Percent Ionization

[Rachel Yu 1G]

HA + H2O <--> A- + H3O+

Is the equation for % ionization %=[A-]/[HA] x 100% or % = [H3O+]/[HA]? Most of the time I found that [A-] and [H3O+] tend to have the same concentration because they have the same stoichiometric coefficients. However, if there is a reaction where this isn't the case, which concentration would be used as the numerator and why?

[Ryan Lee 1E]

I think it would be the H30+ since that measures the actual amount of H+ that comes away from the acid.

[Renee Grange 1I]

From what I have in my notes I think its %=[A-]/[HA] x 100% , but I'm also confused about this.

[Ashley Tran 2I]

It's [H3O+]/[HA] x 100 because the percent ionization is measuring how much the acid [HA] gave up protons [H3O+] the [A-] is not involved.

[205405339]

its [A-]/[HA] but if [H30+]=[A-] then [H30+]/[HA] will yield the same % value