Phenolphthalein
Phenolphthalein (CAS: 77-09-8), a triphenylmethane dye with the molecular formula C20H14O4, is a key pH indicator. It is colourless in acidic conditions and exhibits a distinct pink to fuchsia colour in basic environments, with a transition range of approximately pH 7.8-10.0. This compound is also utilised in scientific research as a model organic substance for studying molecular capture efficiencies. Phenolphthalein is supplied by TSS as a high-purity powder.
- IUPAC
- 3,3-Bis(4-hydroxyphenyl)-1(3H)-isobenzofuranone
- Synonyms
- 3,3-Bis(4-hydroxyphenyl)-1(3H)-isobenzofuranone3,3-Bis(p-hydroxyphenyl)phthalideEosin
pH Indicator in Titrations
Phenolphthalein is widely employed as a visual indicator in acid-base titrations. Its sharp colour change from colourless to pink signifies the endpoint of titrations involving strong bases and weak acids, or strong acids and strong bases, where the equivalence point falls within its transition range.
General Laboratory Reagent
In general laboratory settings, Phenolphthalein serves as a versatile pH indicator for determining the alkalinity of solutions. Its reliable colour change allows for quick qualitative assessments of basic conditions.
Research and Development
Phenolphthalein is used in specialised research applications, such as a model compound in studies evaluating the capacity of cyclodextrin constructs, including nanofibers, for molecular capture and separation.
| Molecular weight | 318.32 |
|---|---|
| Empirical formula | C20H14O4 |
| Assay | ≥98.0% |
| Grade | ACS reagent |
| Form | powder |
| Solubility | acetone: soluble |
| pH | 7.8-10.0 |
| Melting point | 261-263 °C(lit.) |
| Concentration | 1 % (w/v) |
| Application | Phenolphthalein is used as a general pH indicator. It is colorless in acidic solutions and turns pink in basic solutions. Phenolphthalein is also used as a model organic compound in the evaluation of the capture efficiency of various cyclodextrin constructs such as nanofiber-CD. |
Hazard statements
- H341Suspected of causing genetic defects
- H350May cause cancer
- H361Suspected of damaging fertility or the unborn child
Precautionary statements
- P201Obtain special instructions before use
- P281Use personal protective equipment as required
- P308IF exposed or concerned
| Protective equipment | Eyeshields, full-face particle respirator type N100 (US), Gloves, respirator cartridge type N100 (US), type P1 (EN143) respirator filter, type P3 (EN 143) respirator cartridges |
|---|---|
| Water hazard class (WGK, DE) | 3 |
| Hazard codes (EU) | T |
| Risk statements (R) | 45-62-68 |
| Safety statements (S) | 53-45 |
Hazard information is provided for guidance. Always consult the product Safety Data Sheet (SDS), available on request, before handling.
| Colour Index Number | 764 |
|---|
Documentation
Every batch ships with a Certificate of Analysis covering assay, identity and purity; the grade is confirmed against your enquiry. Safety Data Sheets and technical data sheets are available on request.
Supply & logistics
Samples for technical evaluation; bulk MOQ by grade and packaging. In-stock material ships in 7–10 working days, worldwide, with full export documentation.
What is Phenolphthalein used for?
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Phenolphthalein is primarily used as a pH indicator, showing a colourless to pink transition in alkaline solutions, and also serves as a model compound in research studies on molecular capture.
What is the CAS number and chemical formula for Phenolphthalein?
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The CAS number for Phenolphthalein is 77-09-8, and its chemical formula is C20H14O4.
What grade and purity does Tech Serve Solutions supply?
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Tech Serve Solutions supplies Phenolphthalein with an assay of ≥98.0%, conforming to the ACS reagent grade. We do not represent this product as USP, BP, EP, or any other pharmacopoeia grade.
What are the safety considerations when handling Phenolphthalein?
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Phenolphthalein is classified with GHS08 symbol, signalling 'Danger'. It carries hazard statements H341 (Suspected of causing genetic defects), H350 (May cause cancer), and H361 (Suspected of damaging fertility or the unborn child). Appropriate personal protective equipment, including eyeshields and suitable respiratory protection, is essential.
Is Phenolphthalein a controlled substance?
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While Phenolphthalein is not explicitly listed as a scheduled controlled substance in many jurisdictions, its classification as a potential carcinogen and mutagen warrants careful handling and adherence to all safety regulations.
How are Phenolphthalein products from TSS packed and shipped?
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Phenolphthalein is supplied as a powder. Specific packing and shipping details are handled in accordance with international regulations and customer requirements, ensuring safe transport. TSS exports globally.
How can I request a quote or sample of Phenolphthalein?
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To request a quote or a sample of Phenolphthalein, please contact our sales team through the dedicated portal on our website, providing your specific requirements.
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