Question

The pK_a of acetic acid and pK_b of ammonium hydroxide are 4.76 and 4.75 respectively. Calculate the pH of ammonium acetate solution.

Answer 1

Given, 

pK_a = 4.76 

pK_b = 4.75 

∵ pH = 7 + \(\frac{1}{2}\) [pK_a − pK_b] 

= 7 + \(\frac{1}{2}\) [4.76 - 4.75] 

= 7 + \(\frac{1}{2}\) [0.01] 

= 7 + 0.005 

= 7.005