Bond angle

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

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Alana Sur 3B
Posts: 61
Joined: Fri Sep 28, 2018 12:25 am

Bond angle

Postby Alana Sur 3B » Tue Nov 27, 2018 10:17 am

Do AX2E and AX2E2 have the same bond angles?

RachaelKoh3A
Posts: 33
Joined: Fri Sep 28, 2018 12:25 am

Re: Bond angle

Postby RachaelKoh3A » Tue Nov 27, 2018 10:18 am

i think AX2E has a bent shape with a bond angle that will be less than 120 degrees while AX2E2 also has a bent shape but with angles less than 109.5 degrees. This is on the basis that, AX2E comes from a trigonal planar shape with one corner of the triangle being a lone pair instead. Trigonal planar has 120 degree bond angles so if you replace one of the atoms in a trigonal plane with a lone pair of electrons, the lone pairs will push the other two bond closer together making it less than 120 degrees.

taryn_baldus2E
Posts: 62
Joined: Fri Sep 28, 2018 12:24 am

Re: Bond angle

Postby taryn_baldus2E » Tue Nov 27, 2018 10:37 am

No. Even though the two have the same molecular shape, the bond angle is also influenced by the lone pairs on the central atom since all regions of electron density play a role on the bond angles.

Matthew Mar 1J
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Joined: Fri Sep 28, 2018 12:15 am
Been upvoted: 1 time

Re: Bond angle

Postby Matthew Mar 1J » Tue Nov 27, 2018 11:27 am

Since AX2E has 3 regions of electron density, it's form comes from the trigonal planar shape and the angle will be slightly less than 120, but AX2E2 has 4 regions of electron density so it's form comes from a tetrahedral shape where two of the substituents are replaced with lone pairs. Coming from a tetrahedral shape, we already know the angle has to be less than 109.5, but the additional lone pair creates even greater repulsion so the angle will be even smaller in the end (take water for example which is AX2E2 with bond angle all the way down at 104.5 degrees).

905096106
Posts: 30
Joined: Fri Oct 05, 2018 12:17 am

Re: Bond angle

Postby 905096106 » Tue Nov 27, 2018 1:38 pm

No. Although both shapes have the same shape (bent) their bond angles are different because they have different electron geometry. AX2E has trigonal planar electron geometry while AX2E2 has tetrahedral electron geometry. Because of this AX2E has a bond angle of <120 while AX2E2 has a bond angle of <109.5

Alana Sur 3B
Posts: 61
Joined: Fri Sep 28, 2018 12:25 am

Re: Bond angle

Postby Alana Sur 3B » Fri Dec 07, 2018 10:26 pm

Thank you!!!


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