Charges on Lewis Structures

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Kellylin_4D
Posts: 66
Joined: Sat Aug 24, 2019 12:17 am

Charges on Lewis Structures

Postby Kellylin_4D » Wed Oct 30, 2019 1:05 pm

if a compound is negatively charged, where do we put this extra electron?

sarahwu3a
Posts: 50
Joined: Sat Aug 17, 2019 12:17 am

Re: Charges on Lewis Structures

Postby sarahwu3a » Wed Oct 30, 2019 4:18 pm

If the compound is negatively charged the electrons should indicate so, the only thing you have to add are a minus sign and brackets around the molecule.

Izzie Capra 2E
Posts: 103
Joined: Sat Sep 07, 2019 12:19 am

Re: Charges on Lewis Structures

Postby Izzie Capra 2E » Wed Oct 30, 2019 6:07 pm

I would be sure to check and make sure you have the correct number of valence electrons when you draw the structure. If not already indicated, you also have to account for the electron that is gained. You will most likely place that electron around the central atom. Then, you can place the brackets and negative charge around the molecule.

Ruth Glauber 1C
Posts: 100
Joined: Wed Sep 18, 2019 12:20 am

Re: Charges on Lewis Structures

Postby Ruth Glauber 1C » Thu Oct 31, 2019 11:23 am

I think you should only have to make the positive or negative notation on the atom itself (eg. Na+).

Jorge Ramirez_4H
Posts: 54
Joined: Wed Nov 21, 2018 12:19 am

Re: Charges on Lewis Structures

Postby Jorge Ramirez_4H » Thu Oct 31, 2019 2:43 pm

For example is we had Br03- and we were adding up the electrons why would we add one instead of subtract one?

MinuChoi
Posts: 100
Joined: Wed Sep 18, 2019 12:15 am

Re: Charges on Lewis Structures

Postby MinuChoi » Thu Oct 31, 2019 2:49 pm

For example is we had Br03- and we were adding up the electrons why would we add one instead of subtract one?

A charge of -1 means that the compound has 1 extra electron (more electrons than protons means a negative charge). The Lewis structure would show an amount of electrons equal to the total of the atoms' valence electrons plus one.

For BrO3-, that would be 7+6+6+6+1=26 valence electrons.

Anvi Brahmbhatt 4A
Posts: 51
Joined: Wed Sep 18, 2019 12:21 am

Re: Charges on Lewis Structures

Postby Anvi Brahmbhatt 4A » Thu Oct 31, 2019 3:17 pm

Add the electron when counting how many valence electrons are present in the compound. Add the brackets and the negative sign around the structure after you have drawn it.

ABombino_2J
Posts: 102
Joined: Thu Jul 11, 2019 12:15 am

Re: Charges on Lewis Structures

Postby ABombino_2J » Fri Nov 01, 2019 12:44 pm

For a molecule with a +1 charge such as ammonium, NH4+, you would subtract one e- from the valence e- so the total valence e- would 8. For a molecule with a -1 share like sulfate, SO4^2-, you would add 2 extra valence e-. The result is 32. To draw the lewis structure, just be sure to satisfy the amount of valence electrons and try to keep formal charge as close to 0 as possible.


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