الوصف

Phenolphthalein: A 1% alcoholic soln as an indicator in titrations of mineral and organic acids and most alkalies. White or yellowish white minute, triclinic crystals, often twinned. mp ******2? d 1.**9. Sol in *5% alcohol and ether, slightly sol in chloroform. One gram dissolves in *2 ml alcohol, in ~**0 ml ether. Almost insol in water. Sol in dil solns of alkali hydroxides and hot solns of alkali carbonates forming a red soln. pKa (*5?C): 9.7. uv max (methanol): **5, **9, **6 nm (epsilon ****1.**7, ****2.**4, ***6.**9). Log P (octanol/pH 7.4): 2.4. Shows color change from colorless in acid range to purple at pH **9. Purity(Titration): min. *8.0% Solubility in Ethanol: to pass test Transition interval(pH): (colorless) 7.8 to *0.0 (ponceau) Absorbance(5mg/l, pH9.8): min. 0.*4