NEET and AIPMT NEET Chemistry Hydrocarbons MCQ Questions Solved


Which is the most suitable reagent among the following to distinguish compound (III) from rest of the compounds?                                                                                                 

I. CH3-CC-CH3

II. CH3-CH2-CH2-CH3

III. CH3-CH2-CCH

IV. CH3-CH=CH2

(a) Br2/CCl4                     (b) Br2/CH3COOH

(c)Alk.KMnO4                   (d) Ammonical AgNO3

Concept Videos :-

#12 | Differentiation: Alkanes, Alkenes & Alkynes
#13 | Differentiation: Assignment on Alkane to Alkyne
#18 | Addition Reaction: 1
#19 | Addition Reaction: 2
#6 | Chemical Properties of Alkane
#9 | Chemical Properties of Alkene:I
#10 | Reaction of Alkene:I
#11 | Reaction of Alkene:II
#14 | Preparation of Alkyne
#15 | Reaction of Alkyne:I

Concept Questions :-

Alkanes, Alkenes and Alkynes - Chemical Properties

(d) It may be noted that only the terminal alkynes react with ammonical silver nitrate. Therefore, this reaction can be used to distinguish between 1-alkynes and others such as alkane, alkenes and non-terminal alkynes.

     CH3-CH2-CCH + 2[Ag(NH3)2]NO3 CH3CH2CCAg

                                                                         white ppt.

Difficulty Level:

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Which of the following reagents will be able to distinguish between 1-butyne and 2-butyne?       

(a) NaNH2            (b) HCl             (c) O2                 (d) Br2

Concept Videos :-

#12 | Differentiation: Alkanes, Alkenes & Alkynes
#13 | Differentiation: Assignment on Alkane to Alkyne
#18 | Addition Reaction: 1
#19 | Addition Reaction: 2
#6 | Chemical Properties of Alkane
#9 | Chemical Properties of Alkene:I
#10 | Reaction of Alkene:I
#11 | Reaction of Alkene:II
#14 | Preparation of Alkyne
#15 | Reaction of Alkyne:I

Concept Questions :-

Alkanes, Alkenes and Alkynes - Chemical Properties

(a) NaNH2 is used to distinguish between 1-butyne and 2-butyne.

    CH3CH2CCHNaNH2CH3CH2CCNa  + 1/2 H2

     CH3-CC-H NaNH2No reaction

Difficulty Level:

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A compound is treated with NaNH2 to give sodium salt. Identify the compound.                      

(a) C2H2                  (b) C6H6

(c) C2H6                   (d) C2H4

Concept Videos :-

#12 | Differentiation: Alkanes, Alkenes & Alkynes
#13 | Differentiation: Assignment on Alkane to Alkyne
#18 | Addition Reaction: 1
#19 | Addition Reaction: 2
#6 | Chemical Properties of Alkane
#9 | Chemical Properties of Alkene:I
#10 | Reaction of Alkene:I
#11 | Reaction of Alkene:II
#14 | Preparation of Alkyne
#15 | Reaction of Alkyne:I

Concept Questions :-

Alkanes, Alkenes and Alkynes - Chemical Properties

(a) Sodamide is strong base, attract the more acidic hydrogen and gives sodium salt

  H-CC-H + NaNH2 H-CC-Na+    +  1/2 H2

                                    Sodium ethynide

Difficulty Level:

  • 63%
  • 14%
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The product of the reaction between 

 +(CH3)3COH ?

(1)             (2)        (3)           (4) 

Concept Videos :-

#20 | Aromatic Hydrocarbons
#21 | Reactions of Benzene
#22 | Reactions of Toluene
#26 | Set 4: Solved Problems

Concept Questions :-

Aromatic Hydrocarbons - Benzene - Structure, Preparation & Chemical Reactions

(1) Grignard reagent with any compound containing acid hydrogen forms a hydrocarbon.

Difficulty Level:

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The reaction of toluene with Cl2 in the presence of FeCl3 gives 'X' and reaction in presence of presence of light gives 'Y'. Thus 'X' and 'Y' are                                            

(a) X= benzal chloride, Y=o-chlorotoluene

(b) X=m-chlorotoluene, Y=p-chlorotoluene

(c) X=o and p-chlorotoluene, Y= trichloromethyl benzene

(d) X= benzyl hloride, Y=m-chlorotoluene

Concept Videos :-

#20 | Aromatic Hydrocarbons
#21 | Reactions of Benzene
#22 | Reactions of Toluene
#26 | Set 4: Solved Problems

Concept Questions :-

Aromatic Hydrocarbons - Benzene - Structure, Preparation & Chemical Reactions

(c) In the presence of halogen carrier, electrophilic substitution occurs, while in the presence of sunlight, substitution occurs at the side chain.

