Formal Charge


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Madelyn Cearlock
Posts: 55
Joined: Thu Sep 27, 2018 11:19 pm

Formal Charge

Postby Madelyn Cearlock » 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!

ElliotPourdavoud 1A
Posts: 36
Joined: Thu Sep 27, 2018 11:16 pm

Re: Formal Charge

Postby ElliotPourdavoud 1A » 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.

Grace Kim 1J
Posts: 51
Joined: Thu Sep 27, 2018 11:18 pm
Been upvoted: 1 time

Re: Formal Charge

Postby Grace Kim 1J » 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

Millicent Navarro 1I
Posts: 53
Joined: Thu Sep 27, 2018 11:25 pm

Re: Formal Charge

Postby Millicent Navarro 1I » 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

Anmol_cheema_2F
Posts: 48
Joined: Thu Sep 27, 2018 11:26 pm

Re: Formal Charge

Postby Anmol_cheema_2F » 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

yea-lyn pak_1G
Posts: 30
Joined: Thu Sep 27, 2018 11:18 pm

Re: Formal Charge

Postby yea-lyn pak_1G » 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.

Anand Narayan 1G
Posts: 49
Joined: Thu Sep 27, 2018 11:15 pm

Re: Formal Charge

Postby Anand Narayan 1G » Mon Nov 26, 2018 8:56 pm

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

Arlene Linares 3A
Posts: 50
Joined: Thu Sep 27, 2018 11:25 pm

Re: Formal Charge

Postby Arlene Linares 3A » 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.

Jack Hewitt 4G
Posts: 36
Joined: Thu Sep 27, 2018 11:27 pm

Re: Formal Charge

Postby Jack Hewitt 4G » Thu Dec 06, 2018 6:21 pm

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


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