Formal Charge Shortcut


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Jarrett Peyrefitte 2K
Posts: 102
Joined: Sat Aug 24, 2019 12:16 am

Formal Charge Shortcut

Postby Jarrett Peyrefitte 2K » Fri Nov 08, 2019 3:42 pm

What's an easy way to find the formal charge without having to write down the equation and plugin the numbers every time?

Kishan Shah 2G
Posts: 132
Joined: Thu Jul 11, 2019 12:15 am

Re: Formal Charge Shortcut

Postby Kishan Shah 2G » Fri Nov 08, 2019 4:29 pm

An easy way is to count the number of lone electrons, not lone pairs, and add that the number of bonds( so a single bond would be one bond, a double would be two bonds). Then subtract this value from the number of valence electrons for that element.

KaleenaJezycki_1I
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Joined: Sat Aug 17, 2019 12:18 am
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Re: Formal Charge Shortcut

Postby KaleenaJezycki_1I » Fri Nov 08, 2019 4:50 pm

Count the bonds around the atom as 1 electron and then count each lone pair as 2 electrons (count each dot you drew individually) and you want this to add up to the number of valence of electrons of the actual element. However if this is on a test then you should show the actual calculation.

Mariah
Posts: 104
Joined: Fri Aug 02, 2019 12:16 am

Re: Formal Charge Shortcut

Postby Mariah » Fri Nov 08, 2019 5:09 pm

KaleenaJezycki_4G wrote:Count the bonds around the atom as 1 electron and then count each lone pair as 2 electrons (count each dot you drew individually) and you want this to add up to the number of valence of electrons of the actual element. However if this is on a test then you should show the actual calculation.


My TA told us we don't have to show the actual calculation, as this trick is well known and helps to not overcomplicate formal charge.


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