Bond Angles

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

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Chloe Thorpe 1J
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Joined: Fri Sep 28, 2018 12:16 am

Bond Angles

Postby Chloe Thorpe 1J » Sat Nov 17, 2018 6:40 pm

Are we supposed to memorize bond angles for different shapes? Or is there a way to calculate them? Just wondering in case it comes up on an exam.

Charles Gu 1D
Posts: 60
Joined: Fri Sep 28, 2018 12:16 am

Re: Bond Angles

Postby Charles Gu 1D » Sat Nov 17, 2018 6:46 pm

You just need to memorize them. There are a lot of good practice problems that help you memorize the angles in the book.

Mariam Baghdasaryan 4F
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Joined: Fri Sep 28, 2018 12:29 am

Re: Bond Angles

Postby Mariam Baghdasaryan 4F » Sat Nov 17, 2018 6:52 pm

I believe that Professor Lavelle said we don't need to know the exact bond angles for specific molecules, but we should know it for the general shape. So if you identify a molecule to have the trigonal pyramidal shape (3 bonding pairs and 1 lone pair), you can say that the bond angles for that molecule are slightly less than 109.5 since a tetrahedral (4 bonding pairs) has bond angles of 109.5.

Jeremy Feng 1A
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Joined: Fri Sep 28, 2018 12:18 am

Re: Bond Angles

Postby Jeremy Feng 1A » Sat Nov 17, 2018 7:21 pm

The questions will likely ask us to estimate the bond angles, in which case we would take into account the positioning of the lone pair electrons. Depending on where the lone pair electrons are, we can estimate if the bond angle is greater than or less than the standard shape's angle.

Catly Do 2E
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Joined: Fri Sep 28, 2018 12:24 am

Re: Bond Angles

Postby Catly Do 2E » Sat Nov 17, 2018 8:30 pm

It isn't necessary to memorize exact bond angles for specific molecules. Dr. Lavelle mentioned that we just need to know how lone pairs affect repulsion and nearby bond angles (i.e. a lone pair will push against adjacent bond angles, making them less than the standard degree for that specific shape).

Jaifreen_Bhangu_3K
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Joined: Fri Sep 28, 2018 12:26 am

Re: Bond Angles

Postby Jaifreen_Bhangu_3K » Sat Nov 17, 2018 9:38 pm

You should know the general bond angle, but you don't need to know the exact bond angle.

Jaifreen_Bhangu_3K
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Joined: Fri Sep 28, 2018 12:26 am

Re: Bond Angles

Postby Jaifreen_Bhangu_3K » Sat Nov 17, 2018 9:39 pm

You should know the general bond angle, but you don't need to know the exact bond angle.

MinaChoi_3H
Posts: 31
Joined: Fri Sep 28, 2018 12:25 am

Re: Bond Angles

Postby MinaChoi_3H » Sat Nov 17, 2018 11:46 pm

You'll need to memorize the angles, but not how to draw them.

Jennifer Lathrop 1F
Posts: 71
Joined: Sat Dec 02, 2017 3:00 am

Re: Bond Angles

Postby Jennifer Lathrop 1F » Sun Nov 18, 2018 12:05 am

For this, is there a way to calculate or memorize bond angles when there is a lone pair? It is usually slightly different than the angles of the normal structure. Is there a set degree amount that a lone pair shifts a bond?

Sydni Stewart
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Re: Bond Angles

Postby Sydni Stewart » Sun Nov 18, 2018 10:57 am

Jennifer Lathrop 3E wrote:For this, is there a way to calculate or memorize bond angles when there is a lone pair? It is usually slightly different than the angles of the normal structure. Is there a set degree amount that a lone pair shifts a bond?

There's no set amount of change I believe. I just know that the more lone pairs there are, the stronger the repulsion away from them and therefore the smaller the angle gets. There is a chart with the exact angles if you's like to memorize them!

Karla_Ocampo 4E
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Joined: Tue Nov 21, 2017 3:01 am

Re: Bond Angles

Postby Karla_Ocampo 4E » Sun Nov 18, 2018 11:05 am

I think its best to just memorize them to be safe.

Andrew Lam 3B
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Joined: Fri Sep 28, 2018 12:24 am

Re: Bond Angles

Postby Andrew Lam 3B » Sun Nov 18, 2018 11:18 am

It would probably be safe to know the most common ones just in case they come up on a test.

Grace Diaz 3F
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Joined: Fri Sep 28, 2018 12:24 am

Re: Bond Angles

Postby Grace Diaz 3F » Sun Nov 18, 2018 1:04 pm

I think it would be helpful to memorize the bond angles respective to the molecular shape.

George Ghaly 2L
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Re: Bond Angles

Postby George Ghaly 2L » Sun Nov 18, 2018 1:43 pm

Each molecular shape has its own respective bond angles, the easiest way to figure out these angles is just by memorizing them.

Aiden Atoori 1C
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Joined: Fri Sep 28, 2018 12:24 am

Re: Bond Angles

Postby Aiden Atoori 1C » Sun Nov 18, 2018 1:52 pm

You should generally be familiar with bond angles but i do not think I️t is completely necessary to memorize them!

Manas Jinka
Posts: 32
Joined: Fri Sep 28, 2018 12:26 am

Re: Bond Angles

Postby Manas Jinka » Sun Nov 18, 2018 2:48 pm

In regards to bond angles affected by electron electron repulsion, we don't need to know the exact angles of those angles. Just know that repulsion reduces bond angles.

KarlaArevalo2F
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Re: Bond Angles

Postby KarlaArevalo2F » Sun Nov 18, 2018 2:51 pm

I believe he mentioned we should know the general ones like 90, 180, and for bent it should be slightly less than 109.5 but not the exact angle


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