A buffer solution can be described as a solution, which will resist changes in pH when a small amount of a strong acid or base is added. An acidic buffer is compound of a weak acid and its conjugated base or a weak acid and the salt of the weak acid and a strong base. e.g., (CH3COOH+CH3COONa). CH3COOH⇌CH3COO−+H+ (feebly ionised) CH3COONa⇌CH3COO−+Na+ (completely ionised) How to make a acidic buffer (i) Start with taking weak acid (CH3COOH) and strong base (NaOH) in 2 : 1 molar concentration ratio, sothat a sufficient number of moles of the CH3COOH nutralize completely the same number of moles of NaOH. (ii) The acidic buffer can also be prepared by taking equimolar concentrations and volume of weak acid (CH3COOH) and the salt of the weak acid and strong base (CH3COONa).