Page 1 of 1

### Formal Charge Equation

Posted: Sun Nov 04, 2018 11:02 pm
What is the shortcut for the formal charge equation?

### Re: Formal Charge Equation

Posted: Sun Nov 04, 2018 11:09 pm
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.

### Re: Formal Charge Equation

Posted: Sun Nov 04, 2018 11:11 pm
Formal Charge = Valence electrons - The number of electrons that are not in a bond(# of lone pairs * 2) - the number of bonds

### Re: Formal Charge Equation

Posted: Sun Nov 04, 2018 11:17 pm
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.

### Re: Formal Charge Equation

Posted: Sun Nov 04, 2018 11:41 pm
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.

### Re: Formal Charge Equation

Posted: Mon Nov 05, 2018 9:41 am
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

### Re: Formal Charge Equation

Posted: Mon Nov 05, 2018 12:09 pm
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.

### Re: Formal Charge Equation

Posted: Thu Nov 08, 2018 7:09 pm
The shortcuts my PLF taught me was FC=sticks+dots around the molecule

### Re: Formal Charge Equation

Posted: Sun Nov 11, 2018 4:30 pm
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?

### Re: Formal Charge Equation

Posted: Sun Nov 11, 2018 7:15 pm
the formula for formal charge is FC= valence - (lone pairs + (shared/2))

### Re: Formal Charge Equation

Posted: Sun Nov 11, 2018 7:19 pm
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!

### Re: Formal Charge Equation

Posted: Sun Nov 11, 2018 7:59 pm
The shortcut to find the formal charge is to take valence electrons - (# of lines + # of dots)

### Re: Formal Charge Equation

Posted: Sun Nov 11, 2018 8:38 pm
Free valence electrons (based on periodic table ) - bonded valence electrons (based on the element given)

### Re: Formal Charge Equation

Posted: Sun Nov 11, 2018 8:49 pm
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