Question

Dipole moment of p-nitroaniline, when compared to
nitrobenzene (X) and aniline (Y) will be :
(a) smaller than both (X) and (Y)
(b) greater than both (X) and (Y)
(c) greater than (Y) but smaller than (X)
(d) equal to zero

Answer 1

Greater than both (X) and (Y) is the correct answer.

Explanation:

• The nitro group is a - R and - I group that draws huge pool of electrons from benzene ring.

• It is because the nitro group is formed of 2 oxygen and 1 nitrogen atoms, all of which are highly electronegative atoms.

• On the other hand, amino group is a +R and +I group which pushes electrons in benzene ring.

• This is because even though nitrogen is present in amino group, it has the lone pair of electrons which take part in the resonating structure of benzene.

• So in nitrobenzene, the dipole moment is upwards because of the electron pull.

• In amino benzene, the dipole moment will be downwards because of the electron push.

• So in p-nitroaniline, the electron will be pulled from bottom and pushed from top.

• So the resultant dipole moment will be obviously greater than both individually, somewhere close to addition of both the values.

For more information about +R and +I effects,

https://brainly.in/question/4998296What is +R and -R effects in whic h electron density is less and more

https://brainly.in/question/3039514

what is I and R effect in chemistry? - Brainly.in