This titration curve is produced when an acid is titrated with a sodium hydroxide solution of the same concentration - HSC - SSCE Chemistry - Question 16 - 2021 - Paper 1

To determine how many acidic protons this acid possesses, we analyze the titration curve. In general, the number of equivalence points in a titration indicates the number of acidic protons.

In the provided graph, it is important to identify the number of significant rises in pH. Each sharp increase in pH typically corresponds to an equivalence point. In this curve, there appears to be one main equivalence point around 12 mL of titrant addition, suggesting that the acid is likely diprotic. Thus, the answer is B. 2, indicating that the acid has two acidic protons.