Question

Arrange the following in decreasing order of dipole moment
(a) Toluene (2) m-Dichlorobenzene
(3) o-Dichlorobenzene (4) p-Dichlorobenzene
(b) BF_(3) (2) `H_(2)S` (3) `H_(2)O`
(c ) cis-1 Chloropropene
(2) Trans -1 -Chloropropene
(3) 1,1-Dichloroethene .
A. `BF_(3) lt H_(2)S lt H_(2)O`
B. `H_(2)S lt BF_(3)ltH_(2)O`
C. `H_(2)O lt H_(2)S lt BF_(3)`
D. `BF_(3) lt H_(2)O lt H_(2)S`

Answer 1

Correct Answer - A
In `BF_(3)`, dipole moment is zero due to its symmetrical structure. Summations of all dipoles is zero.

In `H_(2)S and H_(2)O` due to unsymmetrical structure net + ve dipole is there `H_(2)O` has higher dipole due to higher electronegativity of oxygen than sulphur.