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.
Last updated
Read the Alkyl Halides notesFree MDCAT chapter notes with key terms458 questions · page 3 of 23
- A. E1 - reaction
- B. E2 - reaction
- C. SN1 - reaction
- D. SN2 - reaction
Explanation: SN1 reactions form a planar carbocation intermediate, allowing nucleophilic attack from either side and producing approximately equal…
Correct answer: SN1 - reaction- A. NH3
- B. Br+
- C. H+
- D. BF3
Explanation: An electrophile accepts an electron pair, as H+, Br+ and BF3 do because they are electron-deficient.
Correct answer: NH3- A. Zero
- B. First
- C. Second
- D. Third
Explanation: SN1 means unimolecular nucleophilic substitution because the slow step involves only the substrate forming a carbocation; therefore, rate…
Correct answer: First- A. HSO4-
- B. Cl-
- C. OH-
- D. Br-
Explanation: A good leaving group is a stable ion after it departs, and hydroxide is a strong base, so OH- is a poor leaving group.
Correct answer: OH-- A. 1
- B. 2
- C. 3
- D. 4
Explanation: In the Wurtz reaction, methyl iodide and ethyl iodide couple in three ways: methyl with methyl gives ethane, methyl with ethyl gives…
Correct answer: 3- A. E1 mechanism- strong base and alkyl halide, E2 mechanism- weak base and alkyl halide
- B. E1 mechanism- weak base and alkyl halide, E2 mechanism- strong base and alkyl halide
- C. E1 mechanism- strong base and alkyl halide, E2 mechanism- strong base and alkyl halide
- D. E1 mechanism- weak base and alkyl halide, E2 mechanism- weak base and alkyl halide
Explanation: E1 mechanism- weak base and alkyl halide, E2 mechanism- strong base and alkyl halide.In the E1 mechanism, the rate-determining step is the…
Correct answer: E1 mechanism- weak base and alkyl halide, E2 mechanism- strong base and alkyl halide- A. 1o alkyl halide
- B. 2o alkyl halide
- C. 3o alkyl halide
- D. 4o alkyl halide
Explanation: An alkyl halide is classified based on the number of carbon atoms attached to the carbon atom bearing the halogen.
Correct answer: 1o alkyl halide- A. BF3
- B. AlCl3
- C. SO3
- D. CN
Explanation: A nucleophile is a species that donates a pair of electrons to form a covalent bond.
Correct answer: CN- 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 + HCI- A. CH3CONH2
- B. CH3CH2NH2
- C. (CH3)2CHCO2H
- D. CH3CH2CO2H
- E. CH3CH2OH
Explanation: The hydrolysis of nitrile produces carboxylic acid. Since the number of carbons given in our question is 3 so the correct answer should be…
Correct answer: CH3CH2CO2H- A. Propogation
- B. Free radical substitution
- C. Addition
- D. Elimination
Explanation: Free-radical halogenation is a type of halogenation. This chemical reaction is typical of alkanes and alkyl-substituted aromatics under…
Correct answer: Free radical substitution- A. O - toluidine
- B. M - toluidine
- C. P- toluidine
- D. P-chloroaniline
Explanation: We know that the reaction of p-chlorotoluene with KNH2 in liquid NH3 proceeds via the benzyne mechanism.
Correct answer: M - toluidine- A. RF > RCl > RBr > RI
- B. RF > RBR > RCl > RI
- C. RCl > RBr > RF > RI
- D. RI > RBr > RCl > RF
Explanation: The reactivity of the alkyl halide in the SN2 reaction is decided by the ease with which the halide leaves the substrate.
Correct answer: RI > RBr > RCl > RF- A. Grignard's Reagent
- B. Baeyer's Reagent
- C. Ether
- D. Ester
- E. Aldehyde
Explanation: A Grignard reagent of the Grignard compound is a chemical compound with the generic formula R−Mg−X, where X is a halogen and R is an…
Correct answer: Grignard's Reagent- A. Concentrated HNO3/Concentrated H2SO4/100˚C
- B. Concentrated HNO3/Concentrated H2SO4/50˚C
- C. Concentrated HNO3/50˚C
- D. Concentrated HNO3/100˚C
- E. Concentrated HNO3/Concentrated HCl/50˚C
Explanation: Nitration happens when one (or more) of the hydrogen atoms on the benzene ring is replaced by a nitro group, NO2.
Correct answer: Concentrated HNO3/Concentrated H2SO4/50˚C- A. An metamerism of the substrate
- B. A product with opposite optical rotation
- C. A mixture of diastereomers
- D. A single stereoisomer
- E. The same product
Explanation: An SN2 reaction at an asymmetric C of a compound always gives a product with opposite optical rotation.
Correct answer: A product with opposite optical rotation- A. 5% methyl alcohol ... negative
- B. 2% Ethyl alcohol ... negative
- C. V2O5 ... positive
- D. Al2O3 ..... negative
Explanation: The catalyst in the above reaction is 2% ethyl alcohol with negative nature.
Correct answer: 2% Ethyl alcohol ... negative- A. Positive catalyst
- B. Negative catalyst
- C. Auto catalyst
- D. Both A and B
Explanation: If a product of the reaction acts as a catalyst, then such a catalyst is called an autocatalyst.
Correct answer: Auto catalyst- A. -NH2
- B. -OH
- C. -X (halogens)
- D. -R (alkyl groups)
Explanation: Halides are ortho-para- directing groups but unlike most ortho-para- directors halides tend to deactivate benzene.
Correct answer: -X (halogens)- A. R-CI
- B. R-F
- C. R-Br
- D. R-I
Explanation: To react with the alkyl halides, the carbon-halogen bond has gotten to be broken.
Correct answer: R-F