Bonding22

search old links....bahut baar ho chuka hai yeh...

I think b should b the correct answer but a is correct

How?:(

@ Eureka

:)

i posted this earlier also:
CH₃Cl>CH₂Cl₂ >CHCl₃ >CCl₄
here the trick lies in asserting that CHCl3has lesser dipole moment than CH3Cl !!!

let me compare between CH3Cl(1) and CHCl3(2)

the dipole moments in both 1 and 2 are additive(that can be shown by drawing the tetrahedral structures of the two compounds and then finding the directions of bond polarity for each bond). Cl tends to have a ∂- charge due its strong electro negativity and hence in 2 the Cl-Cl repulsion occurs as a result of which the Cl-C-Cl bond angle increases. we know that vector addition involves cos{bond angle}...hence as the bond angle increases the cosine value decreases and as a result the resultant dipole moment decreases !