Titration question IB 2009

answer is A

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It’s the titration of super weak base and strong acid, so the end point would be much lower than pH 7. Therefore, we then need to use the indicator which optimal pH is much lower than 7. Unfortunately, only pKa values are given in the option, but we can know that the lower pKa indicates the stronger dissociation of the acidic solution(lower Ka value—> strong acid). So, we can deduce that the pH of bromophenol would be much lower than 7.