Answer: The pH of the solution is 2.74.
Explanation:
To calculate the pH of the acidic buffer, the equation for Henderson-Hasselbalch is used:
[tex]pH=pK_a+\log (\frac{\text{[conjugate base]}}{\text{[acid]}})[/tex] .......(1)
The power of the acid dissociation constant is the negative logarithm of the acid dissociation constant. The equation for it is:
[tex]pK_a=-log K_a[/tex] ......(2)
The chemical equation for the reaction of acetic acid and NaOH follows:
[tex]CH_3COOH+NaOH\rightleftharpoons CH_3COONa+H-2O[/tex]
Given values:
[tex]K_a=1.8\times 10^{-5}[/tex]
Putting values in equation 2:
[tex]pK_a=-log (1.8\times 10^{-5})\\\\pK_a=4.74[/tex]
We are given:
[tex]CH_3COOH[/tex] = 0.1 M
[tex]CH_3COONa[/tex] = 0.001 M
Plugging values in equation 1:
[tex]pH=4.74+\log (\frac{0.001}{0.1})\\\\pH=4.74-2\\\\pH=2.74[/tex]
Hence, the pH of the solution is 2.74.
