What is the percent dissociation of glycine if the solution has a pH = 8.60 and a pK_a = 9.60? A)50% B)9% C)5% D)1%

Question

Quizplus · Accepted Answer

The percent dissociation of glycine can be calculated using the Henderson-Hasselbalch equation for the dissociation of the acidic group: pH = pKa + log([A-]/[HA]), where [A-] is the concentration of the dissociated form and [HA] is the concentration of the undissociated form. Given pH = 8.60 and pKa = 9.60, rearranging the equation gives log([A-]/[HA]) = pH - pKa = -1. Therefore, [A-]/[HA] = 10^-1 = 0.1. This means that for every 1 mole of HA, 0.1 moles of A- are formed, indicating a 10% dissociation. However, since the options do not include 10%, the closest provided option is 9%, suggesting a possible approximation or rounding in the question or answer choices.

What Is the Percent Dissociation of Glycine If the Solution