Organic Chemistry - DIPOLE MOMENT

1

rahul wadhwani ·2009-01-28 04:27:28

hey u have to take this order of dipole moment
CH₂Cl₂ >CHCl₃ >CCl₄ as C is sp³ hybridised so tetrahedral structure i will post the exact value obtained it is JEE asked probably in 02/03

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1

skygirl ·2009-01-27 07:02:28

arey i din tell its planar...

it IS tetrahedral ....

but even then,,,, dun u all think, in ch2cl2 the moment will be in a particular direction only

but in chcl3, it will be there in two opposite directions ...
so moment will decrease...

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1

gagar.iitk ·2009-01-27 07:03:06

yes skygirl there is a basic problem in ur approach for calculation of dipole moment in CHCl₃ upon calculating like u r doing the dipole moment of CH₃Cl will be lesser than the CH₂Cl₂ but it is not

the the free redical formed by the species breaking carbon and hydrogen is more and more stablised as no of chlorine atoms increasing by p pie -d pie making the structure planar and increasing the bond angle between Cl atoms so the D.M decreases as the cl atoms increases

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skygirl ·2009-01-27 07:06:01

my God! ...

this kinda of thots r faar above my reach in chemistry ... am sorry bhaiya :( but i din get you ...

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gagar.iitk ·2009-01-27 07:13:41

no skygirl this is very common q for iit jee and the only reason which can explain the D.M of the system is extent of hyperconjugation which is surely is not included in iit jee but even ur calculations were wrong taking all angles as 109 degree there is some mistake in visualising the object in three degree must go through the solid state chapter especially tetrahedral and octahedral void system
it will enhance ur visuals in 3 degree

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1

? ·2009-01-27 07:15:03

skygirl u are rite as far as the preparation for JEE is concerned !!

gagar.iit ....whats wrong in it ?....

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skygirl ·2009-01-27 07:19:11

okie bhaiya....

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1

gagar.iitk ·2009-01-27 07:39:17

sorry unique if i have offended u ... just trying to give a broader view

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1

voldy ·2009-01-27 19:25:11

gagar bhiaya is given right reason da. It's better to know the perfect concept than something wrongly , just bcoz we think it's out of syllabus . I feel we should not pertain ourselves to some xxam , but we should try to know why exactly it happens so . the concept is more important than the problem . no harm meant buddy . sry if it hurts .

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1

skygirl ·2009-01-27 22:51:38

very sorry to blabber all wrong things...

thanx to the ppl who corrected it ..

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1

? ·2009-01-27 06:52:32

yup skygirl ...but both of them are tetrahedral but in ch₂cl₂ it is quite directional !

but in case of chcl₃ , as three chlorine atoms pulls the electrons , the resultant force is distributed in a irregular manner

hence,its ch₂cl₂ :)

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JOHNCENA IS BACK ·2009-05-02 20:36:40

@22
the the free redical formed by the species breaking carbon and hydrogen is more and more stablised as no of chlorine atoms increasing by p pie -d pie making the structure planar and increasing the bond angle between Cl atoms so the D.M decreases as the cl atoms increases...............................Hmmmmmmmmmmm

then according to above explanation CCl₄ wud be almost planar.................but i don think it is so???????????

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1

ANKIT MAHATO ·2009-05-02 21:17:01

CH2Cl2 ..
look at the 3D geometry
and note that Cl atom pulls electrons whereas H atom gives electrons ...

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JOHNCENA IS BACK ·2009-05-04 03:25:17

srinath............plz reply to #31

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JOHNCENA IS BACK ·2009-05-07 07:08:37

@22
the the free redical formed by the species breaking carbon and hydrogen is more and more stablised as no of chlorine atoms increasing by p pie -d pie making the structure planar and increasing the bond angle between Cl atoms so the D.M decreases as the cl atoms increases...............................Hmmmmmmmmmmm

then according to above explanation CCl4 wud be almost planar.................but i don think it is so???????????

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1

voldy ·2009-05-07 07:30:22

@22 maane kya ???

post 22 ???

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JOHNCENA IS BACK ·2009-05-07 07:32:53

YUP THE THING WRITTEN THERE I HAVE POSTED IN MY POST ITSELF SRI

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JOHNCENA IS BACK ·2009-05-14 09:05:15

sri ????????

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19

Debotosh.. ·2009-08-05 10:24:33

CH2Cl2 >CHCl3 >CCl4

due to repulsion between chlorine atoms , the Cl-C-Cl bond angle increases and hence the cos{bond angle} decreases as a result of which the dipole moment as a whole decreases because dipole moment involves additive use of the cos value !!!
you cannot consider the cis or trans things but the actual tetrahedral structures have to be dealt with !!!