Question

For the titration between oxalic acid and sodium hydroxide, the indicator used is

• A. Potassium permanganate
• B. Phenolphthalein
• C. Litmus
• D. Methyl orange

Answer 1

Answer: (B)

Phenolphthalein

Oxalic acid is titrated against NaOH. Phenolphthalein is chosen because it changes color in a pH range between 8 – 10. It appears pink in basic solutions and colourless in acidic solutions.

In the case of a strong acid-strong base titration, this pH transition would take place within a fraction of a drop of actual neutralization, since the strength of the base is high.