Question

What is the ph when 100 mL of 0.1 M NaOH is added to 150 mL of 0.2 M Hac if pka for acetic acid =4.76?

Answer 1

100 mL x 0.1M NaOH = 10 mmoles.
150 mL x 0.2M HAc = 30 mmoles.

............NaOH + HAc ==> NaAc + H2O
initial.....10......30......0......0
change.....-10.....-10.....10.....10
equil........0......20......10....10

Now substitute into the Henderson-Hasselbalch equation and solve for pH.

Answer 2

4.23