HNO3, known as nitric acid, is classified as a strong acid. This means that when it dissolves in water, it completely ionizes, releasing a high concentration of hydrogen ions (H+). The complete ionization in aqueous solution is what distinguishes strong acids from weak acids, which only partially ionize in solution.
To understand why nitric acid is a strong acid, consider how acids and bases behave in solutions. Strong acids, like HNO3, donate protons freely and result in a significant change in pH, making the solution highly acidic. In contrast, weak acids, such as acetic acid (CH3COOH), only partially dissociate in solution, leading to a less significant increase in hydrogen ion concentration and a higher pH compared to strong acids.
So, in summary, HNO3 is a strong acid due to its complete ionization in solution and its ability to donate protons efficiently. It is not a base at all, whether strong or weak.