Q45 of 51 Page 169

In the following questions a statement of assertion (A) followed by a statement of reason (R) is given. Choose the correct option out of the choices given below each question.

Assertion (A) : Toluene on Friedal Crafts methylation gives o– and p–xylene.


Reason (R) : CH3- group bonded to benzene ring increases electron density at o– and p– position.


(i) Both A and R are correct and R is the correct explanation of A.


(ii) Both A and R are correct but R is not the correct explanation of A.


(iii) Both A and R are not correct.


(iv) A is not correct but R is correct.


Correct option - (i)Both A and R are correct and R is the correct explanation of A.


•CH3 group in toluene increase the electron density at o- and p- position of benzene ring. Because CH3 group in toluene act as +M effect containing group so, if act as ortho and para directing group for upcoming electrophile.


•Friedal Craft methylation is an electrophilic substitution reaction on benzene ring.


•Hence electrophile attacks at o- and p- postion of benzene ring.



More from this chapter

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43

Match the reactions given in Column I with the reaction types in Column II


 44

In the following questions a statement of assertion (A) followed by a statement of reason (R) is given. Choose the correct option out of the choices given below each question.

Assertion (A) : The compound cyclooctane has the following structural formula :



It is cyclic and has conjugated 8π-electron system but it is not an aromatic compound.


Reason (R) : (4n + 2) π electrons rule does not hold good and ring is not planar.


(i) Both A and R are correct and R is the correct explanation of A.


(ii) Both A and R are correct but R is not the correct explanation of A.


(iii) Both A and R are not correct.


(iv) A is not correct but R is correct.


 46

In the following questions a statement of assertion (A) followed by a statement of reason (R) is given. Choose the correct option out of the choices given below each question.

Assertion (A) : Nitration of benzene with nitric acid requires the use of concentrated sulphuric acid.


Reason (R) : The mixture of concentrated sulphuric acid and concentrated nitric acid produces the electrophile, NO2+ .


(i) Both A and R are correct and R is the correct explanation of A.


(ii) Both A and R are correct but R is not the correct explanation of A.


(iii) Both A and R are not correct.


(iv) A is not correct but R is correct.


 47

In the following questions a statement of assertion (A) followed by a statement of reason (R) is given. Choose the correct option out of the choices given below each question.

Assertion (A) : Among isomeric pentanes, 2, 2-dimethylpentane has highest boiling point.


Reason (R) : Branching does not affect the boiling point.


(i) Both A and R are correct and R is the correct explanation of A.


(ii) Both A and R are correct but R is not the correct explanation of A.


(iii) Both A and R are not correct.


(iv) A is not correct but R is correct.