Description
o-Cresolphthalein is a pure pH indicator reagent with CAS number 596-27-0, empirical formula C₂₂H₁₈O₄ and a molar mass of 346,39 g/mol. It is listed under EG number 209-881-8 and As a classic phthalein-type indicator, o-cresolphthalein is applied in acid–base titrations and pH-dependent colour-change procedures where a solid indicator of defined composition is required. The pure grade supports preparation of stock solutions and reproducible end-point detection in routine and research analytics. Available from manufacturer Carl ROTH, the material is packed to suit precise weighing on the analytical balance and subsequent dissolution in suitable solvents. Its placement among pH indicators makes it a practical choice for teaching laboratories, quality-control workflows and method development that rely on visual or photometric indication. provides a convenient working quantity while protecting the solid during storage and handling in the chemical store or on the bench.
This article is part of Reference substances & reagents (other), in Analytical standards & reference materials.
Key features
- Appearance: white to light yellow to light brown powder
- Absorption max. (NaOH 0,1 mol/l): 565-569 nm
- pH-transition range: 8.2 (colourless) - 9.8 (red violet)
- Loss on drying: ≤0.5 %
- CAS number: 596-27-0
- Pack sizes: 5 g, 25 g, 100 g
- EG nr.: 209-881-8
- Empirical formula: C₂₂H₁₈O₄
- Molar mass: 346,39 g/mol
- Technical Information Sheet:
- Safety Data Sheet:
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Questions about o-Cresolphthaleine, pure, 5 g, glass
What is this article?
o-Cresolphthaleine, pure, 5 g, glass is the article on this page. Luminix Health distributes Carl Roth for laboratory use. It sits in Reference substances & reagents (other), inside Analytical standards & reference materials, in Lab chemicals.
A reference substance has a stated identity and a stated content, used to check a method or to standardise a titration. It is a more tightly specified article than a reagent grade bottle of the same name. The lot's certificate is part of the product.
A reference material is the article against which another result is compared. Its value is stated, and the uncertainty of that value is part of the product. An ICP or ion standard is a solution of known concentration. A volumetric standard is for titration. A chromatography standard is the peak you match. The grade names, including pharmacopoeia and ASTM, say which impurities were limited. Identity is checked on PubChem. Names follow IUPAC. Medicinal grades follow the European Pharmacopoeia and USP.
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The category is Analytical standards & reference materials. The sub-category is Reference substances & reagents (other). The catalogue is Lab chemicals.
Shelves beside this one are ICP, AAS & ion standards, Chromatography standards (GC, HPLC, pesticides), Volumetric standard solutions (titration), Reagents for analysis (Ph. Eur., ASTM, DIN), Spectroscopy & physical property standards and Indicators & indicator solutions.
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