins (Latin: parum = little, affins = affinity) under ordinary condition are inert towards acids, alkalis, oxidizing…
Correct answer: Substitution- A. Ethene
- B. Acetylene
- C. Heptane
- D. Ethane
Explanation: In the formation of a p-bond, the partially filled p-orbitals overlap in a parallel fashion.
Correct answer: Ethene