106http://targetiit.com/iit_jee_forum/posts/chemical_bonding_10157.html
sir please see Q4
Compare the ond angles between H2O,OF2, and Cl2O. Justify Your Answer.
-
UP 0 DOWN 0 0 6
6 Answers
62the lp-lp repulsion is the criterion here least....
F2O, Cl2O and H2O
In all of these cases the molecule is a tetrahedral with oxygen in the center,
It has 2 lone pairs on the two corners
and 2 bond pairs
The angle is determined by the repulsion between the different bond pairs and lone pairs
The strength of repulsion decreases in the manner;
lone pair-lone pair > lone pair-bond pair > bond pair-bond pair
The bond angle of X-O-X will be determined by the repulsion of the lone pairs and the bonding pairs. The more lone pair -bond pair repulsion increases the more the bonding angle increases.
The degree of this type of repulsion depends on the electronegativity of X.
Hydrogen is the least electronegative.
Thus the bonding pair of the O-H bond will be closer to O, resulting in a higher electron density near O at the site of the bond. This increases the repulsion with the lone pairs in the outer shell of oxygen and thus increases the bond angle.
For F it is the opposite; F is very electronegative and thus the electron density of the O-F bond near O is less than thatin O-H.
Thus the repulsion with the lone pairs of O is lower and the 2 lone pairs of O squeeze the two bonding pairs closer together so that the lone pairs themselves can be further away from each other.
Please Note: This explanation has been copied from some other source. But I think this si the best explanation possible.
106sir this question had come in BT test. in which they mentioned Cl2O having the highest bond angle because of steric factors Cl is large in size. Even I had thot what u have written (or copied) but they had marked it wrong. So can u please clarify this point?
1061i am expecting the bondangle of OF2 will be greater.bcos the bond length will be in the order H20>F2O>Cl2O so next the repulsion factor,in H2O the repulsion between the hydrogen atoms is lesser compared to F2O while comparing F2O and Cl2O the distance between the lone pair and lone pair is greater for Cl2O so repulsion will be lesser,and bond angle results lesser for Cl2O
3mmm actually sir,this is not perfectly chemistry sir,this is ur subject physics.How can we come nearer to u.:P