Free Alkyl Halides MCQs with Answers
458 Alkyl Halides MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Alkyl halides are named and related to their carbon-halogen structure, polarity and reactivity. The key reactions are nucleophilic substitution by SN1 and SN2 mechanisms and elimination by E1 and E2 mechanisms, including how substrate structure, nucleophile, base, solvent and temperature influence substitution versus elimination.
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Read the Alkyl Halides notesFree MDCAT chapter notes with key terms458 questions · page 5 of 23
- A. Cl2
- B. Br2
- C. I2
- D. F2
Explanation: What we are seeing is an example of free radical substitution in which Cl2, in the presence of UV light, breaks into free radicals which…
Correct answer: Cl2- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: As in the bromination of para-xylene bromine cation attacks on xylene ring at the ortho position and forms the intermediate.
Correct answer: Option C- A. Primary alkyl halides
- B. Secondary alkyl halides
- C. Tertiary alkyl halides
- D. Both primary and tertiary alkyl halides
Explanation: SN2 reactions has a nucleophilic attack on an electrophilic carbon. Resulting in a less steric congestion for this attack results in a…
Correct answer: Primary alkyl halides- A. H2S
- B. BF3
- C. NH3
- D. CN-
Explanation: A nucleophile is an electron rich species and donates electron pairs to electron deficient species.
Correct answer: BF3- A. Noble gases
- B. Halogens
- C. Metals
- D. Metalloids
Explanation: Alkyl halides (RX, where R is an alkyl group and X is F, Cl, Br, or I) are classified as primary, secondary, or tertiary according to the…
Correct answer: Halogens- A. Sulphuric acid and carbon dioxide
- B. Sulphur dioxide and hydrogen chloride
- C. Sulphur chloride and hydrogen dioxide
- D. Sulphuric acid and hydrogen chloride
Explanation: Ethyl alcohol on reaction with Thionyl chloride gives ethyl chloride, Hydrogen chloride and sulphur dioxide gas.CH3CH2OH+SOCl2…
Correct answer: Sulphur dioxide and hydrogen chloride- A. C-I
- B. C-H
- C. C-CI
- D. C-F
Explanation: The correct answer is D. C-F. Fluorine (F) forms a very strong bond with carbon (C) due to its high electronegativity.
Correct answer: C-F- A. Zinc chloride
- B. Pyridine
- C. Sodium chloride
- D. Thionyl chloride
Explanation: Zinc Chloride is the correct option. Option A
Correct answer: Zinc chloride- A. Primary alkyl halide
- B. Secondary alkyl halide
- C. Tertiary alkyl halide
- D. None of the above
Explanation: 2-Chloro-2-methylpropane is a tertiary alkyl halide as the carbon the chlorine is bonded to is also bonded to three methyl groups.
Correct answer: Tertiary alkyl halide- A. R-Cl>R-Br>R-F>R-I
- B. R-I>R-Br>R-Cl>R-F
- C. R-I>R-Cl>R-Br>R-F
- D. None of these
Explanation: Reactivity of alkyl halides increases down the group as the carbon-halogen bond strength decreases down the group.
Correct answer: R-I>R-Br>R-Cl>R-F91. Which balanced chemical equation show the formation of ethanoyl chloride using thionyl chloride?
- A. HCOOH + SOCl2 → HCOCI + SO2 + HCI
- B. CH3CH2COOH + 2SOCl → CH3CH2COCl + SO2 + HCI
- C. CH3CH2COOH + 2SOCl → CH3CH2COC1 + SO3 + HCI
- D. CH3COOH + SOCl2 → CH3COCl + SO2 + HCI
Explanation: Thionyl chloride is SOCl2 and it reacts with carboxylic acids to form acyl chlorides.Options B and C do not involve thionyl chloride, it…
Correct answer: CH3COOH + SOCl2 → CH3COCl + SO2 + HCI92. Which product is obtained by the hydrolysis of 1-chlorobutane with the aqueous sodium hydroxide?
- A. 1-butanal
- B. 1-butanol
- C. 1-butene
- D. Butanone
Explanation: The scenario describes nucleophilic substitution of 1-chlorobutane, where -OH serves as the nucleophile, as sodium hydroxide is aqueous…
Correct answer: 1-butanol- A. Secondary
- B. Primary
- C. Tertiary
- D. All of these
Explanation: The SN2 reaction mechanism involves the nucleophilic substitution reaction of the leaving group (which generally consists of halide groups…
Correct answer: Primary- A. Chloropentane
- B. n-Chloropentane
- C. n-pentyl chloride
- D. 1-chloropentane
- E. n-butanyl chloride
Explanation: CH3-CH2-CH2-CH2-Cl (straight chain)The common name of the compound is n-butanyl chloride as it has a 4 carbon atom chain with a chlorine…
Correct answer: n-butanyl chloride- A. Cl-
- B. Br-
- C. I-
- D. OH-
Explanation: The weaker the base, the better the leaving group. Since OH- is the strongest base out of the options given, since the remaining options…
Correct answer: OH-- A. E1, E2
- B. E1, S2
- C. E2, S1
- D. E2, S2
Explanation: Elimination reactions compete with substitution reactions because both reaction mechanisms favor the same conditions: ''Alkyl halide and a…
Correct answer: E2, S2- A. Two
- B. One
- C. Three
- D. None of these options is correct
Explanation: If a simple benzene ring is monosubstituted (just one H replaced by one X group) then there could only be 1 compound (i.e.
Correct answer: One- A. Multi-step reaction
- B. Two-step reactions
- C. Concerted reaction
- D. Three-step reaction
Explanation: SN1 reaction mechanism follows a step-by-step process wherein first, the carbo-cation is formed from the removal of the leaving group.
Correct answer: Two-step reactions- A. Alkyl bromide
- B. Alkyl fluoride
- C. Alkyl chloride
- D. Alkyl iodide
Explanation: Option A) Alkyl bromide is less reactive towards magnesium than alkyl iodide, but more reactive than alkyl chloride and alkyl…
Correct answer: Alkyl iodide- A. Alkenes
- B. Alkanes
- C. Alkynes
- D. Alcohols
Explanation: Alkyl halides (except fluorides) on reduction with zinc dilute hydrochloric acid give alkanes:Zn +H2 → ZnH2ZnH2 + 2CH3Cl → ZnCl2 +2CH4
Correct answer: Alkanes