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 23 of 23
- A. CH3F
- B. CH3I
- C. CH3Cl
- D. CH3Br
Explanation: The carbon-halogen bond length is determined by the size of the halogen atom. The larger the halogen atom, the longer the bond length.
Correct answer: CH3F- A. (C2H2Cl2)2S
- B. (C2H4Cl2)2S
- C. (C2H3Cl2)2S
- D. (C2H4Cl)2S
Explanation: The correct formula for mustard gas is (C2H4Cl)2S. Mustard gas is a sulfur mustard with each carbon chain containing one chlorine atom…
Correct answer: (C2H4Cl)2S- A. CH3CH2CHO
- B. CH3CH2CH2OH
- C. CH3CH2COOH
- D. CH3CH2CH2Br
Explanation: This is called Lalaigne's test, which is done for the detection of halogens. While all the other options given do not have halogens.
Correct answer: CH3CH2CH2Br- A. R - I > R - Br > R - Cl > R - F
- B. R - Br > R - I > R - F > R - Cl
- C. R - F > R - Cl > R - Br > R - I
- D. R - Cl > R - I > R - Br > R - F
Explanation: Alkyl halides reactivity is influenced by the bond strength between the carbon (C) and halogen (X) atoms.
Correct answer: R - I > R - Br > R - Cl > R - F- A. Methyl chloride
- B. Methyl iodide
- C. Methyl bromide
- D. Both a and b
Explanation: For the same alkyl group the boiling points of haloalkanes are in the order RCl < RBr < RI, because with the increase in the size of…
Correct answer: Methyl iodide- A. Methyle chloride
- B. Methyle fluoride
- C. Methyle bromide
- D. Methyle iodide
Explanation: methyl iodide generally has the highest boiling point. Boiling point is a measure of how easily a compound changes from a liquid to a gas.
Correct answer: Methyle iodide- A. R-Br > R-CL > R-F > R-I
- B. R-Br > R-F > R-I > R-CI
- C. R-I > R-Br > R-Cl > R-F
- D. R-Cl > R-I > R-Br > R-F
Explanation: The reactivity of alkyl halides towards nucleophilic substitution reactions follows the order:R-I (alkyl iodide) > R-Br (alkyl bromide) >…
Correct answer: R-I > R-Br > R-Cl > R-F- A. RX+H
- B. RH+HX
- C. 2RX+2Na-R-R+2NX
- D. R-X Mg-RMX
Explanation: The reaction of RX with KCN is a neucleophilic substitution reaction, as CN is a nucleophile that attacks the electrophilic carbocation.
Correct answer: RH+HX- A. nucleophiles
- B. electrophiles
- C. carbon ions
- D. carbonium ions
Explanation: Electrophiles: Electrophiles are electron-deficient species that accept a pair of electrons to form a new chemical bond.
Correct answer: electrophiles- A. Neopentyl system
- B. Tertiary compound with no branch
- C. Secondary halides
- D. Primary compound with no branch at β- carbon
Explanation: Primary compounds with no branching at the β-carbon, are generally the most suitable for SN2 reactions.
Correct answer: Primary compound with no branch at β- carbon- A. AICI3
- B. CN
- C. H3O
- D. BF3
Explanation: AlCl3, H3O+ and BF3 are electrophiles, while CN is a nucleophile.
Correct answer: CN- A. +CH3
- B. +CH3CH₂
- C. (CH3)2 +CH
- D. (CH3)3C+
Explanation: Option D represents a tertiary carbonium ion, which is much more stable than primary or secondary carbonium ions.
Correct answer: (CH3)3C+- A. NH3
- B. OH
- C. CN-
- D. Br2
Explanation: Br₂ is not a nucleophile because:No Significant Negative Charge:Nucleophiles are electron-rich species that donate electrons.Br₂ is a…
Correct answer: Br2- A. Secondary amine
- B. Tertiary amine
- C. Quaternary ammonium salt
- D. Mixture of (a), (b) & (c)
Explanation: When primary amines are treated with alkyl halides, they undergo a series of nucleophilic substitution reactions.
Correct answer: Mixture of (a), (b) & (c)- A. C6 H5O
- B. H-O-
- C. NH3
- D. C2 H5 O-
Explanation: Nucleophilicity increases as the density of negative charge increases. An anion is always a better nucleophile than a neutral molecule, so…
Correct answer: H-O-- A. Electrophile
- B. Nucleophile
- C. Lewis base
- D. None
Explanation: An electron-deficient species is one that has a deficiency of electrons, making it "electron-seeking" or electron-loving.
Correct answer: Electrophile- A. Inversion only
- B. Retention only
- C. Equal inversion and retention
- D. More inversion and retention
Explanation: In SN1 reactions, the formation of a planar carbocation allows for nucleophilic attack from either side, resulting in both inversion and…
Correct answer: More inversion and retention- A. H2O
- B. AlCl3
- C. BF3
- D. Cl2
Explanation: A nucleophile is a species that donates a pair of electrons to form a covalent bond with an electrophile.
Correct answer: H2O