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Bond Angles

Posted: Sat Nov 17, 2018 9:42 pm
by taiyeojeikere-3C
Can you only determine bond angles by drawing the molecular shape of that molecule?

Re: Bond Angles

Posted: Sat Nov 17, 2018 9:56 pm
by Andie Jian 1D
I'm not completely sure, but I do think you would need to know the VSEPR shape in order to figure out the bond angles, because that takes into account the electron repulsions that create those angles.

Re: Bond Angles

Posted: Sat Nov 17, 2018 10:12 pm
by Kevin ODonnell 2B
Something to keep in mind as well is when lone pairs are involved it changes the bond angle from the expected amount. For example NH3 has bond angles of 107 degrees instead of the expected 109.5 degrees. There is no way to know this since it needs to be tested in the lab since it's unique to each molecule so we represent the cases with lone pairs as saying that the bond angle is less than 109.5 degrees.

Re: Bond Angles

Posted: Sun Nov 18, 2018 12:06 am
by Jennifer Lathrop 1F
is there a set degree that a lone pair shifts the surrounding bonds around it? Or does this just come from experiments?

Re: Bond Angles

Posted: Sun Nov 18, 2018 2:45 pm
by Manas Jinka
It's important to know that more electron electron repulsions lead to reduced bond angles.

Re: Bond Angles

Posted: Sun Nov 18, 2018 2:57 pm
by Jaqueline Monreal 2L
im not sure but i think its the most effective and reliable way to figure it out, maybe you can use the VSEPR formula to figure it out

Re: Bond Angles

Posted: Sun Nov 18, 2018 6:58 pm
by Daniel Chang 3I
Drawing out the shape of the molecule helps to see where each bond is located and therefore where each bond angle would be. It would be a lot harder to determine bond angles without actually drawing out the shape through VSEPR

Re: Bond Angles

Posted: Sun Nov 18, 2018 7:02 pm
by Tony Chung 2I
Drawing the structure is highly recommended when determining the bond angle.

Re: Bond Angles

Posted: Sun Nov 18, 2018 10:49 pm
by 905096106
Drawing out the shape or simply determining the shape through visualization is the best way to determine the shape.

Re: Bond Angles

Posted: Sun Nov 18, 2018 10:54 pm
by Sheridan Slaterbeck 1J
If you know the VSEPR model , you should be able to remember the bond angle associated with it like 120, or 109.5, or 90 degrees. Then figure out how the lone pairs push on the bonding pairs and affect the angles ( I find this is easiest by drawing it).

Re: Bond Angles

Posted: Sun Nov 18, 2018 11:01 pm
by 404536963
I assume that for the next exam/final, we will only be asked to determine the bond angles when also asked to draw the Lewis Structure for partial points. So, you'd draw the dot structure then determine the VSEPR shape and corresponding bond angles. Finding the dot structure is really important because it tells you the written shape of the molecule/ which atoms are connected + lone pairs, so I would suggest practicing that so it makes the process faster.

Re: Bond Angles

Posted: Sun Nov 18, 2018 11:12 pm
by marg44
I'm not sure if it's the only way but it is the only way Lavelle has taught us in class.

Re: Bond Angles

Posted: Sun Nov 18, 2018 11:42 pm
by 405098546
Drawing Lewis structures is very helpful, because it helps you avoid making careless mistakes.