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Acids, bases and titration — Question 104

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Q104 · Practice questionSimple familiar1 mark

QUESTION 104

An indicator has equilibrium HIn(aq)⇌H+(aq)+In−(aq) and pKa=6.0. HIn is yellow and In⁻ is blue. What is the expected dominant colour at pH 8.0?

(A)
Yellow, because HIn predominates.
(B)
Blue, because In⁻ predominates.
(C)
Green, because the two forms must have equal concentrations.
(D)
Colourless, because the indicator is completely consumed.
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