1. Understand Oxidation States
* Oxidation states represent the hypothetical charge an atom would have if all its bonds were 100% ionic.
* The sum of the oxidation states in a neutral molecule must equal zero.
* Common oxidation states:
* Oxygen: -2 (except in peroxides)
* Hydrogen: +1 (except in metal hydrides)
2. Apply the Rules to HNO₃
* Oxygen: We have three oxygen atoms, each with an oxidation state of -2, giving a total of -6.
* Hydrogen: One hydrogen atom has an oxidation state of +1.
* Nitrogen: Let 'x' represent the oxidation state of nitrogen.
3. Set Up the Equation
The sum of the oxidation states must equal zero:
x + (+1) + (-6) = 0
4. Solve for x
x - 5 = 0
x = +5
Therefore, the oxidation state of nitrogen in HNO₃ is +5.
