Alcohols and Ethers - Result Question 9

12. The acidic hydrolysis of ether $(X)$ shown below is fastest when

(2014 Adv.)

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(a) one phenyl group is replaced by a methyl group

(b) one phenyl group is replaced by a para-methoxyphenyl group

(c) two phenyl groups are replaced by two para-methoxyphenyl groups

(d) no structural change is made to $X$

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Answer:

Correct Answer: 12. (c)

Solution:

  1. This problem can be solved by using the concept of stability of carbocation and $S _N 1$ reaction.

When two phenyl groups are replaced by two para methoxy group, carbocation formed will be more stable. As the stability of carbocation formed increases, rate of acidic hydrolysis increases.

<img src=“https://temp-public-img-folder.s3.amazonaws.com/sathee.prutor.images/sathee_image/cropped_2024_01_16_b4fdca9f34924034e8d8g-359_jpg_height_454_width_776_top_left_y_1739_top_left_x_323.jpg"width="450">

Hence, (c) is the correct choice.