Posted by Jessie on .
In titrations of acids and bases, what is the difference between the end point of the titration, and the equivalance point? Also, what is chemically occuring during the buffer zone? Thanks!
Good question and one that students sometimes have trouble with. The equivalence point is where the stoichiometry and chemistry indicates that the materials being titrated have exactly neutralized each other (in the case of acid and bases). The END point is where some arbitrarily chosen indicator tell us that we have finished the titration. We TRY to use an indicator which will turn at the equivalence point but most are not exactly at the equivalence point. Of course the pH at the equivalence point changes as we change the titrant and the material being titrated.
The pH changes for acid/base titrations as we change acids/bases. Redox titrations also have equivalence points and we try to use an indicator that has the E(voltage) value that is the same as that of the equivalence point.