bond angles

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

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Guzman_1J
Posts: 72
Joined: Wed Sep 18, 2019 12:16 am

bond angles

Postby Guzman_1J » Sat Dec 07, 2019 11:09 pm

Can someone explain how we knows what the bond angles are? I'm still confused about how we know that, or like how we know that an angle is less than some other angle(for example when they say that an angle is <120, how do they reach that conclusion)?

505306205
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Re: bond angles

Postby 505306205 » Sat Dec 07, 2019 11:15 pm

Bond angles will be less than the ideal structure due to lone pair and bond pair repulsion and/or lone-pair lone-pair repulsions.

Gwen Casillan Dis 1I
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Joined: Sat Sep 07, 2019 12:17 am

Re: bond angles

Postby Gwen Casillan Dis 1I » Sat Dec 07, 2019 11:20 pm

Bond angles were covered in lecture and can also be found in the textbook. Bond angles are affected by repulsion between electrons, with stronger repulsions between lone pair and lone pair electrons and weaker repulsions between bonded pair and bonded pair electrons.

Maika Ngoie 1B
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Joined: Fri Aug 02, 2019 12:16 am

Re: bond angles

Postby Maika Ngoie 1B » Sun Dec 08, 2019 6:33 pm

Lone pairs will make a bond angle less than (<) the angle of the shape it is derived from, because the electron repulsion from lone pairs condenses the angles of the bonds.

jisulee1C
Posts: 149
Joined: Thu Jul 25, 2019 12:17 am

Re: bond angles

Postby jisulee1C » Sun Dec 08, 2019 6:47 pm

Bond angles will depend on electrons and the molecular shape. Lone pair electrons have greater repulsion than bonded electrons and will therefore create a smaller bond angle.

JasonKwon_3k
Posts: 51
Joined: Thu Jul 11, 2019 12:16 am

Re: bond angles

Postby JasonKwon_3k » Sun Dec 08, 2019 7:05 pm

bond angles will be dependent on the electron arrangement and determining if they are less than a certain angle will be the effect of lone pairs.

David He
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Re: bond angles

Postby David He » Sun Nov 15, 2020 10:53 am

bonding angle is determined by the number of atoms in a molecule and the arrangement of atoms

LeanneBagood_2E
Posts: 41
Joined: Wed Sep 30, 2020 9:32 pm

Re: bond angles

Postby LeanneBagood_2E » Sun Nov 15, 2020 2:43 pm

though the explanations make some sense, im still a bit confused in the process of finding the actual value of a bonding angle. can someone possibly explain an example? maybe one of the ones from lecture?

AJForte-2C
Posts: 40
Joined: Wed Sep 30, 2020 10:00 pm

Re: bond angles

Postby AJForte-2C » Sun Nov 15, 2020 2:47 pm

If lone pairs have more repulsion power than a bond, how does a lone pair affect the bonding angles of a molecule? How would we calculate it?

Abraham De Luna
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Joined: Sat Sep 14, 2019 12:16 am

Re: bond angles

Postby Abraham De Luna » Sun Nov 15, 2020 9:54 pm

The bond angle will depend on the arrangement of electrons and molecular shape.

Libby Dillon - 1J
Posts: 42
Joined: Fri Oct 02, 2020 12:17 am

Re: bond angles

Postby Libby Dillon - 1J » Wed Nov 18, 2020 11:18 am

Bond angles can be generalized and predicted based on shape, but will slightly differ based on certain atoms. Also, lone pairs contain additional force which pushes bonding electron pairs closer together, making bond angles smaller. I do not think we have to be able to determine bond angles, but we should be aware what could make them smaller / be able to estimate based on shape.

Eunice_Castro_1G
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Joined: Wed Sep 30, 2020 9:46 pm

Re: bond angles

Postby Eunice_Castro_1G » Wed Nov 18, 2020 11:26 am

We are not required to know the bond angles, but we are able to tell if the bond angle will be less. If there are lone pairs, it will "squish" the bond angles, making the angle smaller.

Lorraine Jiang 3C
Posts: 47
Joined: Wed Sep 30, 2020 9:54 pm

Re: bond angles

Postby Lorraine Jiang 3C » Wed Nov 18, 2020 11:50 pm

I think we can predict the bond angles using the VSEPR theory, so for example how long-pairs repel each other more than lone-pairs repel a bonding pair. So if we have a lone-pair of electrons on the central atom we will know that the other atoms bonded to the central atom will be pushed down and the bond angles will change accordingly.

Hope it helps!

Mackenzie Stockton 2H
Posts: 41
Joined: Wed Sep 30, 2020 10:11 pm

Re: bond angles

Postby Mackenzie Stockton 2H » Thu Nov 19, 2020 3:49 pm

We can predict the bond angles using VSPR, which is based on electron electron repulsion between lone pair electrons and bonding pair electrons. In terms of finding the exact value of the bond angles, this may not be always known, as many times the angles are described as being "less than" a certain amount, in which we do not need to know the exact angle.

Mary Shih 3J
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Joined: Wed Sep 30, 2020 9:39 pm

Re: bond angles

Postby Mary Shih 3J » Thu Nov 19, 2020 6:13 pm

Guzman_1J wrote:Can someone explain how we knows what the bond angles are? I'm still confused about how we know that, or like how we know that an angle is less than some other angle(for example when they say that an angle is <120, how do they reach that conclusion)?


an angle may be smaller than 120 because there is a lone pair of electrons that will "push" the bonded electrons down and therefore, decrease the bond angles. the unpaired electrons have a negative charge that is repelling the electrons in the bonded pair, moving them and impacting the bond angle.Also remember lone pair electrons hold a larger volume in which that space has a negative charge. This is another factor that decreases bond angle

Catherine Bubser 2C
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Joined: Wed Sep 30, 2020 9:45 pm

Re: bond angles

Postby Catherine Bubser 2C » Fri Nov 20, 2020 10:43 am

If there are lone pairs causing the bod angles to deviate from their average measurements, will the new angles always be less than their average counterparts?

AustinMcBrideDisc3C
Posts: 43
Joined: Wed Sep 30, 2020 9:39 pm

Re: bond angles

Postby AustinMcBrideDisc3C » Fri Nov 20, 2020 12:57 pm

Professor Lavelle referenced in his lecture that repulsion strength goes in this order (LP-LP, LP-atom, atom-atom) thus the lone pairs will exert a bigger repulsive force on the other atoms making the other atoms get closer together (becomes less than 120 degrees or 109.5 what have you) so the LP can stay father apart.


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