Tuesday, June 28, 2022

What happens if too much indicator is added to a titration?

Compounds that change color when added to acidic or alkaline solutions are called indicators. Most of the time, colored indicators are used to determine the pH, and they can also be added to the reaction mixture to find out where the endpoint or equivalence point is for the different types of titration.

The indicator is selected based on the pH range that falls within the pH change of the reaction. In acid-base, redox, precipitation, and complexometric titration, different types of indicators are used. Each one has a pKa, a pH range. In chemistry, there are three types of indicators: natural indicators, artificial indicators, and olfactory indicators.

Why is it necessary to use a few drops of the indicator?

It is important to use no more than 2/3 drops of indicator solution since the indicator itself is a weak acid. Hence, we use only a few drops, as adding more can change the pH of the solution, and it can consume the titrant, which interferes with the actual reading of the analysis. 

Therefore, ideally, we would only need one or two drops, as this would give us an accurate color change at the equivalence or endpoint of the reaction.

Indicators are weak acids or bases that are usually made from plant pigments and have unique colors in their ionized and non-ionized states. These colors are related to the pH of the solution being analyzed. 

Phenolphthalein, methyl orange, phenol red, thymol blue, starch, eriochrome black-T, and potassium chromate are some of the examples of indicators.


People also ask:

What happens if too much indicator is added to a titration? (Does it affect the end point, is so why and how?)
Why is it important to use no more than 2/3 drops of indicator solution?
Why is it necessary to use few drop of the indicator?
What happens if you add too much phenolphthalein indicator?
Why is it important not to add too much indicator to the solution?
Why do we use two or three drops of indicator?
Why doesn't the indicator affect the titration results?


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