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

11th Standard

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Chemistry

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

20 x 1 = 20
1. For the following reactions
(A) CH3CH2CH2Br + KOH → CH2 = CH2 + KBr + H2O
(B) (CH3)3CBr + KOH → (CH3)3 COH + KBr
(C)
Which of the following statement is correct?

(a)

(A) is elimination, (B) and (C) are substitution

(b)

(A) is substitution, (B) and (C) are elimination

(c)

(A) and (B) are elimination and (C) is addition reaction

(d)

(A) is elimination, B is substitution and (C) is addition reaction

2. Homolytic fission of covalent bond leads to the formation of

(a)

electrophile

(b)

nucleophile

(c)

Carbo cation

(d)

3. Which of the group has highest +I effect?

(a)

CH3-

(b)

CH- CH-

(c)

(CH3)2 - CH-

(d)

(CH3)3 - C-

4. -I effect is shown by

(a)

-Cl

(b)

-Br

(c)

both (a) and (b)

(d)

-CH3

5. Assertion: Tertiary Carbocations are generally formed more easily than primary Carbocations ions.
Reason: Hyper conjugation, as well as inductive effect due to additional alkyl group, stabilize tertiary carbonium ions.

(a)

both assertion and reason are true and reason is the correct explanation of assertion

(b)

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

(c)

Assertion is true but reason is false

(d)

Both assertion and reason are false

6. The geometrical shape of carbocation is

(a)

Linear

(b)

tetrahedral

(c)

Planar

(d)

Pyramidal

7. In which of the following homolytic bond fision takes place?

(a)

Alkaline hydrolysis of ethyl chloride

(b)

Addition of HBr to double bond

(c)

Photochlorination of methane

(d)

Nitration of benzene

8. Which of the following represents the correct order of stability of the given carbocations?

(a)

III > I > II

(b)

I > III > II

(c)

III > II > I

(d)

II > III > I

9. The most stable alkene is

(a)

CH2=CH-CH2-CH3

(b)

$C{ H }_{ 2 }=\underset { \overset { | }{ C{ H }_{ 3 } } }{ CH } =C{ H }_{ 2 }$

(c)

CH2=CH-CH=CH2

(d)

CH3-CH=CH-CH3

10. : CH2 is an

(a)

Electrophile

(b)

Nucleophile

(c)

(d)

Ambiphiles

11. Assertion (A): Allyl carbanion ($C{ H }_{ 2 }=CH-\overset { \overset { - }{ .. } }{ C } { H }_{ 2 }$) is more stable than $\overset { \overset { - }{ .. } }{ C } { H }_{ 2 }-N{ O }_{ 2 }$
Reason (R): On $\overset { \overset { - }{ .. } }{ C } { H }_{ 2 }-N{ O }_{ 2 }$ , only -I effect of NO- group is present while is allyl carbanion, resonance is present.

(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.

12. The number of hyperconjugation structures possible in

(a)

3

(b)

2

(c)

6

(d)

None of these

13. Which one of the following is correct order of the stability of carbanions?

(a)

-C(CH3)3>-CH(CH3)2> -CH2-CH3 > -CH3

(b)

-CH3>-CH2-CH3> -CH(CH3)2> -(CH3)3

(c)

-CH(CH3)2>-H3 > -CH2-CH3 >-(CH3)3

(d)

-CH2-CH3>-CH(CH3)2>-CH3>-(CH3)3

14. Which one of the following is not nucleophile?

(a)

H2O

(b)

NH3

(c)

R-OH

(d)

FeCl3

15. Which one of the following is nucleophile?

(a)

BF3

(b)

AICl3

(c)

CO2

(d)

R-SH

16. Which one of the following species has tendency to show +1 effect?

(a)

-NH2

(b)

-CI

(c)

-C6H5

(d)

-CH3

17. Which one of the following has least acidic character?

(a)

HCOOH

(b)

CH3COOH

(c)

CH2CICOOH

(d)

CCl3COOH

18. Statement-I: Fluoro acetic acid is stronger acid than acetic acid
Statement-II: Fluorine has high electronegativity and it is facilitate to dissociate the O-H bond easily.

(a)

Statement-I and II are correct and statement-II is correct explanation of statement-I.

(b)

Statement-I and II are correct but statement-II is not correct explanation of statement-I.

(c)

Statement-I is correct but statement-II is wrong

(d)

Statement-I is wrong but statement-II is correct

19. Which one of the following electrophile used for nitration of benzene?

(a)

Br

(b)

NO2

(c)

-NH2

(d)

NOӨ

20. Primary alcohols undergo which type of reaction to form alkenes?

(a)

Elimination

(b)

Oxidation

(c)

Reduction

(d)

Hydrolysis