The correct sequece of dipole moment among the chlorides of methane is

Options

A. `CHCl_(3) gt CH_(2)Cl_(2) gt CH_(3)Cl gt C Cl_(4)`
B. `CH_(2)Cl_(2) gt CH_(3)Cl gt CHCl_(3) gt C Cl_(4)`
C. `CH_(3)Cl gt CH_(2)Cl_(2) gt CHCl_(3) gt C Cl_(4)`
D. `CH_(2)Cl_(2) gt CHCl_(3) gt CH_(3)Cl gt C Cl_(4)`

Answer

a

Explanation

`mu_(C Cl_(4))=0`
`mu_(Coverset(rarr) -Cl) " " mu_(Hoverset(rarr)-C)=0.4D`

The resultant dipole moment of three `C - H` bonds `= 0.4 D`.
Net dipole moment `= 1.9 D`
The resultant dipole two `C- H` bonds
`= sqrt((0.4)^(2) + (0.4)^(2) + 2 xx (0.4)^(2) xx cos 109.5^(@))`
`sqrt(0.16 + 0.16 - 0.2873) = 0.18 D`
The resultant of two `C - CI` bonds
`sqrt((1.5)^(2) + (1.5)^(2) + 2 xx (1.5)^(2) cos 109.5^(@))`
`= sqrt(2.25 + 2.25 + 2 xx 2.25 xx cos 109.5^(@))`
`sqrt(4.5 - 4.04) = sqrt(0.46) = 0.678`
`:. mu_(cal) = 0.855 D` but experimentaly for `CH_(2)CI_(2). mu = 1.59 D`
The resultant of three `C- CI bonds = 1.5 D`
Experimental dipole moment of `CHCl_(3)=1.15 D`