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 8 of 55
- A. A: Thermal
- B. B: Catalytic
- C. C: Steam
- D. D: Radiations
Explanation: The correct answer is Catalytic cracking, which is a preferred method for producing higher quality gasoline.
Correct answer: B: Catalytic- A. Two hydrogen atoms
- B. Three hydrogen atoms
- C. One hydrogen atom
- D. No hydrogen atom
Explanation: The central (tertiary) carbon atom in t-butyl alcohol is bonded to three methyl groups (-CH3) and a hydroxyl group (-OH).
Correct answer: No hydrogen atom- A. 2,2-Dimethyl pentane
- B. 2,3-Dimethyl pentane
- C. 2,2-Dimethyl propane
- D. 2,2-Dimethyl butane
Explanation: 2,2-Dimethyl butane is called neohexane not neopentane.
Correct answer: 2,2-Dimethyl propane- A. 2-Ethyl-3-methyl pentane
- B. 3-Ethyl-2-methyl pentane
- C. 3-Methyl cyclohexane
- D. 3-Ethyl-4-methyl pentane
Explanation: According to IUPAC nomenclature Number the longest chain, beginning with the end nearest a branch.
Correct answer: 3-Ethyl-2-methyl pentane- A. 7
- B. 6
- C. 5
- D. 4
Explanation: Hexane (C6H14) is an alkane with six carbon atoms. Alkanes are hydrocarbons with only single bonds between carbon atoms.
Correct answer: 5- A. 3-Ethyl-2-methyl pentane.
- B. 2,3-Dimethylpentane.
- C. 2,2,4-Trimethylhexane.
- D. 2,3,4-Trimethylhexane
Explanation: The correct name of the compound 3,5,5-trimethylhexane indicates that there are three methyl groups at positions 3, 5, and 5 on the hexane…
Correct answer: 2,2,4-Trimethylhexane.- A. Decrease boiling point
- B. Prevent overheating
- C. Prevent fuel from freezing
- D. Prevent knocking
Explanation: Tetraethyllead was historically used as an anti-knock agent in gasoline.
Correct answer: Prevent knocking- A. Cracking
- B. Reforming
- C. Decomposition
- D. Isomerisation
Explanation: Option A) Cracking involves breaking down large hydrocarbons into smaller ones and does not necessarily result in a higher octane…
Correct answer: Reforming- A. Ethane
- B. Propane
- C. Butene
- D. Isobutane
Explanation: When n-butane is heated in the presence of AlCl3/HCl, it undergoes a rearrangement reaction to form Isobutane.Option A (Ethane), Option B…
Correct answer: Isobutane- A. 3-ethyl-2,2,4-trimethylpentane
- B. 4-ethyl-2,2,4-trimethylpentane
- C. 5-ethyl-2,2,4-trimethylpentane
- D. 2-ethyl-2,2,4-trimethylpentane
- E. 1-ethyl-2,2,4-trimethylpentane
Explanation: The IUPAC name for the given compound (CH3)2-CH-CH(C2H5)-C(CH3)3 is "3-ethyl-2,2,4-trimethylpentane." Here's how the name is derived:1.
Correct answer: 3-ethyl-2,2,4-trimethylpentane- A. CnH2n+1
- B. CnH2n
- C. CnH2n-1
- D. CnH2n+2
Explanation: The correct answer is Option D: CnH2n+2. This formula is the general formula for alkanes, where 'n' represents the number of carbon atoms…
Correct answer: CnH2n+2- A. 2 Butene
- B. 3,4-Dimethyl-3-hexene.
- C. 3-methyl-3-hexene
- D. 2 - Hexene.
Explanation: The ozonolysis of 3,4-dimethyl-3-hexene involves breaking the carbon-carbon double bond, resulting in the formation of carbonyl compounds.
Correct answer: 3,4-Dimethyl-3-hexene.- A. 2-Butene
- B. 2-Methyl-2-Butene
- C. 2-Pentene
- D. 2-Methyl-2-Pentene
Explanation: The ozonolysis of 2-methyl-2-butene (also known as tert-butyl ethylene) proceeds as follows: The double bond in 2-methyl-2-butene reacts…
Correct answer: 2-Methyl-2-Butene- A. Acetaldehyde
- B. Acetone
- C. Formaldehyde
- D. Benzaldehyde
Explanation: Acetone is formed in the ozonolysis of 3-dimethyl-2-butene. The double bond in the alkene is cleaved, and the resulting carbonyl groups…
Correct answer: Acetone- A. C3H6 + Br2
- B. C2H4 + HCl
- C. C3H8 + Br2
- D. C3H6 + HBr
Explanation: Markovnikov's rule states that for a hydrogen halide being added to an asymmetric alkene, the hydrogen attaches itself to the carbon…
Correct answer: C3H6 + HBr- A. 1.20Å
- B. 1.34Å
- C. 1.54Å
- D. 1.68Å
Explanation: The bond length of the Carbon-Carbon double bond, as observed in ethene is 1.34Å.
Correct answer: 1.34Å- A. Alkanes
- B. Alkenes
- C. Alkynes
- D. Benzene
Explanation: Alkenes are the most reactive of all options in terms of electrophilic addition reactions because the presence of the double bond allows…
Correct answer: Alkenes158. Baeyer's reagent is
- A. dil.alkaline KMnO4 soln.
- B. HCl+ZnCl2
- C. New in CCl4
- D. All of these
Explanation: Baeyer's reagent is a dilute alkaline potassium permanganate solution, which is commonly used to test for the presence of unsaturation in…
Correct answer: dil.alkaline KMnO4 soln.- A. 1 - pentene
- B. 2 - methyl propene
- C. 2 - butene
- D. 2,3 - dimethyl - 2 - butene
Explanation: You're looking for an alkene that, when cleaved by ozonolysis, produces only one type of aldehyde.
Correct answer: 2 - butene- A. Acetaldehyde
- B. Propanal
- C. 2-Butanol
- D. Butanone
Explanation: The acid hydrolysis of an alkyne, such as CH3-C≡C-CH3, in the presence of a mercury(II) sulfate (HgSO4) catalyst proceeds through a…
Correct answer: Butanone