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 7 of 23
- A. Nucleophilic substitution
- B. Electrophilic addition
- C. Electrophilic substitution
- D. Nucleophilic addition
Explanation: When a nucleophile replaces a halide group in an alkyl halide, this type of reaction is called a nucleophilic substitution reaction.
Correct answer: Nucleophilic substitution- A. Addition
- B. Nucleophilic substitution
- C. Electrophilic substitution
- D. Electrophilic addition
Explanation: Alkyl halides give nucleophilic substitution and elimination reactions.
Correct answer: Nucleophilic substitution- A. Solid
- B. Liquid
- C. Gas
- D. All of the Above
Explanation: b) Liquid: SN2 reactions can occur in the liquid phase, but they may not be favored depending on the specific solvent used.
Correct answer: Liquid- A. Iodine reacts slowly
- B. Iodine reacts reversibly
- C. HI formed reduces alkyl iodide again starting material
- D. All of these
Explanation: All of the above reasons contribute to the factors which make it impossible to synthesis iodoalkanes by halogenation of alkanes.
Correct answer: All of these- A. Transition state
- B. Intermediate
- C. Carbocation
- D. Carbanion
Explanation: Option A: In an SN2 reaction, a transition state is formed. The transition state represents the highest energy point in the reaction…
Correct answer: Transition state- A. Alkanes
- B. Alcohols
- C. Carboxylic acids
- D. All of these
Explanation: Option A: Alkanes: Grignard reagents can be used to prepare alkanes through the reaction with alkyl halides.
Correct answer: All of these- A. SN2
- B. E2
- C. SN1
- D. None of these
Explanation: Option A: SN2 (substitution nucleophilic bimolecular) reaction: The rate of an SN2 reaction is influenced by the concentration of the…
Correct answer: SN1- A. Ca in anhydrous ether
- B. Mg in dry ether
- C. Mg in hydrous ether
- D. Ca in dry ether
Explanation: Option A: This option is incorrect. Grignard reagents are not typically prepared using calcium (Ca) metal.
Correct answer: Mg in dry ether- A. Nucleophilic unimolecular addition reactions
- B. Nucleophilic bimolecular substitution reactions
- C. Nucleophilic bimolecular addition reactions
- D. Nucleophilic unimolecular substitution reactions
Explanation: SN2 (Substitution Nucleophilic Bimolecular) reactions are a type of nucleophilic substitution reaction that occurs when a nucleophile…
Correct answer: Nucleophilic bimolecular substitution reactions- A. RMX
- B. R2MgX
- C. RMgX2
- D. RMgX
Explanation: The general formula for Grignard reagents is RMgX, where R is an organic group (such as alkyl, aryl, or vinyl) and X is a halogen…
Correct answer: RMgX- A. C-I
- B. C-H
- C. C-Cl
- D. C-F
Explanation: C-F has the highest bond energy, followed by C-H, C-Cl, and C-I. This trend can be explained by the increasing electronegativity of the…
Correct answer: C-F- A. Cl-
- B. OH
- C. OR
- D. NH2
Explanation: In a chemical reaction, a leaving group is a molecular fragment that departs from the reactant molecule, taking with it a pair of…
Correct answer: Cl-- A. SN2
- B. E1
- C. SN1
- D. E2
Explanation: If a base is added to a solution of an alkyl halide in a nonpolar solvent, an E2 elimination reaction will take place.In an E2 elimination…
Correct answer: E2- A. CH3CN
- B. CH3Cl
- C. CH3CH2NH2
- D. None of these options are correct
Explanation: OPTION A: CH3CN is not formed when NaCl reacts with CH3MgBr.OPTION B: CH3Cl is formed when NaCl reacts with CH3MgBr.
Correct answer: CH3Cl- A. From opposite side of leaving group
- B. From front of leaving group
- C. From both sides
- D. None of these
Explanation: OPTION A: It can attack from both sides either from the opposite side of leaving a group or from the front of leaving the group.OPTION B…
Correct answer: From both sides- A. Water
- B. Alcohol
- C. Anhydrous ether
- D. Carbon tetrachloride
Explanation: OPTIONS A, B: Water and alcohol would react with the Grignard reagent, leading to its destruction and preventing its formation.OPTION C…
Correct answer: Anhydrous ether- A. 2
- B. 3
- C. 4
- D. 1
Explanation: There are three types of alkyl halides: primary, secondary, and tertiary.
Correct answer: 3- A. Br+
- B. CH3+
- C. NH3
- D. CH4
Explanation: A nucleophile is a specie with a lone pair(s) and will attack an electron-deficient atom.
Correct answer: NH3- A. Retention in configuration
- B. Inversion in Configuration
- C. 50% retention and 50% inversion in configuration
- D. All of these options are correct
Explanation: The products of SN1 reactions can be formed with 50% retention and 50% inversion in configuration.
Correct answer: 50% retention and 50% inversion in configuration- A. Alkyl bromide
- B. Alkyl fluoride
- C. Alkyl chloride
- D. Alkyl iodide
Explanation: Alkyl iodide (alkyl iodides) is the most reactive towards a magnesium (Mg) atom in a reaction known as the Grignard reaction.
Correct answer: Alkyl iodide