## Bond Angles

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

Chloe Thorpe 1J
Posts: 77
Joined: Fri Sep 28, 2018 12:16 am

### Bond Angles

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

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
Posts: 37
Joined: Fri Sep 28, 2018 12:29 am

### Re: Bond Angles

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
Posts: 30
Joined: Fri Sep 28, 2018 12:18 am

### Re: Bond Angles

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
Posts: 64
Joined: Fri Sep 28, 2018 12:24 am

### Re: Bond Angles

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
Posts: 34
Joined: Fri Sep 28, 2018 12:26 am

### Re: Bond Angles

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

Jaifreen_Bhangu_3K
Posts: 34
Joined: Fri Sep 28, 2018 12:26 am

### Re: Bond Angles

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

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

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
Posts: 33
Joined: Fri Sep 28, 2018 12:29 am
Been upvoted: 1 time

### Re: Bond Angles

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
Posts: 32
Joined: Tue Nov 21, 2017 3:01 am

### Re: Bond Angles

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

Andrew Lam 3B
Posts: 30
Joined: Fri Sep 28, 2018 12:24 am

### Re: Bond Angles

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

Grace Diaz 3F
Posts: 30
Joined: Fri Sep 28, 2018 12:24 am

### Re: Bond Angles

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

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
Posts: 67
Joined: Fri Sep 28, 2018 12:24 am

### Re: Bond Angles

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

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
Posts: 67
Joined: Tue Nov 14, 2017 3:01 am
Been upvoted: 1 time

### Re: Bond Angles

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