Manufacturers and Suppliers of Chemicals, Reagent Ltd

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Phenolphthalein From ReAgent

If you require a phenolphthalien solution, we recommend

• Phenolphthalein 1%

If you require solid phenolphthalein, we recommend

• Phenolphthalein

We can also supply the following phenolphthalein solution:

• Phenolphthalein 0.5% w/v
• Phenolphthalein 0.2% w/v
• Phenolphthalein 0.05% w/v

Phenolphthalein is an indicator, and a very commonly used one at that. It is a white powder in pure form. One of the most frequent uses of this product is for detecting end-points in acid based titrations. For this application, phenolphthalein is effective for many different acids, such as hydrochloric acid.

To detect the strength of hydrochloric acid, begin by filling a vessel with hydrochloric acid. Then add some indicator, like phenolphthalein. It is worth noting at this point that phenolphthalein cannot be added directly, it should be dissolved in a solvent (e.g. Industrial Methylated Spirits (IMS) / Denatured Alcohol). Once the indicator has been added, the solution can then be titrated using a base of a known concentration, for example, sodium hydroxide. When the solution turns pink, it shows the end-point of the titration and you can calculate the strength of the hydrochloric acid from the amount of sodium hydroxide required.

Phenolphthalein is used more with stronger acids and bases. This is because it takes effect at a relatively high pH, between pH 8.3 and pH 10. Interestingly, phenolphthalein has been widely used as a laxative since its discovery. Please note however that all products manufactured supplied by ReAgent are not suitable for human consumption unless clearly stated.