NEETChemistryIonic Equilibrium
In the titration of acetic acid against sodium hydroxide, what is the nature of the solution at the equivalence point, and what is the working pH range of the most suitable indicator for this titration?
Options
- AAcidic, 3.1 - 4.4
- BBasic, 3.1 - 4.4
- CNeutral, 6.0 - 7.6
- DBasic, 8.0 - 9.8
Correct answer
D. Basic, 8.0 - 9.8
Step-by-step solution
Acetic acid ( CH₃COOH ) is a weak acid and sodium hydroxide ( NaOH ) is a strong base. At the equivalence point, the salt formed is sodium acetate ( CH₃COONa ). Sodium acetate is a salt of a weak acid and a strong base. It undergoes anionic hydrolysis, making the solution basic at the equivalence point ( pH > 7 ). The steep change in pH near the equivalence point for this titration lies in the basic region. Therefore, phenolphthalein is the most suitable indicator, which has a working pH range of approximately 8.0