Description
o-Cresol Red is an analytical pH indicator supplied in p.a. quality, with CAS number 1733-12-6 and empirical formula C₂₁H₁₈O₅S. Its molar mass of 382,44 g/mol supports accurate preparation of indicator stock and working solutions for acid–base titrations and pH monitoring. As a cresolsulfonphthalein dye, it is employed in analytical chemistry where distinct colour changes mark pH transitions in aqueous systems. The material is Available from manufacturer Carl ROTH, this reagent fits workflows focused on pH indicators and broader analytical chemicals. Defined molecular identity and p.a. grade help maintain consistency when standardising visual endpoint methods. Prepare solutions according to established laboratory procedures, store the solid under appropriate dry conditions, and refer to the safety data sheet for handling guidance before first use.
This article is part of Analytical grade solvents (p.a.), in Solvents.
Key features
- Appearance: green to dark red to dark brown powder
- Transition range: 6.5 - 8.8
- Dye content: ≥85 %
- Solubility in ethanol: complies
- CAS number: 1733-12-6
- Pack sizes: 5 g, 10 g, 25 g
- EG nr.: 217-064-2
- Empirical formula: C₂₁H₁₈O₅S
- Molar mass: 382,44 g/mol
- Technical Information Sheet:
- Safety Data Sheet:
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Questions about o-Cresol Red, p.a., 5 g, glass
What is this article?
o-Cresol Red, p.a., 5 g, glass is the article on this page. Luminix Health distributes Carl Roth for laboratory use. It sits in Analytical grade solvents (p.a.), inside Solvents, in Lab chemicals.
An analytical-grade solvent, often marked p.a., has impurity limits tight enough for classical analysis and for preparing reagents. It is not automatically low enough in UV absorbance for HPLC, and it is not dry enough for a water-sensitive reaction. The grade is the purchase.
A solvent dissolves. The grade says which impurities are low enough for the method. Analytical grade is the ordinary pure solvent. HPLC and LC-MS grades limit the absorbance and the ions that would become peaks or background. A dry solvent has had water removed. A deuterated solvent is for NMR, where the hydrogen signal would otherwise drown the sample. Technical grade is for cleaning and for synthesis that does not need a chromatogram. Identity is on PubChem. Names follow IUPAC. Hazards follow ECHA, the CLP Regulation and REACH.
Which category should I open next?
The category is Solvents. The sub-category is Analytical grade solvents (p.a.). The catalogue is Lab chemicals.
Shelves beside this one are HPLC & LC-MS grade solvents, Dry & deuterated solvents (NMR, synthesis), Technical & synthesis grade solvents and Green & alternative solvents.
What should I check before I order?
The technical information on this page is the manufacturer's sheet. Read that, not a rewritten specification.
When this page shows a safety data sheet, use that manufacturer file. Hazard text does not belong in the sales description. For a pack size, a grade or a certificate that is not on the page, send a quote request or contact the team.
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