2024 Re-NEET EquilibriumAcid-base titration indicators Medium Question 12 of 104 in Equilibrium

Which indicator is used in the titration of sodium hydroxide against oxalic acid and what is the colour change at the end point?

A Phenolphthalein, pink to yellow
B Alkaline $KMnO_4$, colourless to pink
C Phenolphthalein, colourless to pink
D Methyl orange, yellow to pinkish red colour

The answer is C.

Solution

Oxalic acid (a weak acid) titrated against NaOH (a strong base) is a weak acid-strong base titration, for which phenolphthalein (which changes from colourless to pink near the equivalence point, in the basic pH range) is the appropriate indicator.

Concept Acid-base titration indicators

Equilibrium in past papers

104 questions from this chapter have appeared across 27 exam years.