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Acids, bases and titration — Question 48

Original QCE Vault practice · 4 marks

Q48 · Practice questionComplex familiar4 marks

QUESTION 48 (4 marks)

A student titrates a weak acid with strong base. Its steep pH change spans pH 7.5–10.5. Indicator X has pKa=4.0 and indicator Y has pKa=9.0.

a) Choose the more suitable indicator and justify using its transition range. [2 marks]

b) A burette is rinsed only with water before being filled with base. Predict the effect on the calculated acid concentration if the labelled base concentration is used. [2 marks]

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