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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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Nomenclature, Structure and ReactivityNucleophilic SubstitutionElimination Reactions
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458 questions · page 17 of 23

321. CCI4 has all of the following characteristic features EXCEPT:

  • A. It is colourless liquid
  • B. It is used as industrial solvent
  • C. It is insoluble in water and soluble in alcohol for fat, oil etc
  • D. It is inflammable

Explanation: CCl4 is not flammable because the carbon-chlorine bonds are very strong.

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Correct answer: It is inflammable

322. Consider the following reaction of Grignard reagent with methanal (a carbonyl compound) followed by hydrolysis:

  • A. Electrophilic addition reaction
  • B. β-elimination
  • C. Nucleophilic addition reaction
  • D. Nucleophilic substitution reaction

Explanation: The reaction of a Grignard reagent with methanal (formaldehyde) followed by hydrolysis is a nucleophilic addition reaction.

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Correct answer: Nucleophilic addition reaction

323. Which of the following type of alkyl halide is the most reactive w.r.t SN1:

  • A. R - X
  • B. Option B
  • C. R - CH2 - X
  • D. Option D

Explanation: Tertiary alkyl halides are the most reactive in SN1 reactions because they have the most stable carbocation intermediates.

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Correct answer: Option B

324. Alkyl halides are considered to be very reactive compounds towards nucleophiles because:

  • A. They have an electrophilic carbon
  • B. They have an electrophilic carbon and a good leaving group
  • C. They have an electrophilic carbon and bad leaving groups
  • D. They have a nucleophilic carbon and a good leaving groups

Explanation: Alkyl halides are considered to be very reactive compounds towards nucleophiles because they have an electrophilic carbon and a good…

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Correct answer: They have an electrophilic carbon and a good leaving group

325. Which one of the followings is halothane?

  • A. Option A
  • B. Option B
  • C. Option C
  • D. Option D

Explanation: The chemical formula of halothane is C2H3BrClF3. It is a trihalogenated methane, which means that it has three halogen atoms (bromine…

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Correct answer: Option B

326. Identify the incorrect statement about the use of chloroform:

  • A. It is used as an anesthetic substance
  • B. It is used as a solvent for fats waxes and resins
  • C. It is used in manufacturing freons
  • D. It is used as preservative for anatomical specimen

Explanation: Chloroform is not used in manufacturing freons. Therefore, option c is correct.

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Correct answer: It is used in manufacturing freons

327. All of the following are characteristic features of Teflon plastic EXCEPT:

  • A. It is valuable plastic which resists the action of acid and alkali
  • B. It is used as coating the electrical wiring
  • C. It is used as a non-stick coating for cooking pans
  • D. It reacts with oxidants

Explanation: The correct answer to the question "All of the following are characteristic features of Teflon plastic EXCEPT:" is option D: It acts with…

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Correct answer: It reacts with oxidants

328. Which of the following is the most dangerous factor which damages ozone?

  • A. Aerosol spray
  • B. Use of chlorofluorocarbons
  • C. Effect of SO2 and NO2 Pollutant
  • D. Global warming by CO2

Explanation: Chlorofluorocarbons breaks ozone molecules by releasing chlorine free radicals.

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Correct answer: Use of chlorofluorocarbons

329. In which of the following reactions alcohol is produced?

  • A. Reaction of alkyl halide with aqueous KOH
  • B. Reaction of alkyl halide with alcoholic KOH
  • C. Reaction of alkyl halide with KCN followed by acidic hydrolysis
  • D. Reactions of alkyl halide with sodium alkoxide

Explanation: The correct option for the production of alcohol is B. In the reaction of alkyl halide with alcoholic KOH (option B), an elimination…

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Correct answer: Reaction of alkyl halide with alcoholic KOH

330. Consider the following structure of alkyl halide: Which of the following correct name of given structure according to IUPAC system is:

  • A. 1-Bromo-2-methylbutane
  • B. 4-Bromo-3-methylbutane
  • C. 4-Bromo-2-methylbutane
  • D. 1-Bromo-3-mehtylbutane

Explanation: When applying IUPAC rules:1. Longest continuous carbon chain: There is a four-carbon chain (butane).2.

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Correct answer: 1-Bromo-2-methylbutane

331. Which of the following is correct statement about substrate and leaving group?

  • A. The molecule which undergoes nucleophilic substitution reaction is called substrate
  • B. The group or species which leaves the substrate is called leaving group (nucleofuge)
  • C. Both A and B
  • D. Neither A nor B

Explanation: C is correct because both statements A and B are accurate descriptions in the context of nucleophilic substitution reactions.A.

