3.24 is the pH of this monoprotic weak acid.
Let's assume monoprotic weak acid be AB
AB ⇄ A⁺ + B⁻
Formula used for Kₐ
Kₐ = [A⁺] [B⁻]/ [AB]
We can assume that the equilibrium concentrations utilized in the expression are a fair enough approximation to the original concentrations if Kₐ lies in the range 10⁻⁴ - 10⁻¹⁰.
This is relevant here.
Rearranging and taking both sides' negative logs results in:
pH = 1/2 log [pKₐ - logx]
where x represents the concentration of weak monoprotic acid.
pKₐ = -log Kₐ
Given
Kₐ = 2×10⁻⁶
So, pKₐ = - log(2×10⁻⁶) = 5.69
x = 0.16 M
Putting these values into the formula
pH = 1/2 [5.69 - ( -0.795)]
= 1/2 [5.69 + 0.795]
= 1/2[6.485]
= 3.24
Hence, 3.24 is the pH of this monoprotic weak acid.
Learn more about pH of acids here brainly.com/question/13779537
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