| Naphtholphthalein | |
|---|---|
|
3,3-bis(4-hydroxynaphthalen-1-yl)-2-benzofuran-1-one |
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Other names
1-Naphtholphthalein, alpha-naphtholphthalein, naphtholphthalein blue |
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| Identifiers | |
| CAS number | 596-01-0 |
| PubChem | 68993 |
| Beilstein Reference | 97816 |
| Jmol-3D images | Image 1 |
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| Properties | |
| Molecular formula | C28H18O4 |
| Molar mass | 418.44 g mol−1 |
| Appearance | Colorless-redish to blue-green solid |
| Melting point |
254 °C, 527 K, 489 °F |
| Solubility in water | Insoluble |
| Hazards | |
| Main hazards | Irritant (Xi) |
| (verify) (what is: /?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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| Infobox references | |
α-Naphtholphthalein (C28H18O4) is a pH indicator with a visual transition from colorless/reddish to greenish/blue at pH 7.3–8.7.