Which indicator is most suitable for a titration of a strong acid with a weak base?
Answer and explanation
Correct answer: C. Methyl orange
- Step 1: The equivalence point is acidic (weak base salt hydrolyses), at about pH 4-6. Step 2. Methyl orange changes colour in the range 3.1-4.4. Answer: Methyl orange. Why not the others: phenolphthalein changes in basic range (8.3-10); universal indicator changes gradually and is not sharp; litmus has a broad range and a poor end-point.
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