Explanation:
It is given that the total volume is (10 mL + 60 mL) = 70 mL.
Also, it is known that =
Where, = total volume
= initial volume
Therefore, new concentration of =
=
= 0.43 M
New concentration of NaOH =
=
= 0.14 M
So, the given reaction will be as follows.
Initial: 0.43 0.14 0
Change: -0.14 -0.14 0.14
Equilibrium: 0.29 0 0.14
As it is known that value of = 4.74
Therefore, according to Henderson-Hasselbalch equation calculate the pH as follows.
pH =
=
= 4.74 + (-0.316)
= 4.42
Therefore, we can conclude that the pH of given reaction is 4.42.