Question

Why colour of solution change from wine red to blue at end point?

Answer 1

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the answer I got is_
EBT is blue in a buffered solution ( an aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa) at pH 10. It turns red when Ca2+ ions are added. The ions involved in water hardness, i.e. Ca2+(aq) and Mg2+(aq) change the steel blue colour of EBT indicator into wine red colour.

Answer 2

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