Formal Charge

[Just Joshin]

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This is from Kaplan:

It asks for the formal charge of nitrogen in NHO3.

The answer is +1. If O has a -2 charge, how is it that N will have a +1 charge?

What am I missing?

 

[Phlame217]

You're mixing up formal charge and oxidation states.

Formal charge:
Number of valence electrons - (Number of lone electrons + 1/2 bonded electrons)

In NHO3 Visualize the structure, N is the center with an H and 3 O's bonded

O...N...O
.....OH

N Valence = 5
O Valence = 6
H Valence = 1

One O is double bonded, One O is single bonded, and OH is single bonded.

Therefore Nitrogen has 4 electrons (8 bonded electrons/2 = 4)
5-4= +1

 

[Revilla]

YES, you're right! Just Joshin and I were PMing about this problem and I threw us both off by calculating oxidation state after confusing it for formal charge. My fault.

Thank you, Phlame217. Sorry, JJ! 🙂