## Stable Condition

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

TiffanyL1G
Posts: 61
Joined: Fri Sep 28, 2018 12:22 am

### Stable Condition

I am a bit confused about the stable condition and the equation used to calculate it. Is a molecule or atom the most stable when it's Lewis Structure is equal to zero or is it the most stable when it is equal to the charge? Like for [SO4]2-, is the molecule most stable when the Lewis Structure is equal to zero or minus two?

Also does a negative number just indicate a negative charge of x amount of electron? What about a positive number, does it mean the molecule or atom lost x amount of electrons?

Elisa Bass 4L
Posts: 61
Joined: Fri Sep 28, 2018 12:23 am

### Re: Stable Condition

I’m not sure if this is what you’re asking, but for the second part of your question, a molecule is negative when it has more electrons than it does positive charge from protons to even it out and positive when it has fewer electrons than it does protons as a whole.

TiffanyL1G
Posts: 61
Joined: Fri Sep 28, 2018 12:22 am

### Re: Stable Condition

Thanks for answering the second part! But for the first part I was confused on the example he gave for sulfate, (SO4)2-. I know that sulfate has a negative charge of 2 electrons, so I thought the most stable condition would be when the Formal Charge equals minus 2. Or is it when it equals 0? I remember Dr. Lavelle claiming the most stable state will be equal to zero, so I was wondering if the negative or positive charge of a molecule affects the formal charge?

Ray Guo 4C
Posts: 90
Joined: Fri Sep 28, 2018 12:15 am

### Re: Stable Condition

I think a molecule is the most stable when the formal charge of each atom, instead of the whole molecule, is zero. In SO4 we can't organize electrons in the way that every atom has a formal charge of 0, and the SO4 with a 2- charge is the most stable one we can get which has a structure with least formal charges on each atom.

Sophie Roberts 1E
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Joined: Fri Sep 28, 2018 12:17 am

### Re: Stable Condition

I believe molecules are always the most stable when the formal charge is equal to zero because that shows that the molecule is neutral.

Linh Vo 2J
Posts: 61
Joined: Sat Apr 28, 2018 3:00 am

### Re: Stable Condition

I believe that it is always desirable to make the formal charge of a compound ultimately zero because it shows that a molecule is neutral, if we can. However, with the example compound you gave [SO4]-2, it is not possible to make the formal charge zero, thus we would have to strive to make the formal charge equal to the 2- original charge.

Cameron_Greenberg_3C
Posts: 60
Joined: Fri Sep 28, 2018 12:26 am

### Re: Stable Condition

The charge of individual atoms that make up the ion should always be zero or as close to zero as possible. Atoms are most stable at that point and they always tend towards their lowest energy state. Even in an ion with 2- charge, the formal charge of each atom should be close to 0, not -2.

Karina Jiayu Xu 4E
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Joined: Fri Sep 28, 2018 12:29 am

### Re: Stable Condition

I might be wrong but I think Dr. Lavelle said that the molecule is the most stable when the FC is equal to 0

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

### Re: Stable Condition

905157345 wrote:I am a bit confused about the stable condition and the equation used to calculate it. Is a molecule or atom the most stable when it's Lewis Structure is equal to zero or is it the most stable when it is equal to the charge? Like for [SO4]2-, is the molecule most stable when the Lewis Structure is equal to zero or minus two?

Also does a negative number just indicate a negative charge of x amount of electron? What about a positive number, does it mean the molecule or atom lost x amount of electrons?

In the example you gave the center which is S will have 2 electrons on it and outside the brackets will just be a negative sign.