Respuesta :
Answer : The pH of the solution is, 5.22
Explanation :
First we have to calculate the moles of acetic acid and sodium acetate.
[tex]\text{Moles of acetic acid}=\text{Concentration of acetic acid}\times \text{Volume of acetic acid}=0.01M\times 0.025L=0.00025mol[/tex]
and,
[tex]\text{Moles of sodium acetate}=\text{Concentration of sodium acetate}\times \text{Volume of sodium acetate}=0.03M\times 0.025L=0.00075mol[/tex]
Now we have to calculate the concentration of acetic acid and sodium acetate in 1 L of solution.
[tex]\text{Concentration of acetic acid}=\frac{\text{Moles of acetic acid}}{\text{Volume of solution}}=\frac{0.00025mol}{1L}=0.00025M[/tex]
and,
[tex]\text{Concentration of sodium acetate}=\frac{\text{Moles of sodium acetate}}{\text{Volume of solution}}=\frac{0.00075mol}{1L}=0.00075M[/tex]
Now we have to calculate the pH of the solution.
Using Henderson Hesselbach equation :
[tex]pH=pK_a+\log \frac{[Salt]}{[Acid]}[/tex]
[tex]pH=pK_a+\log \frac{[\text{Sodium acetate}]}{[\text{Acetic acid}]}[/tex]
[tex]pK_a[/tex] of acetic acid = 4.74
Now put all the given values in this expression, we get:
[tex]pH=4.74+\log (\frac{0.00075}{0.00025})[/tex]
[tex]pH=5.22[/tex]
Thus, the pH of the solution is, 5.22
