### Formal Charge

Posted:

**Mon Nov 19, 2018 1:49 pm**Can someone explain the other way to determine the formal charge? The formula used in class confuses me and I am aware there is another, clearer way!

Created by Dr. Laurence Lavelle

https://lavelle.chem.ucla.edu/forum/

https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=33&t=36917

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Posted: **Mon Nov 19, 2018 1:49 pm**

Can someone explain the other way to determine the formal charge? The formula used in class confuses me and I am aware there is another, clearer way!

Posted: **Mon Nov 19, 2018 2:16 pm**

Another way is to count each electron that surrounds the atom in question and give it a value of 1 (ex. if an atom has 1 lone pair, you count both electrons as 1) then you count each bond as 1, (ex. if an atom has 2 bonds each bond is counted as 1) then you just add those values together and subtract from the valence electrons of the atom. Ex. If an atom has 6 valence electrons, and two lone pairs and two bonds, its formal charge is 0 because the 2 lone pairs = 4 and the two bonds = 2, 6-6= 0.

Posted: **Mon Nov 19, 2018 3:38 pm**

Instead of using the formula, a shortcut in finding the formal charge is (number of valence electrons - number of the dots/number of lines).

Here is a good youtube video I found explaining how to use the shortcut method!

Hope this helps!

https://www.youtube.com/watch?v=38fSDZypRB0

Here is a good youtube video I found explaining how to use the shortcut method!

Hope this helps!

https://www.youtube.com/watch?v=38fSDZypRB0

Posted: **Sat Nov 24, 2018 9:53 pm**

Personally, the way I look at calculating the formal charge is through this equation:

Number of valence electrons - (Lone pairs + Bonds)

# of valence electrons: Given through the periodic table based on their period position (Ex: Carbon has 4 V.E. because it is located in Period 4.)

Lone pairs: The number of "dots" around an element

Bonds: The number of "lines" in between two elements

Number of valence electrons - (Lone pairs + Bonds)

# of valence electrons: Given through the periodic table based on their period position (Ex: Carbon has 4 V.E. because it is located in Period 4.)

Lone pairs: The number of "dots" around an element

Bonds: The number of "lines" in between two elements

Posted: **Sat Nov 24, 2018 11:05 pm**

Basically the formula can be see as FC= # of valence electrons-( # of dots + # of lines)

the # of dots are just the lone pairs and the # of lines is just the S/2 or number of bonds between atoms

the # of dots are just the lone pairs and the # of lines is just the S/2 or number of bonds between atoms

Posted: **Sat Nov 24, 2018 11:33 pm**

You can just count the number of dots (each electron in a lone pair) and the number of lines (the number of pairs of electrons). Then subtract the number you counted from the number of valence electrons the atom has.

Posted: **Mon Nov 26, 2018 8:56 pm**

The one I find the most helpful is # of valence electrons - (Lone electrons + Bonds)

Posted: **Wed Nov 28, 2018 12:04 am**

Grace Kim 1E wrote:Instead of using the formula, a shortcut in finding the formal charge is (number of valence electrons - number of the dots/number of lines).

Here is a good youtube video I found explaining how to use the shortcut method!

Hope this helps!

https://www.youtube.com/watch?v=38fSDZypRB0

Thank you for the video.

Posted: **Thu Dec 06, 2018 6:21 pm**

Number of valence electrons - (number of lone electrons + number of lines drawn)