Question

What is the ph of a solution that has 0.075 m ch3cooh and 0.050m nach3coo present? ka for acetic acid = 1.80 x 10-5?

Answer 1

Hello!

For solving this problem we first have to determine the pKa of CH₃COOH.

$pKa=-log(Ka)=-log( 1,80*10^{-5} )=4,74$

Now, we use the Henderson-Hasselbach's equation to determine the pH of the buffer solution:

$pH=pKa+log (\frac{NaCH_3COO}{CH_3COOH} )=4,74+log( \frac{0,050M}{0,075M} )=4,56$

So, the pH of this solution is 4,56

Have a nice day!