## Formal Charge

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

Heidi Ibarra Castillo 1D
Posts: 60
Joined: Fri Sep 28, 2018 12:19 am

### Formal Charge

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

Jessica Chen 1F
Posts: 61
Joined: Fri Sep 28, 2018 12:17 am

### Re: Formal Charge

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
Posts: 62
Joined: Fri Sep 28, 2018 12:16 am
Been upvoted: 2 times

### Re: Formal Charge

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
Posts: 64
Joined: Fri Sep 28, 2018 12:15 am

### Re: Formal Charge

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
Posts: 24
Joined: Fri Sep 28, 2018 12:24 am

### Re: Formal Charge

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
Posts: 23
Joined: Fri Sep 28, 2018 12:17 am

### Re: Formal Charge

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
Posts: 60
Joined: Fri Sep 28, 2018 12:19 am

### Re: Formal Charge

thank you !

Angel Chen 2k
Posts: 59
Joined: Fri Sep 28, 2018 12:20 am

### Re: Formal Charge

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
Posts: 59
Joined: Fri Sep 28, 2018 12:24 am

### Re: Formal Charge

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