Formal Charge Formula


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Michelle Shin 4B
Posts: 50
Joined: Thu Jul 25, 2019 12:17 am

Formal Charge Formula

Postby Michelle Shin 4B » Sat Oct 26, 2019 3:04 pm

What are the shared electrons (S) for the formula FC= V -(L + (S/2)) and how do you count them?

AnnikaMittelhauser4E
Posts: 50
Joined: Fri Aug 30, 2019 12:18 am

Re: Formal Charge Formula

Postby AnnikaMittelhauser4E » Sat Oct 26, 2019 3:23 pm

The shared electrons are the ones involved in bonding (the lines in Lewis structures). Each line counts as two shared electrons (so a double bond is 4 shared electrons).

For example, in H2O, the oxygen has 4 shared electrons because it has a single bond with each hydrogen. It then has 4 lone electrons (which makes sense because that gives it an octet). So FC = 6 - (4 + 4/2) = 0.

Emma Joy Schaetz 1E
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Joined: Wed Sep 18, 2019 12:16 am

Re: Formal Charge Formula

Postby Emma Joy Schaetz 1E » Sat Oct 26, 2019 3:25 pm

We count each shared electron twice, but then in the formula, it is divided by 2 to count for the sharing of the electrons.

Anokhi Patel 2B
Posts: 76
Joined: Fri Aug 09, 2019 12:17 am

Re: Formal Charge Formula

Postby Anokhi Patel 2B » Sat Oct 26, 2019 3:27 pm

The term "shared electrons" means that two atoms have formed a covalent bond. If you can count the two shared electrons for filling both of the atom's outer shells, then they are shared. To count the shared electron, the two electron between two atoms count are "2". To determine shared electrons, you can draw a circle around each atoms and its electrons and the electrons in the overlapped space are the shared electrons.

cassidysong 1K
Posts: 100
Joined: Fri Aug 30, 2019 12:15 am

Re: Formal Charge Formula

Postby cassidysong 1K » Sun Oct 27, 2019 7:51 pm

Shared electrons are the electrons that are represented by the line in a lewis dot structure. Each line counts as 2 electrons.

Natalie C 1K
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Re: Formal Charge Formula

Postby Natalie C 1K » Sun Oct 27, 2019 8:50 pm

shared electrons are the electrons that are involved in covalent bonds. since they are being shared, each atom receives one out of the 2, so you must divide by 2 because you are only calculating the formal charge for one of the atoms


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