Page 1 of 1

### Formula for determining bond angle

Posted: Thu Nov 15, 2018 9:07 pm
Is there a universal formula for determining the bond angles of any molecule? If so, is this something we must know for test three?

### Re: Formula for determining bond angle

Posted: Thu Nov 15, 2018 9:46 pm
There is no "formula," but each type of shape has their own specific bond angles that you'll have to picture in your head and/or memorize. For example, a tetrahedral shape has bond angles of 109.5, and that's a number you should remember.

### Re: Formula for determining bond angle

Posted: Thu Nov 15, 2018 10:31 pm
It mostly depends on how many electron density areas there are in a shape and in order to give the angle, I would memorize them.

### Re: Formula for determining bond angle

Posted: Fri Nov 16, 2018 12:13 am
We can estimate bond angles based on the molecule's VSEPR shape, however, only experimentally testing for bond angle gives us the actual bond angle between atoms in a molecule.

### Re: Formula for determining bond angle

Posted: Sat Nov 17, 2018 3:32 pm
There isn't really a formula, I would just know the values of the main shapes. For example, know that trigonal planar is 120, tetrahedral is 109.5, and if there is a lone pair instead of a bond (such as in trigonal pyramidal), it would be slightly less than 109.5.

### Re: Formula for determining bond angle

Posted: Sat Nov 17, 2018 5:04 pm
Is it possible to tell which molecules have smaller bond angles even when we're not sure exactly what the bond angles are? Like would the size of the atoms in the molecule have an effect on the bond angles, or is it just a matter of how many / what kind of electron pairs there are?

### Re: Formula for determining bond angle

Posted: Sat Nov 17, 2018 5:46 pm
There is no formula for determining bond angle. A lot of the times we can only know the approximate bond angles because it differ based on the electron pair repulsion.