Haloalkanes And Haloarenes: Chemistry Quiz!
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On treatment with ethanolic KOH, 1–chlorobutane gives:
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1–Butene only
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2–Butene only
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2–Butanol
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A mixture of But–1–ene and But–2–ene
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Dive into the intriguing world of haloalkanes and haloarenes with this Chemistry Quiz! Explore reactions, properties, and comparisons through specific questions designed to enhance your understanding and skills in organic chemistry.
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- 2.
Which of the following compound has the highest density?
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C2H5I
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C2H5Br
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C2H5Cl
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C2H5F
Correct Answer
A. C2H5IExplanation
The density of a compound is determined by the mass of its molecules and the volume they occupy. In this case, the compound with the highest density is C2H5I. This is because iodine (I) is a heavier element compared to bromine (Br), chlorine (Cl), and fluorine (F). The larger atomic mass of iodine contributes to a higher overall molecular mass for C2H5I, resulting in a higher density.Rate this question:
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- 3.
In a group of isomeric alkyl halides the order of boiling points is:
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3o > 2o > 1o
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3o > 2o < 1o
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3o < 2o < 1o
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3o < 2o > 1o
Correct Answer
A. 3o < 2o < 1oExplanation
The order of boiling points in a group of isomeric alkyl halides is determined by the size and branching of the alkyl groups attached to the halogen atom. The more branching there is in the alkyl groups, the lower the boiling point. This is because branching reduces the surface area available for intermolecular interactions, leading to weaker Van der Waals forces between molecules. Therefore, the correct order is 3o < 2o < 1o, with the least branched alkyl halide having the highest boiling point.Rate this question:
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- 4.
Benzene on reaction with chlorine in the presence of sunlight gives:
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Chlorobenzene
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BHC
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DDT
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P-dichlorobenzene
Correct Answer
A. BHCExplanation
Benzene on reaction with chlorine in the presence of sunlight gives BHC. BHC stands for benzene hexachloride, which is a pesticide commonly used to control insects. The reaction involves the substitution of hydrogen atoms in benzene with chlorine atoms, resulting in the formation of BHC. It is important to note that the other options mentioned (Chlorobenzene, DDT, and p-dichlorobenzene) are not the correct products of this reaction.Rate this question:
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- 5.
Chlorobenzene is formed when one molecule of chlorine reacts in the presence of iron with:
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Benzene
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Toluene
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Benzene hexachloride
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Acetylene
Correct Answer
A. BenzeneExplanation
Chlorobenzene is formed when one molecule of chlorine reacts in the presence of iron with benzene.Rate this question:
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- 6.
The side chain chlorination of toluene takes place in the presence of:
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Halogen carrier
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Cl2/FeCl3
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Cl2/heat and light
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Cl2 in the presence of air
Correct Answer
A. Cl2/heat and lightExplanation
The side chain chlorination of toluene takes place in the presence of Cl2/heat and light. Chlorine gas (Cl2) acts as the chlorinating agent, while heat and light provide the necessary energy to initiate the reaction. The heat and light energy breaks the Cl2 molecule into highly reactive chlorine radicals, which then attack the toluene molecule and replace one of the hydrogen atoms in the side chain with a chlorine atom. This reaction is an example of a free radical substitution reaction and is commonly used to introduce chlorine atoms into organic compounds.Rate this question:
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- 7.
Which reagent will you use for the following reaction?
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Cl2/UV light
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NaCl + H2SO4
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Cl2 gas in dark
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Cl2 gas in the presence of iron in dark
Correct Answer
A. Cl2/UV lightExplanation
The reaction described in the question involves the use of chlorine gas (Cl2) and UV light. UV light is required to initiate the reaction between the chlorine gas and the other reactants. Therefore, the reagent that should be used for this reaction is Cl2/UV light.Rate this question:
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- 8.
Toluene reacts with a halogen in the presence of Iron (III) chloride giving ortho and para halo compounds. The reaction is:
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Elelctrophilic elimination reaction
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Elelctrophilic substitution reaction
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Free radical addition reaction
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Nucleophilic elimination reaction
Correct Answer
A. Elelctrophilic substitution reactionExplanation
Toluene reacts with a halogen in the presence of Iron (III) chloride, which acts as a catalyst. In electrophilic substitution reactions, a hydrogen atom in the benzene ring is replaced by an electrophile. In this case, the halogen acts as the electrophile, attacking the benzene ring and substituting one of the hydrogen atoms. This reaction is known as electrophilic substitution because an electrophile is involved in the reaction. Therefore, the correct answer is electrophilic substitution reaction.Rate this question:
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- 9.
Chlorobenzene is formed by reaction of chlorine with benzene in the presence of AlCl3. Which or the following species attacks the benzene ring in this reaction?
