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Formal Charge

Posted: Mon Nov 19, 2018 1:49 pm
by Madelyn Cearlock
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!

Re: Formal Charge

Posted: Mon Nov 19, 2018 2:16 pm
by ElliotPourdavoud 1A
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.

Re: Formal Charge

Posted: Mon Nov 19, 2018 3:38 pm
by Grace Kim 1J
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

Re: Formal Charge

Posted: Sat Nov 24, 2018 9:53 pm
by Millicent Navarro 1I
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

Re: Formal Charge

Posted: Sat Nov 24, 2018 11:05 pm
by Anmol_cheema_2F
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

Re: Formal Charge

Posted: Sat Nov 24, 2018 11:33 pm
by yea-lyn pak_1G
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.

Re: Formal Charge

Posted: Mon Nov 26, 2018 8:56 pm
by Anand Narayan 1G
The one I find the most helpful is # of valence electrons - (Lone electrons + Bonds)

Re: Formal Charge

Posted: Wed Nov 28, 2018 12:04 am
by Arlene Linares 3A
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.

Re: Formal Charge

Posted: Thu Dec 06, 2018 6:21 pm
by Jack Hewitt 2H
Number of valence electrons - (number of lone electrons + number of lines drawn)