Determine the pH of 263 ml of an aqueous solution which has [NH₄I] = 0.300 M.K_b = 1.74 × 10^-5 for NH₃(aq). A)2.6 B)11.4 C)4.9 D)9.1 E)4.6

Question

Quizplus · Accepted Answer

First, we need to determine the pKa value of NHS (N-hydroxysuccinimide). Using the given KS value, we can set up the following equation:

KS = [H+][NHS-]/[NHS]

1.74 × 10^-5 = [H+][NHS-]/0.300

[H+] = (1.74 × 10^-5) x (0.300) / [NHS-]

At the equivalence point, the amount of [H+] generated equals the amount of NHS- present. Therefore, we can assume that the [H+] equals 0.150 M (half the initial concentration of NHS).

pH = -log[H+]
pH = -log(0.150)
pH = 4.86

Therefore, the pH of the solution is approximately 4.9 (choice C).

Determine the PH of 263 Ml of an Aqueous Solution