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11th Standard Chemistry Basic Concept of Organic Reactions English Medium Free Online Test One Mark Questions with Answer Key 2020 - 2021

11th Standard

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Chemistry

Time : 00:20:00 Hrs
Total Marks : 20

    Answer all the questions

    20 x 1 = 20
  1. What is the hybridisation state of benzyl carbonium ion?

    (a)

    sp2

    (b)

    spd2

    (c)

    sp3

    (d)

    sp2d

  2. Which of the following species is not electrophilic in nature?

    (a)

    Cl+

    (b)

    BH3

    (c)

    H3O+

    (d)

    +NO2

  3. Hyper Conjugation is also known as

    (a)

    no bond resonance

    (b)

    Baker - nathan effect

    (c)

    both (a)and (b)

    (d)

    none of these

  4. Which of the following species does not exert a resonance effect?

    (a)

    C6H5OH

    (b)

    C6H5Cl

    (c)

    C6H5NH2

    (d)

    \({ C }_{ 6 }{ H }_{ 5 }\overset { + }{ N } { H }_{ 3 }\)

  5. Which of the following carbocation will be most stable?

    (a)

    Ph3C-+

    (b)

    \({ C }{ H }_{ 3 }-\overset { + }{ C } { H }_{ 2 }\)

    (c)

    \(\left( { CH }_{ 3 } \right) _{ 2 }-\overset { + }{ C } { H }\)

    (d)

    \(CH_{ 2 }=CH-\overset { + }{ C } { { H }_{ 2 } }\)

  6. Heterolytic fission of C-C bond results in the formation of

    (a)

    free radical

    (b)

    Carbanion

    (c)

    Carbocation

    (d)

    Carbanion and Carbocation

  7. Which of the following species does not acts as a nucleophile?

    (a)

    ROH

    (b)

    ROR

    (c)

    PCl3

    (d)

    BF3

  8. Which of the following is heterolytic compound?

    (a)

    Pyrrole

    (b)

    Furan

    (c)

    Thiophene

    (d)

    All of these

  9. The most stable carbanion is

    (a)

    CH3-CH2

    (b)

    CH2=CH

    (c)

    CH≡ C

    (d)

    (CH3)2-CH

  10. In -NO2, -NH2,-SO3H, the decreasing order of I II III -I effect is

    (a)

    I > II > III

    (b)

    I > III > II

    (c)

    III > II > I

    (d)

    III > I > II

  11. The nucleophile is not

    (a)

    Lewis base

    (b)

    Lewis acid

    (c)

    \({ H }_{ 2 }\overset { .. }{ \underset { .. }{ O } } \)

    (d)

    Carbanion

  12. Which of the following statements is not correct for a nucleophile?

    (a)

    Nuc1eophiles attack low electron density sites

    (b)

    Nucleophiles are not electron seeking

    (c)

    Nuc1eophiles is a Lewis acid

    (d)

    Ammonia is a nucleophile

  13. Assertion (A) : Phenol is less acidic than benzoic acid.
    Reason (R) : Phenoxide has less number of resonating structures that benzyl carboxylate ion.

    (a)

    Both A and R are true and R is the correct explanation of A.

    (b)

    Both A and R are true but R is not correct explanation of A.

    (c)

    A is true statement but R is false.

    (d)

    Both A and R are false.

  14. The electromeric effect is

    (a)

    Permanent effect

    (b)

    Temporary effect

    (c)

    p-electrons transfer in the effect

    (d)

    Both (b) and (c)

  15. Which one is incorrect match of reactions?

    (a)

    (b)

    \(C{ H }_{ 3 }-C{ H }_{ 2 }-Br\overset { aq.\quad KOH }{ \longrightarrow } C{ H }_{ 3 }-C{ H }_{ 2 }OH\) ⟶ Nucleophilic substitution reaction

    (c)

    (d)

    \(\left( C{ H }_{ 3 } \right) C-Cl\overset { \overset { + }{ H } }{ \longrightarrow } { \left( C{ H }_{ 3 } \right) }_{ 3 }C-C{ H }_{ 2 }+{ H }_{ 2 }O+{ Cl }^{ - }\) ⟶ Nucleophilic substitution reaction

  16. The stability of alkyl free radicals is due to

    (a)

    Hyperconjugation

    (b)

    +I effect

    (c)

    -I effect

    (d)

    Both a & b

  17. Which of the following compounds will not undergo Friedal-craft's reaction easily?

    (a)

    Xylene

    (b)

    Nitrobenzene

    (c)

    Toluene

    (d)

    Cumene

  18. Assertion (A): \(C{ H }_{ 3 }-\overset { + }{ C } H-C{ H }_{ 3 }\) has 6 hyper-conjugative hydrogens. While \(C{ H }_{ 3 }-\overset { + }{ C } H-C{ H }_{ 2 }-C{ H }_{ 3 }\) has 5 hyper-conjugative hydrogens.
    Reason (R): \(C{ H }_{ 3 }-\overset { + }{ C } H-C{ H }_{ 3 }\) is more stable than \(C{ H }_{ 3 }-\overset { + }{ C } H-C{ H }_{ 2 }-C{ H }_{ 3 }\)

    (a)

    Both A and R are true and R is the correct explanation of A.

    (b)

    Both A and R are true but R is not the correct explanation of A.

    (c)

    A is true but R is false.

    (d)

    Both A and R are false

  19. Assertion (A) : Phenol is less acidic than benzoic acid.
    Reason (R) : Phenoxide has less number of resonating structures than benzyl carboxylate ion.

    (a)

    Both A and R are true and R is the correct explanation of A.

    (b)

    Both A and R are true but R is not the correct explanation of A.

    (c)

    A is true but R is false.

    (d)

    Both A and R are false.

  20. Which one of the following is positively charged electrophiles?

    (a)

    CO2

    (b)

    AlCl3

    (c)

    BF3

    (d)

    RX

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