In which of the following does nitrogen have an oxidation state of +4?

The oxidation state of nitrogen in a compound can be determined by considering the electronegativity of the other elements it is bonded to and using the rules for calculating oxidation states. In the case of nitrogen dioxide (NO2), nitrogen is bonded to two oxygen atoms.

Oxygen typically has an oxidation state of -2. Since there are two oxygen atoms in NO2, their combined contribution is -4. To find the oxidation state of nitrogen, we set up the following equation:

Let the oxidation state of nitrogen be x.

x + 2(-2) = 0

This simplifies to:

x - 4 = 0,

which gives us x = +4.

Therefore, in nitrogen dioxide (NO2), nitrogen indeed has an oxidation state of +4. This understanding of oxidation states is critical in analytical chemistry, as it helps in predicting the behavior of substances in various reactions, understanding their reactivity, and analyzing compounds in a mixture.