Structure Names

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

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Emily_Stenzler_2H
Posts: 196
Joined: Wed Sep 30, 2020 10:02 pm

Structure Names

Postby Emily_Stenzler_2H » Sun Dec 06, 2020 11:05 am

I'm guessing I missed this in lecture, but can someone explain why the octahedral structure is called octahedral when it has 6 bonds rather than 8? I am also a bit confused as to how the bipyramidal structures got their names- is it just because they have two 'points'?

If someone can explain the logic behind the structure names I would greatly appreciate it!

abby hyman
Posts: 93
Joined: Thu Jul 25, 2019 12:16 am

Re: Structure Names

Postby abby hyman » Sun Dec 06, 2020 11:13 am

The reason that a molecule with 6 electron regions has an octahedral geometry is that the shape that is made in which the atoms would be the most stable is called an octahedron. This shape has 6 vertices which would represent the positions of the 6 electron regions.
As for trigonal bipyramidal, a molecule with this shape would have 5 bound atoms and the way I think of it is that 3 atoms are arranged in a flat triangle and then the fourth and fifth atoms would be above and below the triangle which would form a top trigonal pyramid and a bottom trigonal pyramid.

Eliana Witham 2H
Posts: 101
Joined: Wed Sep 30, 2020 9:48 pm
Been upvoted: 2 times

Re: Structure Names

Postby Eliana Witham 2H » Sun Dec 06, 2020 11:24 am

For octahedral, when you create a shape out of the atoms, making each one a vertex, then you get an octahedron. This shape has 8 faces, hence the name. If you look up the shape online, it will make more sense!

Michael Cardenas 3B
Posts: 56
Joined: Wed Sep 30, 2020 9:34 pm

Re: Structure Names

Postby Michael Cardenas 3B » Sun Dec 06, 2020 10:00 pm

The reason that the shape of a molecule with 6 bonding regions is called octahedral is because the most stable shape for this molecule is an octahedron which has 8 faces.

Bai Rong Lin 2K
Posts: 91
Joined: Wed Sep 30, 2020 9:54 pm

Re: Structure Names

Postby Bai Rong Lin 2K » Sun Dec 06, 2020 10:18 pm

Emily_Stenzler_3H wrote:I'm guessing I missed this in lecture, but can someone explain why the octahedral structure is called octahedral when it has 6 bonds rather than 8? I am also a bit confused as to how the bipyramidal structures got their names- is it just because they have two 'points'?

If someone can explain the logic behind the structure names I would greatly appreciate it!

There is 6 bonding region which results in 8 faces hence the name!

Joshua Chung 2D
Posts: 96
Joined: Wed Sep 30, 2020 9:32 pm

Re: Structure Names

Postby Joshua Chung 2D » Sun Dec 06, 2020 10:48 pm

Octahedral structures are formed when 6 bonds orient regularly around a central atom, forming a structure with 8 faces (thus lending the name "octahedron"). I think of bipyramidal structures as two pyramids sharing a base, forming a shape similar to the green thing from Sims.


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