Question

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 KMnO₄, colourless to pink
• C. Phenolphthalein, colourless to pink
• D. Methyl orange, yellow to pinkish red colour

Answer 1

The Correct Option is C

Phenolphthalein is a suitable indicator for the titration of a strong base (sodium hydroxide) against a weak acid (oxalic acid). The end point is indicated by a colour change from colourless in acidic solution to pink in basic solution.