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Acids, bases and titration — Question 27

QCAA 2023, Paper 1 · 6 marks

Q27 · 2023 · Paper 1Unclassified6 marks

QUESTION 27 (6 marks)

An unknown monoprotic acid solution was titrated with 0.1 M NaOH(aq).

Chemistry question figure

(a) Use Le Châtelier’s principle to explain why phenolphthalein is a suitable indicator for this titration.

[4 marks]

(b) Predict whether the pH of the equivalence point and the volume of NaOH required to neutralise the acid would change if the concentration of NaOH was doubled to 0.2 M.

[2 marks]

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