Formal Charge


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Heidi Ibarra Castillo 1D
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Joined: Fri Sep 28, 2018 12:19 am

Formal Charge

Postby Heidi Ibarra Castillo 1D » Thu Nov 01, 2018 6:48 pm

How do you determine your V, L , and S?

Jessica Chen 1F
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Joined: Fri Sep 28, 2018 12:17 am

Re: Formal Charge

Postby Jessica Chen 1F » Thu Nov 01, 2018 7:36 pm

V is the # of valence electrons the atom has (look at the periodic table, count over groups from left to right)
L is how many lone electrons that element has on its Lewis structure
S is the number of shared electrons between multiple atoms' Lewis structures

Desiree1G
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Re: Formal Charge

Postby Desiree1G » Thu Nov 01, 2018 8:20 pm

V is for valence electrons, L is for lone pair of electrons, and then S is for shared electrons. Don't forget also the formula V-(L+S/2)

Henry Krasner 1C
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Joined: Fri Sep 28, 2018 12:15 am

Re: Formal Charge

Postby Henry Krasner 1C » Thu Nov 01, 2018 11:22 pm

V, as above stated valence electrons, can be calculated by looking at the periodic table for instance.
L, lone electrons, are the dots surrounding an element, made to represent an electron.
S, shared electrons, are the lines connecting two elements, thus "sharing" them.

Jack Mitchell 3J
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Joined: Fri Sep 28, 2018 12:24 am

Re: Formal Charge

Postby Jack Mitchell 3J » Thu Nov 01, 2018 11:25 pm

To find "s" write the Lewis dot structure and then count the number of bonds that they form. however, don't forget to divide it by two in the equation.

John Kim Lec3Dis3L
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Joined: Fri Sep 28, 2018 12:17 am

Re: Formal Charge

Postby John Kim Lec3Dis3L » Thu Nov 01, 2018 11:49 pm

Heidi Ibarra Castillo 1D wrote:How do you determine your V, L , and S?


Rules for determining FC from the notes from class:
1. Determine number of valence e- for each bound atom
2. Determine number of bonding electrons (S)
3. Determine number of lone e- pairs (L)
4. Determine number of valence e- for each free atom (V)

Heidi Ibarra Castillo 1D
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Joined: Fri Sep 28, 2018 12:19 am

Re: Formal Charge

Postby Heidi Ibarra Castillo 1D » Sun Nov 04, 2018 6:01 pm

thank you !

Angel Chen 2k
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Joined: Fri Sep 28, 2018 12:20 am

Re: Formal Charge

Postby Angel Chen 2k » Sun Nov 04, 2018 9:08 pm

Based on the definition of the formal charge, we can get an easier way to calculate it.

(Number of available valence electrons)-(dashes and dots)

--dashes are half of the bonding electrons (or bonding pairs)

--dots are the non-bonding electrons.

Hope this makes the calculation easier.

Lydia Luong 4L
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Joined: Fri Sep 28, 2018 12:24 am

Re: Formal Charge

Postby Lydia Luong 4L » Sun Nov 04, 2018 9:18 pm

v= valence electrons, l= lone pairs, s= shared electrons


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