Formal Charge


Moderators: Chem_Mod, Chem_Admin

Dustin Shin 2I
Posts: 64
Joined: Fri Sep 28, 2018 12:26 am

Formal Charge

Postby Dustin Shin 2I » Sun Nov 11, 2018 10:12 pm

When we need to draw Lewis structures or even resonance structures, do we need to show calculations done for formal charges in order not to miss points on exams? Will that ever be an issue? The last test asked to show full work so I am wondering if this is necessary.

WilliamNguyen_4L
Posts: 65
Joined: Fri Sep 28, 2018 12:28 am

Re: Formal Charge

Postby WilliamNguyen_4L » Sun Nov 11, 2018 10:15 pm

Last test I just drew the most stable form of the lewis structure. I wrote all the calculations. If they ask for resonance then I think you should draw the resonance structures.

Sheridan Slaterbeck 1J
Posts: 62
Joined: Fri Sep 28, 2018 12:27 am

Re: Formal Charge

Postby Sheridan Slaterbeck 1J » Sun Nov 11, 2018 10:19 pm

I think you should always show your calculations for formal charge, each TA grades differently but my TA said the more work you show the greater chance you will earn more points.

Luc Lorain 1L
Posts: 59
Joined: Fri Sep 28, 2018 12:18 am

Re: Formal Charge

Postby Luc Lorain 1L » Sun Nov 11, 2018 10:20 pm

For Lewis structures with equivalent resonance structures, I did the calculations for one of the structures, and put the appropriate formal charges around the other resonance forms. Otherwise, yeah you should do independent calculations for each resonance form.

Diana Sandoval 1K
Posts: 61
Joined: Fri Sep 28, 2018 12:25 am
Been upvoted: 1 time

Re: Formal Charge

Postby Diana Sandoval 1K » Mon Nov 12, 2018 1:22 pm

WilliamNguyen_4D wrote:Last test I just drew the most stable form of the lewis structure. I wrote all the calculations. If they ask for resonance then I think you should draw the resonance structures.

What's the difference between the Lewis structure and the resonance structure?

AlyssaBei_1F
Posts: 99
Joined: Fri Sep 28, 2018 12:17 am

Re: Formal Charge

Postby AlyssaBei_1F » Mon Nov 12, 2018 1:29 pm

A resonance is a Lewis structure that have bonds in different equivalent locations.

Aleeque Marselian 1A
Posts: 60
Joined: Fri Sep 28, 2018 12:24 am

Re: Formal Charge

Postby Aleeque Marselian 1A » Mon Nov 12, 2018 2:33 pm

In my opinion, it is always better to show work just in case. Especially if the grader prefers to see the steps.

katie_sutton1B
Posts: 61
Joined: Fri Sep 28, 2018 12:17 am

Re: Formal Charge

Postby katie_sutton1B » Mon Nov 12, 2018 2:35 pm

It's obviously better if you do because of partial credit, but it's not necessary.

Arlene Linares 3A
Posts: 50
Joined: Fri Sep 28, 2018 12:25 am

Re: Formal Charge

Postby Arlene Linares 3A » Tue Nov 13, 2018 2:48 pm

How many points was the FC worth on the midterm?

uhedlund
Posts: 38
Joined: Wed Nov 15, 2017 3:03 am

Re: Formal Charge

Postby uhedlund » Sun Dec 09, 2018 11:24 pm

It is always better to show work just in case, but generally for formal charge I do not think it is necessary

205458163
Posts: 33
Joined: Wed Jun 26, 2019 12:15 am

Re: Formal Charge

Postby 205458163 » Fri Jul 12, 2019 8:26 pm

In my opinion, the answer is yes, you should draw a figure of the structure. And you also should calculate the formal charge and show the calculation steps.

simmoneokamoto1B
Posts: 17
Joined: Mon Jun 17, 2019 7:22 am

Re: Formal Charge

Postby simmoneokamoto1B » Sun Jul 14, 2019 7:02 pm

I wouldn't say you need to show all your work, but I definitely recommend it, in the worst case hypothetical you get the question wrong, you can, at the very least, get partial credit for showing your work.

Sisi Li 1F
Posts: 34
Joined: Mon Mar 11, 2019 12:15 am

Re: Formal Charge

Postby Sisi Li 1F » Sun Jul 14, 2019 10:32 pm

I'd say you should show your formal charge calculations, just to show that you know a certain lewis structure is correct. Could depend on the TA though.


Return to “Formal Charge and Oxidation Numbers”

Who is online

Users browsing this forum: No registered users and 1 guest