Okay let me write it this way.

Question

I mixed 30 mL of 0.1 M Acetic Acid and 15 mL of 0.1 M Sodium Hydroxide and measured the pH. Then I added 5 mL of 0.1 M NaOH to this buffer and measured the pH.

It's asking me:

Show the calculations for the pH of the buffer before and after the addition of HCL?

Thank You

Answer 1

I posted my response at the original post along with a note why I took so long to answer.

Answer 2

Ok. Thank you so much Dr. Bob