Cresol Purple, Sodium Salt

OtherNames Phenol,4,4 -(3H-l,2-benzoxathiol-3-ylidene) w[3-methyl-,.S, .S-dioxide,monosodium salt 3H-l,2-Benzoxathiole, phenol derivative 

CA Index Name Phenol, 4,4 -(2,2-dioxido-3H-l,2-benzoxathiol-3-yhdene) [3-methyl-, monosodium salt 

CAS Registry Number 62625-31-4 Merck Index Number Not hsted Chemical Structure 

Chemical/Dye Class Sulfonephthalein Molecular Formula C iHi OjSNa Molecular Weight 404.42 pH Range 1.2-2.8 7.4-9.0 

Yellow (7.4) to purple (9.0) pKa 1.51, 8.32 Physical Form Black powder Solubility Soluble in water, ethanol UV-Visible (Xmax) 436 mn Melting Point 250°C Synthesis Synthetic methodi 

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A standard of pH 52 may be prepared by mixing 4.2 1 of 0.2 AT acetic acid with 158 cc. of o 2 AT sodium aceta while the 5.4 standard contains 29 cc. of the acid to 1 cc of sodium acetate solution Bromo-cresol purple may used as indicator The range 5.2 to 5.4 was determined wit out correcting for the protein or salt error. For details pH determinations the student is referred to Clark s book. 

Alizarin Alizarin Red S Alizarin Yellow R Benzopurpurine 4B 4,4 -Bis(2-amino-l-naphthylazo)-2,2 -stilbenedisulfonic acid 4,4 -Bis(4-amino-l-naphthylazo)-2,2 -stilbenedisulfonic acid Brilliant Yellow Bromocresol Green Bromocresol Purple Bromophenol Blue Bromothymol Blue Chlorophenol Red Clayton Yellow Congo Red o-Cresolphthalein Cresol Red Crystal Violet Curcumin (Turmaric) p-(2,4-Dihydroxyphenylazo) benzenesulfonic acid, sodium salt... 

Uses Acid-base (pH) indicator useful in the pH range 1.2 (red) - 2.8 (yel.) and 7.4 (yel.) - 9.0 (purple) commonly used as the water-sol. sodium salt or as a sol. in dilute sodium hydroxide Manuf./Distrib. Acros Org. http //www.acros.be-, Fluka http //www.sigma-aldrich.com, Lancaster Synthesis Pfaltz Bauer http //www.pfaitzandbauer.com, TCI Am. http //www.tciamerica. com Cresol red... 

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