In experiment concerning potentiometric determination of puriy and Ka of KHP, we obtained an experimental pKa of 5.04 and when compared with the theoretical pKa of 5.51, we obtained a % relative error of 192%.

Question

In experiment concerning potentiometric determination of puriy and Ka of KHP, we obtained an experimental pKa of 5.04 and when compared with the theoretical pKa of 5.51, we obtained a % relative error of 192%.
Could this error mean that a cerain impurity in the KHP sample effected this deviation?

DrBob222 · Answer

I think an impurity could introduce an error in this determination.