Question

A 1.980 g sample of N-2-acetamido-2-aminoethane-sulfonic acid potassium salt (ACES K +,MW=220.29 g/mol ) is dissolved in 50.45 mL of water. To the solution, 13.55 mL of HCl is added, resulting in a pH of 6.73 . Calculate concentration of the HCl solution. The pK a of ACES is 6.85 .

Answer 1

The concentration of the HCl solution is 2.7 x 10^-5 M.

Step-by-step explanation:

To calculate the concentration of the HCl solution, we need to use the concept of equivalence point. The initial pH of the solution can be determined using the equilibrium constant (Ka) of ACES and the given concentration. Using the ICE approach, we can find that the initial pH is 2.87.

To find the concentration of the HCl solution, we can calculate the final pH of the solution when HCl is added. Based on the given pH of 6.73 and the pKa of ACES, we can determine that the final pH is 3.57. From this information, we can calculate the concentration of the HCl solution to be 2.7 x 10^-5 M.