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Bond Angles

Posted: Fri Nov 09, 2018 11:40 am
by Shundeen Martinez 1D
What are bond angles and how can you predict them?

Re: Bond Angles

Posted: Fri Nov 09, 2018 11:47 am
by Hedi Zappacosta 1E
Bond angles are determined by the largest angle between to atoms in a molecule. It is dependent on how many bonds are in the molecule. For example, a molecule with two bonds coming off of the central atom will be linear, as a 180 degree angle is the largest possible angle between these two bonds.

Re: Bond Angles

Posted: Fri Nov 09, 2018 12:32 pm
by Linyu Zeng 1H
bond angles are the angles between two bondings in a atom (consider the bondings as lines and the central atom as the point). I think we can predicts them by putting atoms to achieve a most stable structure (basically by putting the atoms bound to the central one as far apart as possible), and calculate the angles (if we can).

Re: Bond Angles

Posted: Fri Nov 09, 2018 1:08 pm
by DavidEcheverri3J
What is the lowest degree that bonds can have in between each other? I know that electron repulsion leads to the largest possible degree of separation, but what could the lowest degree be?

Re: Bond Angles

Posted: Fri Nov 09, 2018 1:10 pm
by Lucy Agnew 3E
Bond angles are caused by the laws of electron repulsion theory, and atoms that interact around a central atom they are all bonded to orientate themselves to produce the most stable structure

Re: Bond Angles

Posted: Sat Nov 10, 2018 5:52 pm
by 204765696
To identify bond angles and shape, locate the central atom and see how many bonds are connected to it. You also have to count the lone pairs as bonds. If the number of bonds is 2, the shape is linear and angles are 180 degrees. If the number of bonds is 3, then the shape is triagonal planar and angles are 120 degrees. If the number of bonds is 4 then the shape is tetrahedral and angles are 109 degrees. etc etc

Re: Bond Angles

Posted: Sat Nov 10, 2018 6:47 pm
by Riya Shah 4H
Are we supposed to remember bond angles?

Re: Bond Angles

Posted: Tue Nov 20, 2018 8:03 pm
by Shundeen Martinez 1D
Also when can we know that bond angles are less than what they usually are? Like I remember in lecture Lavelle said a bond angle was 106.5 degrees.

Re: Bond Angles

Posted: Tue Nov 20, 2018 8:21 pm
by Kathryn 1F
Shundeen Martinez 1D wrote:Also when can we know that bond angles are less than what they usually are? Like I remember in lecture Lavelle said a bond angle was 106.5 degrees.


I think the one he was talking about was SO_3^2- (sulfite). By drawing the lewis structure, we see that the central atom, S, has 4 regions of electron density (1 lone pair and 3 bonds). This makes the shape trigonal pramidal. If it were tetrahedral, the bond angle would be 109.5, but because the lone pair wants to be as far away as possible, it pushes the 3 bonds away from it. This pushes the bonding pairs closer to each other, making the angle <109.5, or 106.

Re: Bond Angles

Posted: Wed Nov 21, 2018 2:17 pm
by Yukta Italia 3I
Yes I believe we are supposed to remember bond angles. I think the easiest thing to do is memorize them, but you can always try to visualize by drawing out the Lewis structure. That may get frustrating on a test with limited time though.

Re: Bond Angles

Posted: Thu Nov 22, 2018 12:20 am
by Brice McKeown 3D
Why is it that molecules with the same VESPR formula and lone pairs present have different bond angles? For example, look at the VESPR formula AX2E. O3 has bond angles of 116.8, but SO2 has bond angles of 119.5.

Re: Bond Angles

Posted: Thu Nov 22, 2018 1:20 am
by Arlene Linares 3A
Hedi Zappacosta 4H wrote:Bond angles are determined by the largest angle between to atoms in a molecule. It is dependent on how many bonds are in the molecule. For example, a molecule with two bonds coming off of the central atom will be linear, as a 180 degree angle is the largest possible angle between these two bonds.


Thank you and Can you give another example?

Re: Bond Angles

Posted: Thu Nov 22, 2018 1:21 am
by Arlene Linares 3A
Brice McKeown 3D wrote:Why is it that molecules with the same VESPR formula and lone pairs present have different bond angles? For example, look at the VESPR formula AX2E. O3 has bond angles of 116.8, but SO2 has bond angles of 119.5.


I see thank you.

Re: Bond Angles

Posted: Thu Nov 22, 2018 1:22 pm
by Jaifreen_Bhangu_3K
You could just memorize the angles. However, it's possible that we may have to explain why a certain bond angle is less than 109 degrees, etc.