Can someone please help me here? It's review for my test. Thanks!

Question

Calculate the expected pH of the buffer prepared in Part I of this lab. The Ka
of acetic acid is 1.8 x 10-5

Calculate the expected pH when 10.0mL of 0.10M HCl is added to the buffer from question 3

Calculate the expected pH when 10.0mL of 0.10M NaOH is added to the buffer from question 3 (not the
one from question 4).

Answer 1

This is for part 1. Mix 50.0 mL of 0.20 M sodium acetate with 10.0 mL of 1.0 M acetic acid and 40.0 mL deionized water.