Additional Information
Although calculating the pH of a monoprotic acid or base is quite simple, doing so for a polyprotic compound can often be much more complex. Polyprotic acids and bases have multiple ionizable hydrogen ions or hydroxide ions per molecule, and undergo multiple dissociation steps as a result. Furthermore, they may have different dissociation constants for each ionization step, which must be accounted for when calculating pH. In order to provide an accurate pH value for polyprotic compounds, this tool takes into account each of the dissociation constants and calculates the change in H+ or OH- concentration from each dissociation step. The tool also utilizes a univariate polynomial equation to find the exact concentration change in each step, rather than assuming that any of the dissociation constants are negligible.
It should be noted that while the pH calculation performed by this tool takes into account each dissociation step for polyprotic acids and bases, the ICE table only depicts the first dissociation step. In order to get a visual representation of the change in H+ or OH- concentration from each step for a polyprotic compound, multiple ICE tables must be computed using updated initial concentration values and the corresponding Ka value for each step.
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