o -Cresolphthalein

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Structural formula
O-cresolphthalein, colorless form
General
Surname o -Cresolphthalein
other names
  • 3,3-bis (4-hydroxy-3-methylphenyl) -1 (3 H ) -isobenzofuranone
  • 5 ', 5' '- dimethylphenolphthalein
Molecular formula C 22 H 18 O 4
Brief description

colorless solid

External identifiers / databases
CAS number 596-27-0
EC number 209-881-8
ECHA InfoCard 100.008.985
PubChem 68995
Wikidata Q15634165
properties
Molar mass 346.38 g mol −1
Physical state

firmly

Melting point

219-221 ° C

safety instructions
GHS labeling of hazardous substances
no GHS pictograms
H and P phrases H: no H-phrases
P: no P-phrases
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

o -Cresolphthalein is a triphenylmethane dye and belongs to the phthalein family. The name is composed of o-cresol and phthalic anhydride . The corresponding sulfonphthalein is cresol red .

o -Cresolphthalein is used like phenolphthalein as a pH indicator . At a pH of 8.2 to 9.8, the color changes from colorless to red.

Individual evidence

  1. ↑ a b c d e data sheet o-cresolphthalein from Sigma-Aldrich , accessed on October 3, 2016 ( PDF ).