Question

20 ml of 0.1 M acetic acid was mixed with 25 ml of 0.1 M Sodium Acetate. The pH was measured to be 4.43. 5 ml of 0.1 M Sodium Hydroxide was added to the buffer and the pH was measured to be 4.60. Calculate the pH of the buffer before and after the addition of NaOH.

Answer 1

I don't understand the problem. The problem states that the pH = 4.43, but the calculation gives a different number.

Answer 2

78