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### Repulsion strength and Bond Angles

Posted: Sun Nov 17, 2019 7:08 pm
If two different molecules were to have the same shape, for example trigonal planar, but one molecule has a lone pair, would the bond angles between the central atom and the bonding atoms be different then the angles on the other molecule without the lone pair?

### Re: Repulsion strength and Bond Angles

Posted: Sun Nov 17, 2019 7:11 pm
Yes because the molecule with the lone pair would create repulsion that would alter the degrees of the bond angles.

### Re: Repulsion strength and Bond Angles

Posted: Sun Nov 17, 2019 7:11 pm
Yes, the one with the lone pair on the central atom would have increased repulsion because the electron repulsion of lone pair-bonding pair is greater than the electron repulsion in bonding pair to bonding pair, so the one with the central atom would have decreased bond angles.

### Re: Repulsion strength and Bond Angles

Posted: Sun Nov 17, 2019 7:12 pm
The repulsion would be different which will lead to a difference in bond angles

### Re: Repulsion strength and Bond Angles

Posted: Sun Nov 17, 2019 7:12 pm
If one of the molecules has a lone pair, there would be an electron repulsion between the lone pair and the other atoms in the molecule. This would make the resulting bond angle become smaller than the bond angle in the molecule with no lone pairs. This would also change the molecular structure from trigonal planar to bent.

### Re: Repulsion strength and Bond Angles

Posted: Sun Nov 17, 2019 7:14 pm
The bond angles would be slightly affected by the lone pair of the molecule if it was located on the central atom. The lone pair would cause more repulsion and slight bending. Also if the molecules were both trigonal planar, but one of the molecules had a lone pair then that molecule would be a bent shape instead which has a bond angle of less than 120.

### Re: Repulsion strength and Bond Angles

Posted: Sun Nov 17, 2019 7:15 pm
Yes, lone pairs create more repulsion so the angle between the 2 bonded atoms would be smaller and the two angles between the lone pair and the other two atoms would be bigger.

### Re: Repulsion strength and Bond Angles

Posted: Sun Nov 17, 2019 7:20 pm
Since the repulsion strength of lone pairs are stronger than the repulsion strength of bonding pairs, the molecule with the lone pair will have more bent bond angles

### Re: Repulsion strength and Bond Angles

Posted: Sun Nov 17, 2019 7:47 pm
Yes since the molecule with the lone pair would alter the degrees of the bond angles.

### Re: Repulsion strength and Bond Angles

Posted: Sun Nov 17, 2019 8:09 pm
Does anyone know if we need to have all of the bond angles of each shape memorized for Test 2? Also on that note if we do, do we need to know by how many degrees a lone pair would affect the angle or just that it would make it smaller due to electron repulsion pushing down the other atoms. Thanks!

### Re: Repulsion strength and Bond Angles

Posted: Sun Nov 17, 2019 8:10 pm
Yes, the lone pair repels the other bonds, causing the bond angle between them to be slightly less than what is expected.

### Re: Repulsion strength and Bond Angles

Posted: Sun Nov 17, 2019 8:16 pm
So we have to have all of the angles and possible lone pair induced angles memorized for test 2?

### Re: Repulsion strength and Bond Angles

Posted: Sun Nov 17, 2019 9:13 pm
brennayoung wrote:Does anyone know if we need to have all of the bond angles of each shape memorized for Test 2? Also on that note if we do, do we need to know by how many degrees a lone pair would affect the angle or just that it would make it smaller due to electron repulsion pushing down the other atoms. Thanks!

No, we don't need to know exactly how many degrees a lone pair would be effected but just know to label it on the test as greater than or less than the usual degree if the lone pair is present.