Question

Why is titration of weak acid against strong base ?

Answer 1

The graph shows how pH changes during titration of 50 cm³ of 0.1 M CH₃COOH with 0.1 M NaOH. 

CH₃COOH (aq) + NaOH (aq) → CH₃COONa (aq) + H₂O (l) 

The vertical portion of this titration curve lies between pH range 7 to 10.6. Phenolphthalein is suitable indicator for this titration. Methyl orange is not suitable for this titration because its pH range lies on the flat portion of the curve.