Multiple Choice QuestionsWhich one of these is not true for benzene?
It forms only one type of monosubstituted product
There are three carbon-carbon single bonds and three carbon-carbon double bonds
Heat of hydrogenation of benzene is less than its theoretical value
The bond angle between carbon-carbon bonds is 120°
A dibromo derivative of an alkane reacts with sodium metal to form an alicyclic hydrocarbon. The derivative is
1, 1-dibromopropane
2, 2-dibromobutane
1, 2-dibromoethane
1, 4-dibromobutane
Which one of the following is an intermediate in the reaction of benzene with CH3Cl in the presence of anhydrous AlCl3?
Cl-
CH
CH
Cycloalkane formed when 1,4-dibromopentaneis heated with sodium is
methyl cyclobutane
cyclopentane
cyclobutane
methyl cyclopentane
Methane can be converted into ethane by the reactions
chlorination followed by the reaction with alcoholic KOH
chlorination followed by the reaction with aqueous KOH
chlorination followed by Wurtz reaction
chlorination followed by decarboxylation
Least energetic conformation of cyclohexane is
chair conformation
boat conformation
cis conformation
E-Z form
An alkyl bromide (X) reacts with sodium in ether to form 4,5-dIethyl octane, the compound X is
CH3(CH2)3Br
CH3(CH2)5Br
CH3(CH2)3CH(Br)CH3
CH3—(CH2)2—CH(Br)—CH2—CH3
The correct sequence of reactions to be performed to convert benzene into m-bromoaniline is
nitration, reduction, bromination
bromination, nitration, reduction
nitration, bromination, reduction
reduction, nitration, bromination
The correct statement is
Cyclohexadene and cyclohexene cannot be isolated with ease during controlled hydrogenation of benzene
One mole each of benzene and hydrogen when reacted gives 1/3 mole of cyclohexane and 2/3 mole unreacted hydrogen
Hydrogenation of benzene to cyclohexane is an endothermic process
It is easier to hydrogenate benzene when compared to cyclohexene
A.
Cyclohexadene and cyclohexene cannot be isolated with ease during controlled hydrogenation of benzene
On controlled hydrogenation of benzene with group I metal (like Na, Li) and methanol (or ethanol) in liquid NH3, it reduces into cyclohexadiene and cyclohexene, which cannot be isolated.
This is because the presence of reducing agent hexadene is further reduced to hexene hence, statement (a) is correct. Statement (b) is incorrect due to data insufficiency. Statement (d) is incorrect because benzene is a stable aromatic compound while cycloohexene can be easily hydrogenated due reactive double bond. So correct choice is (a).
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