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Correct answer: Both A and B

332. Which of the following carbocation is most stable?

  • A. (CH3)3C-CH2
  • B. (CH3)3C
  • C. CH3CH2CH2
  • D. CH3CH CH2CH3

Explanation: The most stable carbocation is the one that has the most alkyl groups attached to it.

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Correct answer: (CH3)3C

333. Which one of the following is a correct statement about the two alkenes: CH3 - CH2 - CH = CH2 and CH3 - CH = CH3?

  • A. Neither may be polymerized
  • B. Neither reacts with bromine to give 1,4-Dibromobutane
  • C. Neither reacts with hydrogen to form butane
  • D. Neither exhibits cis-trans isomerism

Explanation: Cis-trans isomerism, also known as geometric isomerism, occurs in alkenes when there is restricted rotation around the carbon-carbon…

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Correct answer: Neither exhibits cis-trans isomerism

334. In elimination reaction there is another site present in the alkyl halide molecule where the attacking reagent (base) can attack at the same time. Such a site is an electrophilic hydrogen atom (β-hydrogen is acidic in nature) which is attached to the β-carbon of the alkyl halide. When the attack takes place on hydrogen we get an alkene there are two types of elimination reactions (E1 and E2): Which of the following statements is incorrect about E2 elimination reaction?

  • A. Option A
  • B. Option B
  • C. Option C
  • D. Option D

Explanation: Order of ease of E2 elimination reaction in alkyl halides is 1° > 2° > 3°. Therefore, option c is correct.

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Correct answer: Option C

335. Consider the following statement about physical properties of alkyl halides: I. Lower alkyl halides CH3CI, C2H5Cl and CH3F are gases at room temperature. II. Alkyl halides upto C18 are colorless liquids. III. Those beyond C18 are colourless solids. IV. They are usually insoluble in water due to their inability to form hydrogen bonding with water. Which of the above statement is/are correct?

  • A. I only
  • B. lI only
  • C. Ill and IV only
  • D. I, II, III and IV

Explanation: The correct answer is: D. I, II, III, and IV Explanation: I. Lower alkyl halides like CH3Cl, C2H5Cl, and CH3F are indeed gases at room…

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Correct answer: I, II, III and IV

336. In elimination reaction there is another site present in the alkyle halide molecule where the attacking reagent (base) case attack at the same time. Such a site is an electrophilic hydrogen atom (β-hydrogen is acidic in nature) which is attached to the β-carbon of the alkyl halide. When the attack takes place on hydrogen we get an alkene there are two types of elimination reactions (E1 and E2): Which of the following statements is incorrect about E1 elimination reaction?

  • A. Option A
  • B. Option B
  • C. Option C
  • D. Option D

Explanation: Order of reactivity of alkyl halides towards elimination reaction (both E1 and E2) is 3∘>2∘>1∘. Therefore, option c is correct.

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Correct answer: Option C

337. Consider the following differences between SN1 and SN2 reactions. Which of the above statement is/are correct?

  • A. I only
  • B. II only
  • C. IIl and IV only
  • D. I, II, III and IV

Explanation: All of the given points are correct in order to differentiate between SN1 and SN2 reaction. Therefore, option d is correct.

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Correct answer: I, II, III and IV

338. Which one of the following halides is most reactive towards nucleophilic substitution reaction?

  • A. C2H5Br
  • B. C2H5F
  • C. C2H5I
  • D. C2H5Cl

Explanation: Among the options provided, C2H5I (ethyl iodide) is generally more reactive.

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Correct answer: C2H5I

339. An the electron deficient species are classified as:

  • A. Nucleophiles
  • B. Bases
  • C. Electrophiles
  • D. All of these

Explanation: Electron-deficient species are classified as electrophiles. Electrophiles are species that have a deficiency or partial positive charge of…

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Correct answer: Electrophiles

340. The carbon atom carrying positive charge and attached to three other atoms or groups is called:

  • A. Carbonium ion
  • B. Oxonium ion
  • C. Carbon ion
  • D. Carbonion

Explanation: The correct answer is A. Carbonium ion. This ion is a carbon atom carrying a positive charge and bonded to three other atoms or groups.

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Correct answer: Carbonium ion
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