Final answer:
The pKa of Z-123 is 2.98.
Step-by-step explanation:
The pKa of Z-123 can be determined using the pH of the solution.
The pH of the solution is found to be 2.98.
The pKa is equal to the pH when the concentration of the acid and its conjugate base is the same.
Therefore, the pKa of Z-123 is 2.98.