## Formal Charge Equation

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

Emily Orozco L4
Posts: 22
Joined: Thu Sep 27, 2018 11:29 pm

### Formal Charge Equation

What is the shortcut for the formal charge equation?

Sydney Tay 2B
Posts: 38
Joined: Thu Sep 27, 2018 11:20 pm

### Re: Formal Charge Equation

I'm not entirely sure that there's a shortcut to the equation, but what we learned in lecture was that the formal charge = v - (l- b/2) where v is the number of valence electrons that the element has, l is the number of lone pair electrons that the atom has in the molecule, and b is the number of bonded electrons that it shares.

arif_latif_2G
Posts: 36
Joined: Thu Sep 27, 2018 11:23 pm

### Re: Formal Charge Equation

Formal Charge = Valence electrons - The number of electrons that are not in a bond(# of lone pairs * 2) - the number of bonds

Nell Mitchell 1E
Posts: 31
Joined: Thu Sep 27, 2018 11:16 pm

### Re: Formal Charge Equation

In terms of finding the the formal charge a "short cut" when looking at lewis structures is to just count each dot and line as 1 and add them all the together. The same thing as counting all unpaired electrons and adding it to 1/2 the # of bonds. Thats how one of the UAs taught it and it made it faster for me than using the formula.

Grace Diaz 3F
Posts: 30
Joined: Thu Sep 27, 2018 11:24 pm

### Re: Formal Charge Equation

The formal charge equation is as follows
Valence electrons of atom-(number of lone pair electrons+ bonded electrons/2)
it's pretty easy to count the difference by just looking at the structure.

Katelyn Phan 2A
Posts: 36
Joined: Thu Sep 27, 2018 11:23 pm

### Re: Formal Charge Equation

An easier way to look at the equation is:
FC = Valence electrons - (line + dots)

lines being the bonds
dots being the individuals in lone pairs

Michelle Cervantes 1H
Posts: 12
Joined: Thu Sep 27, 2018 11:18 pm

### Re: Formal Charge Equation

So we count the individual dots in the lone pairs not the number of pairs themselves to. I learned that Formal Charge =V-(L+S/2) where V= valence e, L was the number of lone pairs, and s=number of shared electrons. I'm just a little confused about the lone pairs as I keep counting them as pairs and not individual electrons.

Jasmin Argueta 1K
Posts: 42
Joined: Thu Sep 27, 2018 11:16 pm

### Re: Formal Charge Equation

The shortcuts my PLF taught me was FC=sticks+dots around the molecule

Ashley P 4I
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Joined: Wed Nov 15, 2017 3:04 am

### Re: Formal Charge Equation

Jasmin Argueta 1K wrote:The shortcuts my PLF taught me was FC=sticks+dots around the molecule

I love how simple this is\. Thank you for putting this on here. Do we count the sticks as having two electrons or just counting the litiral sticks?

shouse1f
Posts: 34
Joined: Thu Sep 27, 2018 11:18 pm

### Re: Formal Charge Equation

the formula for formal charge is FC= valence - (lone pairs + (shared/2))

Andreana Vetus 1A
Posts: 28
Joined: Thu Sep 27, 2018 11:17 pm

### Re: Formal Charge Equation

Ashley P 4I wrote:
Jasmin Argueta 1K wrote:The shortcuts my PLF taught me was FC=sticks+dots around the molecule

I love how simple this is\. Thank you for putting this on here. Do we count the sticks as having two electrons or just counting the litiral sticks?

I also learned this shortcut. The sticks just count as one!

davidbakalov_lec2_2L
Posts: 33
Joined: Thu Sep 27, 2018 11:23 pm

### Re: Formal Charge Equation

The shortcut to find the formal charge is to take valence electrons - (# of lines + # of dots)

Keshav Bhatnagar 1H
Posts: 32
Joined: Thu Sep 27, 2018 11:17 pm

### Re: Formal Charge Equation

Free valence electrons (based on periodic table ) - bonded valence electrons (based on the element given)

Millicent Navarro 1I
Posts: 37
Joined: Thu Sep 27, 2018 11:25 pm

### Re: Formal Charge Equation

The way I look at the formal charge equation is:
Number of valence electrons - (Lone pairs + Bonds)

# of valence electrons: Given through the periodic table based on their period position
Lone pairs: The number of "dots" around an element
Bonds: The number of "lines" in between two elements