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Formal Charges on Atoms Summed in Ions?

Posted: Tue Oct 29, 2019 3:57 pm
by Bita Ghanei 1F
If you have an ion with one atom having a +1 formal charge and another atom having a -1 formal charge, do these charges cancel each other out if there are only two atoms in the ion?

Thanks in advance!

Re: Formal Charges on Atoms Summed in Ions?

Posted: Tue Oct 29, 2019 3:59 pm
by connie 2C
can you provide an example? if it's just adding formal charges then yes they do cancel out.

Re: Formal Charges on Atoms Summed in Ions?

Posted: Thu Oct 31, 2019 8:34 pm
by Kelvin Chung 1C
In an ion, generally the formal charges should add up to the charge of the ion. In a molecule, I believe the formal charges should add up to 0.

Re: Formal Charges on Atoms Summed in Ions?

Posted: Thu Oct 31, 2019 9:23 pm
by Jocelyn Thorp 1A
Kelvin Chung 1C wrote:In an ion, generally the formal charges should add up to the charge of the ion. In a molecule, I believe the formal charges should add up to 0.


exactly. for example Na has a formal charge of +1 and Cl has a formal charge of -1. Their combined compound NaCl has a formal charge of zero.

Re: Formal Charges on Atoms Summed in Ions?

Posted: Fri Nov 01, 2019 9:44 am
by Jordan Ziegler 2J
In covalent bonding with a zero charge, the formal charges will always work out to cancel each other out.

For example, the least stable resonance hybrid of HClO4 has all single bonds. The formal charges on three oxygens are -1 (6 valence - (1 bonding site + 6 lone electrons), and the formal charge on the central chlorine atom is +3 (7 valence electrons - 4 bonding sites). These formal charges will cancel each other out in the big picture of the molecule.

Re: Formal Charges on Atoms Summed in Ions?

Posted: Fri Nov 01, 2019 10:38 am
by romina_4C
If the molecule does not have a charge associated to it (a charge like ), then the formal charges should cancel out to zero. In the example of the molecule I mentioned the overall formal charges of the molecule should equal -2, since the molecule has a charge of -2.

Re: Formal Charges on Atoms Summed in Ions?

Posted: Fri Nov 01, 2019 1:10 pm
by Manav Govil 1B
Also, the more formal charges there are that equal to zero, the more stable the molecule actually is.