VSEPR......gr8 confusions....helP

[hassam]

Well tell me abt VSEPR and how it affects the shape and bond angles in A INTUTIVE WaY

 

[beacon_of_light]

The theory says that repulsiön b/w bond pair-bond pair is less than repulsion b/w lone pair-lone pair. So considrng carbon tetra chloride having 4 bond pairs, the bond pair electrons repel positioning the 4 Cl at 109 angle. Ammonia has 3 bond pairz n 1 lone pair, although its structure is also tetrahedral cnsidrng 4 electron pairz but due to greater repulsion b/w lone pair n bond pair, angle reduces to 107 and shape becomes pyramidal. Hope tht helpz

 

[hassam]

bt due to repulsion between bond pairs and lone-pair why the angle decreases???.....it doesnt sounds COOL to me.ithink it shud increase bcos repulsion means atoms will move far apart...i mean cn u elaborate this point

 

[Xenon]

the angle that is considered is that between the bond pair electrons only, due to stronger repulsion from the lone pair/s, the angle between two bond pair reduces. but surely the angle between the lone pair and the bond pair is greater than that between only bond pairs & again, the angle between the lone pairs should be more than that between a bond pair and lone pair.

 

[beacon_of_light]

If u considr water -->has two lone pairs...greater repulsion b/w the electron clouds of lone pairs, the angle b/w H-0-H goes to 105...
Ammonia has 1 lonepair.so repulsion b/w bond pair n lone pair is less than that of lonepairz.so angle increasz to 107...
Methane has four bondpairz...so there is least repulsion b/w bondpairz n angle increases to 109.
Hope u gt that

 

[hassam]

HURRAY....thankoo xenon and beacon of lyt ...i understood