The equivalence point was reached in titrations of three unknown acids at pH 9.16 (acid A), 8.88 (acid B), and 8.19 (acid C). (a) Which is the strongest acid? (b) Which is the weakest acid?

Video transcript

Hello everyone today. We have the following problem. Three unknown assets were titrate ID against a strong base. And the following pH values were noted when the equivalent points were reached which is the strongest and the weakest acid. So since the base in the titillation is a strong base, we don't have to worry about the conjugate acid from the base because the conjugate acids of strong bases are neutral. So the conjugate acids from the strong base will be neutral. So you must therefore only have a look at the conjugate base from the acid. So let's say that the acid is H. A. And our base is this strong base which is sodium hydroxide, react it we get the following. We then take that conjugate acid that we produced and we break that apart into sodium ions and the acid ions. So the a minus or the conjugate acid in this situation is basic. Which is why the ph of the equivalence points at all of these equivalents points are greater than seven. This means that their basic. And so conjugate bases of weak acids are basic. And we can apply the overall principle that the weaker an acid, the stronger the base. Therefore the acid with the highest ph should be the weakest acid. So the acid with the highest ph should be the weakest. Making that asset two, moreover, the acid with the lowest ph should be the strongest acid And this is therefore going to be acid one And Sophie said acid to is the weakest and acid one was the strongest. And with that we have answered the question overall, I hope this helped, and until next time.