Consider the acidic buffer, a mixture of acetic acid and sodium acetate as.
CH3COOH ⇌ CH3COO– + H+ .....(1)
CH3COONa → CH3COO– + Na+ ....(2)
Applying law of mass action to (1),
Ka = \(\frac{[CH_3COO^-][H^+]}{[CH_3COOH]}\) ....(3)
Where, Ka is dissociation constant of weak acid.
In this solution, [ CH3COO–] ≅ [Salt] ....(4)
[CH3COOH–] ≅ [Acid] .....(5)
Substitute (4) & (5) in (3),
