Question

In: Chemistry

In each of the titrations performed in this experiment, the end point was apparent due to...

In each of the titrations performed in this experiment, the end point was apparent due to a color change in the material being oxidized or reduced. Suppose that none of the materials involved in the redox reaction are colored. Suggest a way one could determine the endpoint in such a case. (Hint= Think about acid-base titrations)

Solutions

Expert Solution

Acid - Base titration reactions are nothing but Neutralization reactions.

Let's take an example , Titration between NaOH and HCl.

Since both are colorless, we can't identify the completion (equivalence point) of reaction. In this case we need to use indicators which exhibits different colors in different mediums.

If we take Phenolpthalein as an indicator, it is colorless in acidic medium and pink color in basic medium.

If we add NaOH solution from burett to HCl solution + phenolpthalein indicator which is in Conical flask, initially reaction mixture is colorless , with the addition of more base at equivalent point color of solution changes to pink. This change in color indicates completion of reaction (end point).


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