Which Diagram to draw in a bond with both elements Z<8 and Z>8  [ENDORSED]

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Raul Hernandez
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Which Diagram to draw in a bond with both elements Z<8 and Z>8

Postby Raul Hernandez » Tue Nov 01, 2016 11:40 pm

I hope this is not trivial, but I was wondering what diagram do you choose to draw when you have two elements that are: one less than 8 protons and another with more than 8 protons. For example, how would you draw the Molecular Diagram for Fluorine and Carbon together (CF) and why? Any help will be appreciated.

Brian Devlin 3B
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Re: Which Diagram to draw in a bond with both elements Z<8 and Z>8

Postby Brian Devlin 3B » Wed Nov 02, 2016 1:20 am

I'm not quite sure if molecular diagrams will be tested on this midterm...someone tell me if they are but I don't think so.

aprilhamachi3B
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Re: Which Diagram to draw in a bond with both elements Z<8 and Z>8

Postby aprilhamachi3B » Wed Nov 02, 2016 3:48 am

I don't know if you mean a bond between an atom with close to eight electrons and an atom with far fewer. I don't see a molecule like CF existing because if it bonded their would be 3 unbonded electrons left on the carbon. otherwise when you're focusing on drawing the lewis structures just pay attention to the valence electrons and the amount of unpaired electrons

Amy Ko 3C
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Re: Which Diagram to draw in a bond with both elements Z<8 and Z>8

Postby Amy Ko 3C » Wed Nov 02, 2016 9:05 am

For heteronuclear diatomic molecules (one element has Z<8 and other has Z>8), see the BO molecule example provided by this page:http://www.nyu.edu/classes/tuckerman/adv.chem/lectures/lecture_15/node1.html
The energy level of orbitals of element Z>8 will be lower than those of element Z<8 and pi 2px and pi 2py are lower in energy than sigma 2pz (which is the MO for Z<8)
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Raul Hernandez
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Re: Which Diagram to draw in a bond with both elements Z<8 and Z>8

Postby Raul Hernandez » Wed Nov 02, 2016 10:26 am

It was an example on the 2013 Fall Midterm, and it is a heteronuclear molecule. My question was whether to use the diagram provided for the elements with z<8 or z>8 (both are similar but they differ in the placement of the sigma pz bonds). However, I think that the example given by Amy Ko (Thank you, by the way) helps with my confusion. Thanks to everyone for the help, though.

Chem_Mod
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Re: Which Diagram to draw in a bond with both elements Z<8 and Z>8  [ENDORSED]

Postby Chem_Mod » Wed Nov 02, 2016 10:54 am

I discussed this in detail in Monday's class and went through CO as an example.
I also discussed why the more electronegative atom has lower energy atomic orbitals.

For heteronuclear diatomic molecules with one Z > 8 and the other Z < 8 use the diagram for Z < 8.
The above diagram also shows this. Oxygen would be on the right side of this diagram.

[PS. Students who don't come to class miss a lot of material, announcements, etc.
Some students are only finding out today that "both the midterm and final will include one homework question". Yet I announced this several times and it is explicitly written in the quiz and exam schedule.]

Jaime_Chamberlain_3G
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Re: Which Diagram to draw in a bond with both elements Z<8 and Z>8

Postby Jaime_Chamberlain_3G » Sun Nov 06, 2016 10:22 pm

Can you please give a basic outline of how to draw the diagram? I'm still slightly confused on how to get started. Thank you.

Alexandria_Leaf_2F
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Re: Which Diagram to draw in a bond with both elements Z<8 and Z>8

Postby Alexandria_Leaf_2F » Mon Nov 07, 2016 9:47 am

Are those dotted lines necessary to draw between the atomic orbitals and the molecular orbitals? Or can we leave them out?

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Re: Which Diagram to draw in a bond with both elements Z<8 and Z>8

Postby Chem_Mod » Mon Nov 07, 2016 2:10 pm

The dotted lines can be left out.


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