Formal Charge and stability [ENDORSED]

$FC=V-(L+\frac{S}{2})$

Rebecca Doan 2L
Posts: 51
Joined: Thu Jul 27, 2017 3:01 am

Formal Charge and stability

What is the relation between formal charge and stability of the structure?

sofiakavanaugh
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Re: Formal Charge and stability

This could be wrong, but I think that a formal charge of zero is the most stable, and the further away you get from zero the more unstable it is

Gurshaan Nagra 2F
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Joined: Thu Jul 27, 2017 3:01 am

Re: Formal Charge and stability

You want the formal charge on the elements to be as close to zero as possible. Since the formal charge can be negative or positive, the lower the absolute value of the formal charge, the higher the stability.

Aliza Ajmal 1D
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Joined: Fri Sep 29, 2017 7:05 am

Re: Formal Charge and stability

Another detail that might prove useful in assigning formal charge in lewis structures is that negative charge should be assigned to the more electronegative atom, and positive charge should be assigned to the less electronegative atom.

Sheel Shah 1H
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Joined: Fri Sep 29, 2017 7:04 am

Re: Formal Charge and stability

A really easy way to think about this concept of formal charge and stability is that you want to attain the lowest formal charge for a given lewis structure, because the one with the lowest formal charges is the most stable. In general, structures prefer to be as stable as possible, and you want to draw this configuration.

Also usually, the major component of resonance structures will be the most stable version of the lewis structure of that particular molecule.

Hope that helps! :)

Phillip Winters 2F
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Joined: Fri Sep 29, 2017 7:05 am

Re: Formal Charge and stability

Depending on the arrangement of single/double/triple bonds in a structure, there may be a difference in the formal charges of the atoms in the molecule, and the closer formal charges are to zero, the more stable the molecule is

Abigail Urbina 1K
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Joined: Thu Jul 27, 2017 3:01 am

Re: Formal Charge and stability  [ENDORSED]

You should aim to draw a Lewis structure with atoms with a formal charge as close to zero as possible. When you add all the formal charges of each of the atoms together, you get the overall formal charge of the compound itself. Lower formal charges correspond to more stability within those compounds. This is because resonance structures with have the lowest formal charge contribute the most to the Lewis structure for that compound.

Justin Lai 1C
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Joined: Fri Sep 29, 2017 7:04 am

Re: Formal Charge and stability

Also important to note that the most stable structures are those that have lower energy. Atoms form bonds in order to reach a state of lower energy which is why it takes energy to break bonds.