Hello!
For solving this problem we first have to determine the pKa of CH₃COOH.
[tex]pKa=-log(Ka)=-log( 1,80*10^{-5} )=4,74[/tex]
Now, we use the Henderson-Hasselbach's equation to determine the pH of the buffer solution:
[tex]pH=pKa+log (\frac{NaCH_3COO}{CH_3COOH} )=4,74+log( \frac{0,050M}{0,075M} )=4,56[/tex]
So, the pH of this solution is 4,56
Have a nice day!
