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 22 of 23
- A. 1-Chloro-2-methylpropane
- B. 1-Chloro-2-methylbutane
- C. Isobutyl chloride
- D. 2-Methyl-3-chloropropane
Explanation: There are 3 carbons in a chain, Cl group is bonded to the 1st carbon and methyl is bonded to the 2nd carbon.
Correct answer: 1-Chloro-2-methylpropane- A. 4-methyl-6-chloro heptane
- B. 2-chloro-4-methyl heptane
- C. 2-chloro-4-n propyl hexane
- D. 2-chloro-4-n propyl pentane
Explanation: The longest carbon chain is 7 carbons long and has only single carbon-carbon bonds hence heptane.The numbering would favour chloro group…
Correct answer: 2-chloro-4-methyl heptane- A. Cl-CH2-CH2-Cl
- B. Cl-CH2-CH2-Br
- C. CF3-CHCl-Br
- D. Br-CH2-CH2-Br
Explanation: The following is the structure of halothane.
Correct answer: CF3-CHCl-Br- A. Primary alkyl halides
- B. Secondary alkyl halides
- C. Tertiary alkyl halides
- D. Quaternary alkyl halides
Explanation: Non-pentyl chloride is the primary alkyl halide because in it, Chlorine atom is linked to a primary carbon atom.
Correct answer: Primary alkyl halides- A. Cl, Br, I, F
- B. F, CI, Br, I
- C. Br, I, F, CI
- D. I, F, Cl, Br
Explanation: The correct reactivity order of alkyl halides is R-F < R-Cl < R-Br < R-I because the C-F bond is the strongest (making fluorine the least…
Correct answer: F, CI, Br, I- A. n-butane
- B. Propane
- C. Iso-butane
- D. Alcohol
Explanation: Explanation:Alkanes are produced when grignard reacts with:Water Ammonia AlcoholAs a result, n-butane will be produced in the above…
Correct answer: n-butane- A. Gets inverted
- B. Remains same
- C. Depends upon the carbon atom
- D. Depends upon the electronegativity of halide
Explanation: A is correct as during SN2 reaction, alkyl halide molecule gets inverted.B is incorrect as during SN2 reaction, alkyl halide doesnt stay…
Correct answer: Gets inverted- A. H2O at room temperature
- B. Ethanol, heat
- C. KOH in alcohol
- D. Dilute NaOH(aq) warm
Explanation: The given reaction is an example of alkaline hydrolysis or nucleophilic substitution reaction in which a halogen atom in an alkyl halide…
Correct answer: Dilute NaOH(aq) warm- A. NO2
- B. NH3
- C. NO2+
- D. NH4+
Explanation: A nucleophile is electron-rich species and donates electron pairs to electron-deficient species. Therefore, ammonia (NH3) is a nucleophile.
Correct answer: NH3- A. Breakage of covalent bond
- B. Formation of carbocation
- C. Transition state
- D. Attack of nucleophile
Explanation: The nucleophile has a negative / partially negative charge and it readily attacks the carbocation in SN1 reactions (which has a positive…
Correct answer: Attack of nucleophile- A. Nucleophiles
- B. Cations
- C. Free radicals
- D. Anions
Explanation: A nucleophile is a chemical species that donates an electron pair to form a chemical bond in relation to a reaction.
Correct answer: Nucleophiles- A. Primary carbocation
- B. Secondary carbocation
- C. Tertiary carbocation
- D. Methyl carbocation
Explanation: Methyl Carbocation (CH₃⁺)Structure: Only has one carbon atom, with no alkyl groups to stabilize the positive charge.Stability: Least…
Correct answer: Methyl carbocation- A. Primary>secondary>tertiary
- B. Tertiary>secondary>primary
- C. Secondary>primary>tertiary
- D. Primary>tertiary >secondary
Explanation: Tertiary > Secondary > Primary (Correct)Explanation: Tertiary carbocations are the most stable due to inductive and hyperconjugation…
Correct answer: Tertiary>secondary>primary- A. SN1
- B. SN2
- C. E1
- D. E2
Explanation: In organic chemistry, the reaction involving the simultaneous breaking of a carbon-halogen bond (-C-X) and the formation of a…
Correct answer: SN2- A. Alcoholic KOH
- B. Aqueous KOH
- C. Aqueous NaOH
- D. Alcoholic HaOH
Explanation: The suitable reagent used for dehydrohalogenation of alkyl halides would be alcoholic KOH. Here are some examples.
Correct answer: Alcoholic KOH- A. 2-Methyl propane
- B. 2-Methyl propene
- C. 2-Methyl-1 propanol
- D. 2-pentanol
Explanation: The unimolecular elimination (E1) reaction of 2-Bromo-2-methyl propane involves the removal of the bromine atom, resulting in the…
Correct answer: 2-Methyl propene- A. Nucleophilic substitution reaction
- B. Elimination reaction
- C. Nucleophilic addition
- D. None of the above
Explanation: It should be noted that whenever the reagent is alcoholic / ethanolic KOH or NaOH, the reaction that follows is elimination
Correct answer: Elimination reaction- A. Zn dust
- B. Conc. H2SO4
- C. Alcoholic KOH
- D. Aqueous KOH.
Explanation: Dehydrohalogenation of an alkyl halide is carried out in the presence of alcoholic KOH (potassium hydroxide dissolved in alcohol).
Correct answer: Alcoholic KOH- A. Substrate reaction
- B. Elimination reaction
- C. Oxidation reaction
- D. Free radical reaction
Explanation: A greater number of alkyl groups on a substrate favors elimination reactions because it leads to the formation of more stable and…
Correct answer: Elimination reaction- A. Alkyl Halide and Mg
- B. Alkane and Mg
- C. Alcohol and Mg
- D. None of them
Explanation: Alkyl Halide and Mg extremely good nucleophiles, reacting with electrophiles such as carbonyl compounds and epoxides
Correct answer: Alkyl Halide and Mg