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Cl–
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Cl+
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AlCl3
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[AlCl4]–
Correct Answer
A. Cl+Explanation
In the reaction between chlorine and benzene in the presence of AlCl3, the species that attacks the benzene ring is Cl+. Chlorine is initially activated by AlCl3 to form Cl+ which is an electrophile. This electrophilic species then attacks the benzene ring, leading to the substitution of one of the hydrogen atoms in benzene with a chlorine atom, resulting in the formation of chlorobenzene.Rate this question:
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- 10.
Which of the following alcohols will yield the corresponding alkyl chloride on reaction with concentrated HCI at room temperature?
Correct Answer
A.Explanation
The correct answer is tertiary alcohol. Tertiary alcohols are more reactive towards nucleophilic substitution reactions compared to primary and secondary alcohols. When reacted with concentrated HCl at room temperature, tertiary alcohols undergo an SN1 mechanism, where the alcohol molecule is protonated by HCl to form a carbocation intermediate. The chloride ion then attacks the carbocation, resulting in the formation of the corresponding alkyl chloride. Primary and secondary alcohols, on the other hand, undergo SN2 mechanism, which requires a stronger nucleophile and higher temperatures.Rate this question:
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- 11.
A primary alkyl halide would prefer to undergo_____.
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SN1 reaction
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SN2 reaction
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α–Elimination
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Racemisation
Correct Answer
A. SN2 reactionExplanation
A primary alkyl halide would prefer to undergo SN2 reaction because SN2 reactions occur in a single step and involve a backside attack by the nucleophile on the carbon center, resulting in inversion of stereochemistry. Primary alkyl halides have less steric hindrance compared to secondary or tertiary alkyl halides, allowing the nucleophile to approach the carbon center more easily. Additionally, primary alkyl halides have a lower energy barrier for the transition state, making SN2 reactions more favorable.Rate this question:
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- 12.
Which of the following structures is enantiomeric with the molecule (A) given below:
Correct Answer
A. -
- 13.
Molecules whose mirror image is non-superimposable over them are known as chiral. Which of the following molecules is chiral in nature?
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2-Bromobutane
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1-Bromobutane
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2-Bromopropane
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2 Bromopropan-2-ol
Correct Answer
A. 2-BromobutaneExplanation
2-Bromobutane is chiral because it contains a chiral carbon atom, which is a carbon atom bonded to four different groups. The presence of this chiral center means that the molecule exists in two non-superimposable mirror image forms, or enantiomers. Therefore, 2-Bromobutane is considered a chiral molecule.Rate this question:
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- 14.
Which is the correct increasing order of boiling points of the following compounds? 1-Bromoethane, 1-Bromopropane, 1-Bromobutane, Bromobenzene
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Bromobenzene < 1-Bromobutane < 1-Bromopropane < 1-Bromoethane
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Bromobenzene < 1-Bromoethane < 1-Bromopropane < 1-Bromobutane
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1-Bromopropane < 1-Bromobutane < 1-Bromoethane < Bromobenzene
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1-Bromoethane < 1-Bromopropane < 1-Bromobutane < Bromobenzene
Correct Answer
A. 1-Bromoethane < 1-Bromopropane < 1-Bromobutane < BromobenzeneExplanation
The correct increasing order of boiling points is 1-Bromoethane < 1-Bromopropane < 1-Bromobutane < Bromobenzene. This is because the boiling point of a compound is determined by its intermolecular forces. Bromobenzene has the weakest intermolecular forces (London dispersion forces) due to its aromatic structure, so it has the lowest boiling point. 1-Bromobutane has stronger intermolecular forces (dipole-dipole forces) due to its longer carbon chain, so it has a higher boiling point than bromobenzene. 1-Bromopropane has even stronger intermolecular forces (more polar bonds) due to the presence of a propyl group, so it has a higher boiling point than 1-bromobutane. 1-Bromoethane has the strongest intermolecular forces (hydrogen bonding) due to the presence of an ethyl group, so it has the highest boiling point.Rate this question:
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- 15.
Arrange the compounds in increasing order of rate of reaction towards Nucleophilic substitution:
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I < II < III
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I < III < II
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III < II < I
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II < III < I
Correct Answer
A. II < III < IExplanation
The correct answer is II < III < I. This is because the rate of reaction towards nucleophilic substitution is generally determined by the stability of the intermediate carbocation formed during the reaction. In compound II, the intermediate carbocation is stabilized by the presence of an electron-donating group (EDG) which increases the rate of reaction. In compound III, the intermediate carbocation is stabilized by resonance, which also increases the rate of reaction. In compound I, there is no stabilizing group present, resulting in the slowest rate of reaction. Therefore, the correct order is II < III < I.Rate this question:
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Current Version
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Mar 21, 2023Quiz Edited by
ProProfs Editorial Team -
Dec 27, 2013Quiz Created by
Tanmay Shankar
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