S P E C I F I C A T I O N S

PHENOL RED FREE ACID ACS

Synonyms:					Phenolsulfonephthalein

CAS No:					143-74-8

Chemical Formula:				C 19 H14O5S

Formula Weight:				354.38

Description:					Bright Red to Dark Red Powder

Identification:				Conforms to standard

Loss on drying:				5%  Maximum
( 110 ˚ C / 1 hour)			

Absorptivity (1%, 1cm)
(pH 6.5 at λ max. 431.0nm			600-700
(pH 8.2 at λ max. 558.0nm			1100-1200	

Clarity of solution:				To Pass Test

Visual transition Interval:			From pH 6.8 (yellow) 
To     pH 8.2 (red)

Solubility:					Slightly soluble in water, somewhat more
soluble in methanol, ethanol and acetic 
acid and readily soluble in alkaline 
solutions.

Effective: 12/30/12