(Polar molecules, Non-polar molecules, etc.)

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Postby Andrea_Torres » Sun Nov 17, 2019 6:20 pm

How does repulsion help influence the molecular shape?

Aarja Pavade 1H
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Re: Repulsion

Postby Aarja Pavade 1H » Sun Nov 17, 2019 6:22 pm

Repulsion influences the molecular shape as it can force bonding electrons closer together, reducing their bond angle. For instance, a molecule with a tetrahedral shape has bond angles of 109.5 but once lone pairs are introduced, there is greater repulsion and the bond angles decrease to <109.5 with a shape of trigonal pyramidal or bent.
Last edited by Aarja Pavade 1H on Sun Nov 17, 2019 6:25 pm, edited 1 time in total.

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Re: Repulsion

Postby Jiyoon_Hwang_2I » Sun Nov 17, 2019 6:24 pm

Usually, lone pairs cause more repulsion, so the bond angle decreases. For example, NH3 has 1 lone pair on nitrogen and its bond angle is 107 degrees, but H2O has 2 lone pairs and the bond angle is 104.5 degrees. So, the more lone pair electrons on the central atom, the more repulsion, causing the bond angle to decrease.

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