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 Multiple Choice QuestionsMultiple Choice Questions

721.

The following sequence of reactions on A gives


722.

Nitrobenzene on treatment with zinc dust and aqueous ammonium chloride gives

  • C6H5N =N-C6H5

  • C6H5NH2

  • C6H5NO

  • C6H5NHOH.


723.

Among the following which one does not act as an intermediate in Hofmann rearrangement?

  • RNCO

  • RCON..

  • RCON..HBr

  • RNC


724.

Pyridine is less basic than triethylamine because

  • pyridine has aromatic character

  • nitrogen in pyridine is sp2 hybridised

  • pyridine is a cyclic system

  • in pyridine, lone pair of nitrogen is delocalised


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725.

Assertion: Anilinium chloride is more acidic than ammonium chloride.

Reason : Anilinium ion is resonance-stabilised.

  • If both assertion and reason are true and reason is the correct explanation of the assertion.

  • If both assertion and reason are true but reason is not the correct explanation of the assertion.

  • If assertion is true, but reason is false.

  • Both assertion and reason are false statements.


726.

Hinsberg's reagent is :


727.

In the reaction :

C6H5CHO + C6H5NH2  C6H5N=HCC6H5 + H2O, the compound C6H5N=HCC6H5 is known as :

  • aldol

  • Schiffs base

  • Schiff's reagent

  • Benedict's reagent


728.

IUPAC name of CH3-CH(CH2CH3)-CH2-CH(CN)-CH3 is :

  • 2-cyano-3-methylhexane

  • 2.4-dimethylhexanenitrile

  • 3-methyl-5-cyanohexane

  • 2-cyano-3-methylhexane


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729.

Aromatic nitriles (ArCN) are not prepared by reaction:

  • ArX + KCN

  • ArN2++ CuCN

  • ArCONH2+ P2O5

  • ArCONH2+ SOCl2


A.

ArX + KCN

Halogen have +I and +M effect by which its electron delocalized in benzene ring by resonance and due to its +I effect its bonded with benzene ring and cannot be substitute bt CN- and show the inertness against KCN while other option gives aromatic nitrile .            

ArN2+ + CuCN ArCN +N2 +Cu+ArCONH2 H2OP2O5 ArCNArCONH2 + SOCl2  ArCN + SO2 + 2HCl

                          OR

(Aryl halides (ArX) does not undergo nucleophilic substitution because they have strong Cbond due to resonance.)

 


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730.

Melting points are normally the highest for

  • tertiary amides

  • secondary amides

  • primary amides

  • amines.


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