[mass]

I understand the equation and what it's all about. However, I don't get when to use it, can anyone show me a question where I can actually apply it?

[sjb]

Classically, the HH equation is used in buffer calculation.

With that in mind, a sample question might read:

Calculate the pH of a solution containing 0.50 M CH₃COOH, Ka = 1.8 x 10^-5, and 0.25 M sodium acetate, CH₃COONa.

Or

If a buffered aqueous solution pH of 4.5 is required, and you have 0.4M CH₃COOH (Ka = 1.8 x 10^-5) , what concentration of CH₃COONa do you require.

[Borek]

http://www.chembuddy.com/?left=pH-calculation-questions&right=pH-buffer-q1

http://www.chembuddy.com/?left=pH-calculation-questions&right=pH-buffer-q2