Question

Use the titration curve for the weak acid to calculate the pH of a 0.150 M solution of that weak acid. Round the pKa to the nearest whole number for t___.

a) 2

b) 4

c) 6

d) 8

Answer 1

To calculate the pH of a 0.150 M solution of a weak acid using the titration curve, we need to find the pKa value. From the given information, the pH at the half-equivalence point (pK₂) is 4.74. option d.

Step-by-step explanation:

In order to calculate the pH of a 0.150 M solution of a weak acid using the titration curve, we need to find the pKa value of the weak acid. From the given information, we know that the pH at the half-equivalence point (pK₂) is 4.74.

Since the pK value is rounded to the nearest whole number, the nearest whole number for pKa would be 5. Therefore, the correct answer is option (d) 8.

At the equivalence point, the solution contains the titration product (acetate ion) and excess strong base. The pH is primarily determined by the amount of excess strong base. Using the given values, we can calculate that the pOH is 1.70, and therefore the pH will be 14 - 1.70 = 12.30. This pH is much higher than the pKa value, which is expected in the titration of a weak acid.