Question

Order of dipole moment for a) 1,2 dichlorobenzene
b) 1,3 dichlorobenzene
c) 1,4 dichlorobenzene ​

Answer 1

Answer:

The order of dipole moment is as follows:

1,2--dichlorobenzene > 1,3-dichlorobenzene > 1,4-dichlorobenzene

Since two Cl groups in ortho make an acute angle, according to the equation-

Dipole moment D=

(d

1

2

+d

2

2

+2d

1

d

2

×cosx)

[where x is the angle between the groups]

Thus, 1,3-dichlorobenzene has lesser moment than 1,2--dichlorobenzene and 1,4-dichlorobenzene has 0 dipole moment as cos 90

o

=0.

Hence, option A is correct.