The following plot below shows a titration curve for the titration of 1.00 L of 1.00 M diprotic acid H2A with NaOH. Which point(s) a-d represent(s) the H 2X/HX - buffer region?
(a) point a
(b) point b
(c) point c
(d) point d
(e) points a and c
We’re being asked to determine which point(s) a–d represent(s) the H2X/HX– buffer region, given the following titration curve for the titration of 1.00 L of 1.00 M diprotic acid H2A with NaOH:
Since H2A is a diprotic acid, this means it has two equivalence points.
Recall that the equivalence point is the point in a titration curve where the pH increases abruptly. In the given titration curve, the two equivalence points are represented by points b and d: