What is Phenolphthalein?
Phenolphthalein is an organic compound which is used medicinally as a cathartic. It has a chemical formula C20H14O4. It is written as “phph” or HIn”. It is used in acid base titration as an indicator. As an indicator it turn pink to red in alkaline and is colorless in acid solutions. It is dissolved with alcohol for experiment purpose and it is slightly soluble in water. It is either yellowish-white to pale orange or white fine crystalline powder and in its liquid form it appears as a colorless till PH 8.5 and above that it appears as pink to deep red. It does not have taste and smell. This chemical compound is widely used as PH indicator and laboratory agent. Under acidic conditions when phthalic anhydride is condensed with two equivalents of pheno, Phenolphthalein is synthesized. It is a weak acid and belong to class of dyes called Pthalein dyes
Properties of Phenolphthalein – C20H14O4
|Molecular Weight/ Molar Mass||318.32 g/mol|
|Melting Point||258–263 °C|
Phenolphthalein structure – C20H14O4
C20H14O4 Uses (Phenolphthalein)
- It is used in acid base titrations as an indicator
- It is used in Kastle-Meyer test
- It was before used as a laxative
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