NEETprep Bank NEET Chemistry Haloalkanes and Haloarenes Questions Solved


When CH3CH2CHCl2 is treated with NaNH2, the product formed is                             

(a) CH3-CH=CH2                     (b) CH3-CCH

(c) CH3CH2CH<NH2NH2                  (d) CH3CH2C<NH2Cl

(b) CH3-CH2-CHCl2 NaNH2(sodamide)CH3-CH=CHClNaNH2CH3-CCH

                                                                                      final product

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Chlorobenzene reacts with Mg in dry ether to give a compound (A) which further reacts with ethanol to yield                                                                                                       

(a) phenol                           (b) benzene

(c) ethyl benzene                (d) phenyl ether

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R-CH2-CCl2-R ReagentR-CC-R. The reagent is

(a) Na                                   (b) HCl in H2O

(c) KOH in C2H5OH                (d) Zn in alcohol

(c) Dehydrohalogenation reaction,

In presence of ethanolic KOH substrate gives an elimination reaction.

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Ethyl chloride is converted into diethyl ether by                                                  

(a) Wurtz reaction                           (b) Grignard reaction

(c) Perkin's reaction                         (d) Williamson's synthesis

(d) C2H5Cl - NaOC2H5 C2H5-O-C2H5 + NaCl

It is an example of Williamson's synthesis. Limitations of Williamson's synthesis if 3° alkyl halide used in reaction then alkene formed.

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The alkyl halide is converted into an alcohol by                                    

(a) addition                       (b) substitution

(c) dehydrohalogenation     (d) elimination

(b) RCl + NaOH(aq) ROH + NaCl

It is an example of nucleophilic substitution reaction.

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Addition of Br2 on cis-butene-2 gives:

(a) a racemic mixture of 2,3-dibromobutane

(b) meso form of 2,3-dibromobutane

(c) dextro form of 2,3-dibromobutane

(d) laevo form of 2,3-dibromobutane 

(a) Follow mechanism of addition reaction.

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The number of different substitution products possible when ethane is allowed to react with bromine in sunlight are:

(a) 9           (b) 6

(c) 8           (d) 5

(a) CH3CH2Cl; CH3CHCl2; CH2ClCH2Cl; CH3CCl3;CH2ClCHCl2; CH2ClCCl3; CHCl2CHCl2; CHCl2CCl3;

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CH3-CH2-C|H-CH3                      Cl obtained by chlorination of n-butane, will be                

(a) meso form              (b) racemic mixture

(c) d-form                 (d) l-form

(b) Chlorination of n-butane takes place by free radical mechanism as follows:

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In SN2 reactions, the correct order of reactivity for the following compounds : CH3ClCH3CH2ClCH32CHCl and CH33CCl is :

(a) CH3Cl>CH32CHCl>CH3CH2Cl>CH33CCl

(b) CH3Cl>CH3CH2Cl>CH32CHCl>CH33CCl

(c) CH3CH2Cl>CH3Cl>CH32CHCl>CH33CCl

(d) CH32CHCl>CH3CH2Cl>CH3Cl>CH33CCl

(b) Due to more -I.E. of attached groups in CH33CCl or due to max crowding round central carbon atom favours SN l mechanism.

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Action of RMgX with vinyl chloride gives:

(a) alkane                                  (b) alkyne

(c) alkene                                  (d) all of these

 

(c) RMgX +ClHC=CH2RCH=CH2 + 

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