What is the Difference Between Nitric Acid and Nitrous Acid?

The key difference between nitric acid and nitrous acid lies in their molecular structure and acidic strength. Here are the main differences between the two:

1. Molecular Structure: Nitric acid (HNO3) has three oxygen atoms bound to a central nitrogen atom, while nitrous acid (HNO2) has only two oxygen atoms bound to a central nitrogen atom.
2. Acidic Strength: Nitric acid is a stronger acid than nitrous acid. The strength of an acid is determined by the stability of its conjugate base. In the case of nitric acid, the negative charge is distributed over three oxygen atoms, making it more stable and a stronger acid. In contrast, nitrous acid has an excessive negative charge spread over only two oxygen atoms, making it a weaker acid.
3. Resonance Effect: Nitric acid has a more powerful resonance effect due to the distribution of the negative charge over three oxygen atoms compared to nitrous acid, which has a less powerful resonance effect due to the distribution of the negative charge over only two oxygen atoms.

In summary, nitric acid is stronger than nitrous acid due to its molecular structure, which allows for a more stable and powerful resonance effect.

Comparative Table: Nitric Acid vs Nitrous Acid

Here is a table comparing the differences between nitric acid and nitrous acid:

Nitric acid and nitrous acid are both inorganic acids containing nitrogen atoms, but they have different chemical formulas, properties, and reactivities with metals.