Lone Pairs

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

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halle young 4A
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Lone Pairs

Postby halle young 4A » Wed Nov 13, 2019 9:24 pm

When a lone pair is present in a molecule, how do we know if it will increase or decrease the bond angle? or will either answer be correct?

ishaa Diwakar 4E
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Re: Lone Pairs

Postby ishaa Diwakar 4E » Wed Nov 13, 2019 9:26 pm

Since lone pairs take up more space, the bond angles adjacent to the lone pairs will increase and the opposing angles will decrease.

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Re: Lone Pairs

Postby Mashkinadze_1D » Wed Nov 13, 2019 9:26 pm

If a lone pair is present then it will decrease the angles because it causes more repulsion. However, if it is a smaller atom that is present for example change F to H, then the bond angles will decrease. In contrast, if it is larger like a H to F then they will decrease the angles just as in the lone pairs. Smaller angles would be much less stable.

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Re: Lone Pairs

Postby LBacker_2E » Thu Nov 14, 2019 9:34 am

Are the lone pairs always going to cause a bent shape, or will there be times when the lone pairs are opposite of each other?

Kayli Choy 2F
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Re: Lone Pairs

Postby Kayli Choy 2F » Thu Nov 14, 2019 10:13 am

There are times where lone pairs are opposite each other, and the repulsive forces cancel each other out. For instance, in molecules that have trigonal bipyramidal electron arrangement (6 bonding spots), with bonded atoms and 2 lone pairs, the lone pairs on the top and bottom of the molecule cancel each other out, so the resulting shape is square planar, not bent.

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Re: Lone Pairs

Postby TYun_1C » Thu Nov 14, 2019 10:17 am

There are many different structures that contain lone pairs. They are not only a bent shape-- this is the shape for a molecule with 2 bonds and one lone pair. It is a good idea to think that lone pairs will generally push the bonded atom away from it due to the fact that it takes up space but also because its negative charge causes repulsion.

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