## Bond Angles

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

Clarissa Cabil 1I
Posts: 66
Joined: Fri Sep 28, 2018 12:19 am

### Bond Angles

When doing the homework, the solutions manual sometimes mentions how certain bond angles are "slight less than" 109.5º or 120º etc., but how can you tell if a certain shape is exactly, approximately, or slightly less than a certain degree?

Rachel Yoo 1F
Posts: 65
Joined: Fri Sep 28, 2018 12:24 am

### Re: Bond Angles

I think bond angles is something you just need to memorize by VSEPR

Becky Belisle 1A
Posts: 81
Joined: Fri Sep 28, 2018 12:18 am

### Re: Bond Angles

I think slightly less than has to do with lone pairs affecting what the angle normally is for a certain structure.

Shibhon_Shepard
Posts: 62
Joined: Wed Nov 15, 2017 3:04 am

### Re: Bond Angles

If you do draw them out, I would recommend explicitly writing the degrees somewhere just to be safe. This will also show your TA that you know what bond angle is actually there without having to actually draw out a 109.5 degrees vs a 120 degree angle.

Grace Kim 1J
Posts: 60
Joined: Fri Sep 28, 2018 12:18 am
Been upvoted: 1 time

### Re: Bond Angles

https://www.angelo.edu/faculty/kboudrea/index/Handout_Lewis_VSEPR.pdf

I had the same question at first, but I used resources online (like the link above) to help me know the bond angles. I think as you do more problems, you start to familiarize yourself with the different angles according to their molecular shape and eventually memorize them!

Veronica Soliman 4H
Posts: 51
Joined: Fri Sep 28, 2018 12:28 am

### Re: Bond Angles

We did a demo in class where if it’s 4 bonds, you just recall it’s a 3d shape so while you would think it is 90 degrees, it’s actually 109 because it’s 3dinensional. The first 3 are pretty self explanatory so 2 bonds would likely be farther apart and are at 180 degrees.