2) Phenolphthalein (C20H1404) is a dye very commonly used as indicator in acid-base titrations. The simplified generic expression for the dissociation of this molecule in water is shown in the equation below, where Hin
represents the phenolphthalein molecule and In is the phenolphthalein ion. Their appearance and relevant
properties are also shown below.
HIn (S) + H20 (1) = H30* (aq) + In" (aq)
a. Can this equilibrium be controlled by changing the pH of the solution? Briefly explain.
b. What color do you expect to see in the solution when you add acid to it? Briefly explain.