Answer:
pH = 10.20
Explanation:
The HClO reacts with NaOH as follows:
HClO + NaOH → H2O + NaClO
Where HClO and NaOH react in a 1:1 reaction.
As the concentration of both reactions is the same and the reaction is 1:1, to reach equivalence point are required the same 25.0mL.
And the NaClO produced decreases its concentration in 2 because the volume is doubled.
The concentration of NaClO is: 0.150M / 2 = 0.075M
The equilibrium of NaClO is:
NaClO(aq) + H2O(l) ⇄ HClO(aq) + OH-(aq)
Where Kb of reaction is 1.0x10⁻¹⁴ / Ka =
1.0x10⁻¹⁴ / 3.0x10⁻⁸ = 3.33x10⁻⁷ = [HClO] [OH-] / [NaClO]
[NaClO] = 0.075M
As both HClO and OH- comes from the same equilibrium,
[HClO] = [OH-] = X
Where X is the reactoin coordinate
Replacing:
3.33x10⁻⁷ = [X] [X] / [0.075M]
2.5x10⁻⁸ = X²
X = 1.58x10⁻⁴M = [OH-]
pOH = -log [OH-]
pOH = 3.80
pH = 14 - pOH
