Explanation:
The given reaction is as follows.
Hence, number of moles of NaOH are as follows.
n =
= 0.005 mol
After the addition of 25 ml of base, the pH of a solution is 3.62. Hence, moles of NaOH is 25 ml base are as follows.
n =
= 0.0025 mol
According to ICE table,
Initial: 0.005 mol 0.0025 mol 0 0
Change: -0.0025 mol -0.0025 mol +0.0025 mol
Equibm: 0.0025 mol 0 0.0025 mol
Hence, concentrations of HA and NaA are calculated as follows.
[HA] =
[NaA] =
Now, we will calculate the value as follows.
pH =
=
= 3.42
Thus, we can conclude that of the weak acid is 3.42.