Formal Charge vs Partial charge


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Ashley Odibo Dis3E
Posts: 31
Joined: Wed Nov 15, 2017 3:03 am

Formal Charge vs Partial charge

Postby Ashley Odibo Dis3E » Wed Nov 28, 2018 12:09 am

What is the difference between a formal charge and a partial charge and when should you use each?

Patrick Cai 1L
Posts: 56
Joined: Thu Sep 27, 2018 11:25 pm

Re: Formal Charge vs Partial charge

Postby Patrick Cai 1L » Wed Nov 28, 2018 12:32 am

Formal charge is determined by the formula FC = [# of valence electrons on atom] – [non-bonded electrons + number of bonds]; this is useful in determining whether or not a molecule is stable. Partial charge is a notation used to indicate that a molecule has an an asymmetrical distribution of charge (this is most prominently seen in polar molecules like H2O).

KatelinTanjuaquio 1L
Posts: 41
Joined: Thu Sep 27, 2018 11:16 pm

Re: Formal Charge vs Partial charge

Postby KatelinTanjuaquio 1L » Wed Nov 28, 2018 12:38 am

Formal charge is an atom's number of valence electrons minus number of dots and lines, which can more easily be seen in the following equation: an atom's number of valence electron - (number of lone pairs + (number of shared electrons/number of bonds). It is used when drawing Lewis Structures to ensure the overall molecule has the same charge as the indicated by the given molecular formula.

Partial charge is the charge of an atom in a molecule based the differences in electronegativity. However, this can change based on different interactions between other molecules. Partial charge is used when determining the type of intermolecular force and in turn, polarity.

Ivan Tadeja 4B
Posts: 31
Joined: Thu Sep 27, 2018 11:28 pm

Re: Formal Charge vs Partial charge

Postby Ivan Tadeja 4B » Fri Dec 07, 2018 8:41 pm

Formal charge is used primarily in lewis structures and molecular formulas and the charges (if any) on both must be equivalent. This gives us an indication of the stability of a molecule, with FC=0 being optimal.

Partial charge shows us electronegativity, and is a basis for determining how badly a molecule lose or gain an electron.

uhedlund
Posts: 32
Joined: Wed Nov 15, 2017 3:03 am

Re: Formal Charge vs Partial charge

Postby uhedlund » Sun Dec 09, 2018 11:21 pm

Formal charge shows the overall charge of an atom or molecule; partial charges can be used to indicate polarity of a molecule. For example, in H2O, the H atoms have a partial positive charge while the O atom has a partial negative charge.


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