Question

Explain the Buffer Action of an Acidic Buffer.

Answer 1

The pH of an acidic buffer is less than 7.0. Normally it is made of weak acid and its salt.

For example, acetic buffer:

CH₃COOH(aq) + H₂O(l) <=> H₃O⁺(aq)+ CH₃COO^- (aq) 

Addition of NaOH (OH- ions) is neutralized by the acid:

CH₃COOH(aq) + OH^-(aq) –> CH₃CO₂^-(aq) + H₂O(l)    

Addition of HCl (H₃O⁺ ions) is neutralized by the conjugate base:

CH₃CO₂^-(aq) + H₃O⁺(aq) –> CH₃CO₂H(aq) + H₂O(l)