Answer : The pH of a 0.1 M phosphate buffer is, 6.86
Explanation : Given,
[tex]pK_a=6.86[/tex]
Concentration of acid = 0.1 M
Concentration of conjugate base (salt) = 0.1 M
Now we have to calculate the pH of buffer.
Using Henderson Hesselbach equation :
[tex]pH=pK_a+\log \frac{[Salt]}{[Acid]}[/tex]
Now put all the given values in this expression, we get:
[tex]pH=6.86+\log (\frac{0.1}{0.1})[/tex]
[tex]pH=6.86[/tex]
Therefore, the pH of a 0.1 M phosphate buffer is, 6.86
