## Formal Charge Question

Bita Ghanei 1F
Posts: 60
Joined: Thu Feb 28, 2019 12:15 am

### Formal Charge Question

In order for two resonance structures to be valid, do they have to have the same formal charges on all their atoms? Or do they have to sum up to have the same overall charge?

Montana James 4G
Posts: 46
Joined: Wed Sep 18, 2019 12:21 am

### Re: Formal Charge Question

They just have to sum up to the same overall charge, as far as I know. Not sure if this is what you mean, but some resonant structures are more stable than others due to the formal charges of all the atoms being lower (i.e, all of them being 0 or +1 versus one atom being +2 and others being 0)

Cynthia Gong 1L
Posts: 51
Joined: Fri Aug 09, 2019 12:15 am

### Re: Formal Charge Question

The most stable and ideal resonance structure would have a formal charge of 0 on each individual atom. However, that may not happen if the molecule is charged. If we have something such as SO4(2-), then the individual formal charges on each individual atom should add up to a total of -2. If a resonance structure's charge adds up correctly, it is valid, but the most ideal structure would have formal charges of 0 on each atom or on at least the central atom.

Caitlyn Tran 2E
Posts: 100
Joined: Fri Aug 09, 2019 12:15 am

### Re: Formal Charge Question

I believe that the textbook said a resonance structure is any structure in which the atoms are in the same place, but the bonds or location of electrons can move around. In this sense, resonance structures do not all have to be the lowest charge, but I think if we were asked about resonance structures on a test, we are only expected to put the most stable ones. Hope this helps!

emma brinton_3B
Posts: 53
Joined: Fri Aug 09, 2019 12:17 am

### Re: Formal Charge Question

no the resonance structures do not need to have the same formal charge for all the atoms. The only thing that must stay the same is the overall charge. the difference in formal charge is what causes one molecule structure to be more stable or favorable than others.

vanessas0123
Posts: 100
Joined: Wed Sep 11, 2019 12:17 am

### Re: Formal Charge Question

Sum up to the overall charge!

Astrid Lunde 1I
Posts: 103
Joined: Sat Sep 07, 2019 12:16 am

### Re: Formal Charge Question

They have to add up to the same formal charge.

Ellen Amico 2L
Posts: 101
Joined: Thu Sep 19, 2019 12:16 am

### Re: Formal Charge Question

They should just sum up to the overall charge! For example if your structure is an ion that has a charge of -2, the formal charges should add up to that. But the formal charges on the atom for each resonance structure will vary because the bonds vary.

AmyL_3L
Posts: 50
Joined: Fri Aug 09, 2019 12:17 am

### Re: Formal Charge Question

The formal charges of all the atoms in a resonance structure should sum up to have the same overall charge as the other resonance structure. The formal charge of an atom can vary.

Ying Yan 1F
Posts: 101
Joined: Fri Aug 02, 2019 12:16 am

### Re: Formal Charge Question

For all molecular structures the atoms should have a formal charge where the molecule equal zero or equal to the charged the molecule is assigned. I hope that helps!

SVajragiri_1C
Posts: 115
Joined: Thu Jul 11, 2019 12:16 am

### Re: Formal Charge Question

The only requirement is for the sum of the formal charges to add up to the overall charge.

Veronica Lu 2H
Posts: 89
Joined: Wed Sep 18, 2019 12:18 am
Been upvoted: 1 time

### Re: Formal Charge Question

they need to all add up and equal the overall charge

jvera4b
Posts: 60
Joined: Wed Sep 11, 2019 12:17 am

### Re: Formal Charge Question

They have to sum up to the overall formal charge. Each atom's formal charge may vary but they all have to add up to the same overall charge.

Jacob Villar 2C
Posts: 105
Joined: Sat Aug 17, 2019 12:18 am

### Re: Formal Charge Question

The total formal charge should be equal between resonance structures, although the charges of the individual atoms may differ.

Posts: 52
Joined: Thu Jul 11, 2019 12:16 am

### Re: Formal Charge Question

The formal charge of a resonance structure should be equal to the atom's overall charge.

Jacob Villar 2C
Posts: 105
Joined: Sat Aug 17, 2019 12:18 am

### Re: Formal Charge Question

Yeah the resonance structures should amount to the same overall charge.