linear same atoms?

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

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Kayko Lee 1C
Posts: 111
Joined: Wed Sep 30, 2020 9:39 pm

linear same atoms?

Postby Kayko Lee 1C » Fri Dec 04, 2020 8:41 pm

I just want to confirm that if for example you had to find the molecular geometry for I3- it would be linear because they're all iodines? I got 3 lone pairs for that and thought it would be bent but it was linear instead

Alvin Lai 3J
Posts: 90
Joined: Wed Sep 30, 2020 9:55 pm

Re: linear same atoms?

Postby Alvin Lai 3J » Fri Dec 04, 2020 8:53 pm

Hey! So you are right in that there are three lone pairs on the middle Iodine. This makes five electron densities, and that would be trigonal bipyramidal. The three lone pairs take all the equatorial electron densities, leaving only the axial atoms as Iodine. This makes the linear shape. Hope this helps!

Olivia Smith 2E
Posts: 87
Joined: Wed Sep 30, 2020 9:43 pm

Re: linear same atoms?

Postby Olivia Smith 2E » Sat Dec 05, 2020 2:18 pm

The fact that they are all of the same element does not matter at all. You have to take into account all of the lone pairs and bonded pairs to get the shape!

Ethan Laureano 3H
Posts: 87
Joined: Wed Sep 30, 2020 9:58 pm

Re: linear same atoms?

Postby Ethan Laureano 3H » Sat Dec 05, 2020 4:46 pm

My preferred method would be to determine the number of electron densities around the central atom and then figure out which ones are bonding pairs and which ones are lone pairs. This requires some memorization or visualization skills. For example, like someone mentioned before, this molecule has five electron densities around the central atom. From there, you can substitute three bonding pairs for lone pairs. You can either memorize that AX2E3 is linear or you can visualize that the three lone pairs occupy the equatorial atoms making the remaining atoms axial (linear).

Matlynn Giles 2E
Posts: 88
Joined: Wed Sep 30, 2020 10:10 pm
Been upvoted: 1 time

Re: linear same atoms?

Postby Matlynn Giles 2E » Sat Dec 05, 2020 5:20 pm

Just because something is the same element does not mean they're the same! He talks about this in his lecture about chemothearpy. I believe it was Monday's lecture of week 9.

Adam Bustamante 1I
Posts: 93
Joined: Wed Sep 30, 2020 9:51 pm

Re: linear same atoms?

Postby Adam Bustamante 1I » Sun Dec 06, 2020 10:44 am

You have to take into consideration the amount of lone pairs on the structure, as they can modify the shape and push down on the other bonds, lessening the bond angles.It doesn't matter if the lewis structure is all the same element, it's all about lone pairs and regions of electron density.

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

Re: linear same atoms?

Postby abby hyman » Sun Dec 06, 2020 11:15 am

I believe the fact that they are the same atom does not make a difference in this case. You have to take into account the bound atoms and lone pairs to determine the geometry


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