Hello!
To solve this question, we first have to know the pKa of the acid:
[tex]pKa=-log(Ka)=-log(5,66*10^{-7})=6,25 [/tex]
Now, we can apply the Henderson-Hasselbach's equation to determine the pH of the buffer solution:
[tex]pH=pKa+ log( \frac{[NaA]}{[HA]} )= 6,25 + log(\frac{(0,609 mol/2L)}{(0,506 mol/2L)})=6,33 [/tex]
So, the pH of this buffer solution is 6,33
Have a nice day!
