What is the pH of hydroiodic acid (HI)?
To determine the pH of hydroiodic acid (HI), we need to know the concentration of the acid and its dissociation constant. The dissociation constant of HI is the measure of its tendency to ionize in water and is denoted as Ka.
However, hydroiodic acid is a strong acid, which means it completely ionizes in water. As a result, the concentration of HI is equal to the concentration of H+ ions. So, the pH of hydroiodic acid can be directly calculated using the formula:
pH = -log[H+]
To find the concentration of H+ ions, you'll need the molar concentration (M) or the moles of HI present.
For example, if you have a 1 M solution of hydroiodic acid, then the concentration of H+ ions is also 1 M. Thus, the pH of this solution can be calculated as shown:
pH = -log(1) = 0
In this case, the pH of hydroiodic acid is 0, indicating it is a very strong acid.