Sapling #3

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Shannon Moore 2L
Posts: 94
Joined: Wed Feb 26, 2020 12:17 am

Sapling #3

Postby Shannon Moore 2L » Sun Nov 08, 2020 12:07 pm

I am still struggling to understand how to draw Lewis structures that "minimize formal charge." What is the best way to approach these types of problems?

MichaelRaad_1F
Posts: 90
Joined: Wed Sep 30, 2020 9:35 pm

Re: Sapling #3

Postby MichaelRaad_1F » Sun Nov 08, 2020 12:13 pm

I calculate the formal charge of each element in a bond and try to get the charge to be as close to 0 as possible using the formula Valence electrons-(lone pairs+ shared electrons/2).

Isis_DW_3G
Posts: 103
Joined: Wed Sep 30, 2020 10:04 pm

Re: Sapling #3

Postby Isis_DW_3G » Sun Nov 08, 2020 1:09 pm

Hi Shannon!
Personally, I draw out the lewis structure first with just single bonds, then calculate formal charge using the forumla Valence E-(shared/2 +Lone E-). If I find that there is a formal charge higher than 0, I then start to add double bonds if necessary. It's kind of like a guess and check type of thing. Formal charge will always be your best indicator!
Hope this helps!

AlyssaMaynard1C
Posts: 90
Joined: Fri Mar 06, 2020 12:15 am

Re: Sapling #3

Postby AlyssaMaynard1C » Sun Nov 08, 2020 1:18 pm

Shannon Moore 2L wrote:I am still struggling to understand how to draw Lewis structures that "minimize formal charge." What is the best way to approach these types of problems?

I'm having similar struggles and also assigning the formal charge is challenging for me on sapling. Does anyone know how to assign the formal charge with the sapling tools?

Rylee Mangan 1K
Posts: 92
Joined: Wed Sep 30, 2020 9:40 pm
Been upvoted: 2 times

Re: Sapling #3

Postby Rylee Mangan 1K » Sun Nov 08, 2020 1:49 pm

The best way to understand and easily draw Lewis Structures is by practicing a ton! Through practice, you will understand how many bonds each element usually likes and be able to draw the least charged molecule. Understanding that N likes 3 bonds, O likes 2 bonds, Carbon likes 4, and Hydrogen likes 1, and halogens usually only like one, you can more easily determine how to draw structures with the lowest/zero formal charge.

Danielle DIS2L
Posts: 92
Joined: Wed Sep 30, 2020 9:38 pm

Re: Sapling #3

Postby Danielle DIS2L » Sun Nov 08, 2020 4:19 pm

This is how I do it

I draw the lewis structures with single bonds first and calculate the formal charge. If there are any formal charge that is higher than 0, that's when I add double bonds.

Jaclyn Schwartz 1I
Posts: 101
Joined: Wed Sep 30, 2020 9:45 pm

Re: Sapling #3

Postby Jaclyn Schwartz 1I » Sun Nov 08, 2020 7:04 pm

For the most part its guess and check work which can get tedious, but just use the formula charge equation to help if you need. The more you do the better you will get at them so don't worry! You got it.

Ariana Flores 3F
Posts: 48
Joined: Thu Sep 19, 2019 12:16 am

Re: Sapling #3

Postby Ariana Flores 3F » Sun Nov 08, 2020 7:17 pm

If you haven't seen the video called Bonding Models and Lewis Structures: Crash Course Chemistry #24 by Crash Course on YouTube, you should check it out! It helped me a lot!

https://www.youtube.com/watch?v=a8LF7JEb0IA

Yeprem
Posts: 82
Joined: Wed Sep 30, 2020 9:40 pm

Re: Sapling #3

Postby Yeprem » Sun Nov 08, 2020 9:39 pm

Honestly, I would say start with the minimum (single bonds) and then if necessary just guess and check till you get the lowest possible formal charge for all your elements. I do not think there is a shortcut for this.

nayha a 1E
Posts: 96
Joined: Wed Sep 30, 2020 9:54 pm

Re: Sapling #3

Postby nayha a 1E » Sun Nov 08, 2020 9:43 pm

AlyssaMaynard1C wrote:
Shannon Moore 2L wrote:I am still struggling to understand how to draw Lewis structures that "minimize formal charge." What is the best way to approach these types of problems?

I'm having similar struggles and also assigning the formal charge is challenging for me on sapling. Does anyone know how to assign the formal charge with the sapling tools?

To assign the formal charge on Sapling, select More and there will be + and - buttons. You also click on the one you want this charge to be added to. Also, the more times you click + or -, the more it will add. For example, click - twice to get 2-.

Adrienne Chan 1G
Posts: 94
Joined: Wed Sep 30, 2020 9:40 pm

Re: Sapling #3

Postby Adrienne Chan 1G » Sun Nov 08, 2020 10:01 pm

So what helped me the most was drawing different structures and calculating the formal charges for each atom in each configuration. It takes me a little while to do it but it's the most reliable way I've found!


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