The oxidation number of nitrogen in dinitrogen pentoxide (N2O5) is +5.
Understanding Oxidation Numbers
Oxidation numbers, also known as oxidation states, represent the hypothetical charge an atom would have if all bonds were purely ionic. They are crucial for understanding chemical reactions, particularly redox (reduction-oxidation) reactions, by indicating the degree of oxidation (loss of electrons) or reduction (gain of electrons) of an atom in a chemical compound.
For a neutral compound like N2O5, the sum of the oxidation numbers of all atoms must equal zero.
Calculating the Oxidation Number of Nitrogen in N2O5
To determine the oxidation number of nitrogen in N2O5, we follow standard rules for assigning oxidation numbers:
- Oxidation Number of Oxygen: In most compounds, oxygen has an oxidation number of -2.
- Total Charge from Oxygen Atoms: N2O5 contains five oxygen atoms. Therefore, the total negative charge contributed by the oxygen atoms is 5 * (-2) = -10.
- Electrical Neutrality: Since N2O5 is a neutral compound, the total positive charge from the nitrogen atoms must balance the total negative charge from the oxygen atoms. This means the two nitrogen atoms must collectively have a total oxidation charge of +10.
- Oxidation Number per Nitrogen Atom: To find the oxidation number for a single nitrogen atom, we divide the total positive charge (+10) by the number of nitrogen atoms (2).
- Oxidation number of N = (+10) / 2 = +5
Summary of Oxidation Numbers in N2O5
| Element | Number of Atoms | Oxidation Number per Atom | Total Oxidation Charge |
|---|---|---|---|
| Nitrogen | 2 | +5 | +10 |
| Oxygen | 5 | -2 | -10 |
| Total | 0 |
This calculation confirms that each nitrogen atom in dinitrogen pentoxide has an oxidation number of +5.