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What products are formed when the following compound is treated with Br2 in the presence of FeBr3?                                                                            

Concept Videos :-

#20 | Aromatic Hydrocarbons
#21 | Reactions of Benzene
#22 | Reactions of Toluene
#26 | Set 4: Solved Problems

Concept Questions :-

Aromatic Hydrocarbons - Benzene - Structure, Preparation & Chemical Reactions

(c) CH3 is an o/p-directing group, thus electrophilic substitution reaction of toluene.

        

Difficulty Level:

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When chlorine is passed through propene at 400°C, which of the following is formed?            

(a) PVC                         (b) Allyl chloride  

(c) Nickel chloride          (d) 1,2-dichloro ethane

Concept Videos :-

#12 | Differentiation: Alkanes, Alkenes & Alkynes
#13 | Differentiation: Assignment on Alkane to Alkyne
#18 | Addition Reaction: 1
#19 | Addition Reaction: 2
#6 | Chemical Properties of Alkane
#9 | Chemical Properties of Alkene:I
#10 | Reaction of Alkene:I
#11 | Reaction of Alkene:II
#14 | Preparation of Alkyne
#15 | Reaction of Alkyne:I

Concept Questions :-

Alkanes, Alkenes and Alkynes - Chemical Properties

(b) When chlorine gas is reacted with propene at high temperature (400°C), then substitution takes place in place of addition reaction. Hence, allyl chloride is formed.

 CH3-CH=CH2 + Cl2 400°CC|H2-CH=CH2 + HCl          Cl                                   

Difficulty Level:

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In Friedel-Craft's alkylation, besides AlCl3 the other reactants are                                     

(a) C6H6 + NH2

(b) C6H6 + CH4

(c) C6H6 + CH3Cl

(d) C6H6 + CH3COCl

Concept Videos :-

#20 | Aromatic Hydrocarbons
#21 | Reactions of Benzene
#22 | Reactions of Toluene
#26 | Set 4: Solved Problems

Concept Questions :-

Aromatic Hydrocarbons - Benzene - Structure, Preparation & Chemical Reactions

(c) Friedel-Craft's alkylation When benzene reacts with alkyl halide in presence of anhy. AlCl3, toluene is obtained. It is called Friedel-Craft's alkylation. Friedel-Craft's reaction is type of electrophilic substitution.

  C6H6 + CH3Cl Anhy.AlCl3C6H5CH3 + HCl

                                      Toluene

Difficulty Level:

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Benzene reacts with n-propyl chloride in the presence of anhydrous AlCl3 to give                    

(a) 3-propyl-1-chlorobenzene

(b) n-propyl benzene

(c) no reaction

(d) iso-propyl benzene

Concept Videos :-

#20 | Aromatic Hydrocarbons
#21 | Reactions of Benzene
#22 | Reactions of Toluene
#26 | Set 4: Solved Problems

Concept Questions :-

Aromatic Hydrocarbons - Benzene - Structure, Preparation & Chemical Reactions

(d) Electrophilic substitution reaction of Benzene ring.

 

Difficulty Level:

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When acetylene is passed through dil.H2SO4 in presence of HgSO4, the compound formed is

(a) ether                           (b) ketone

(c) acetic acid                    (d) acetaldehyde

Concept Videos :-

#12 | Differentiation: Alkanes, Alkenes & Alkynes
#13 | Differentiation: Assignment on Alkane to Alkyne
#18 | Addition Reaction: 1
#19 | Addition Reaction: 2
#6 | Chemical Properties of Alkane
#9 | Chemical Properties of Alkene:I
#10 | Reaction of Alkene:I
#11 | Reaction of Alkene:II
#14 | Preparation of Alkyne
#15 | Reaction of Alkyne:I

Concept Questions :-

Alkanes, Alkenes and Alkynes - Chemical Properties

(d) Hydration of alkyne, 

CHCH + H2OHg2+/H+TautomerisationCH3-CHO

Difficulty Level:

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