Phenolphthalein 1% in 90% ethanol

Phenolphthalein or 3,3-bis (4-hydroxyphenyl) -1- (3H) -monobenzofuranone (the symbol φφ (phi-phi) or the general notation HIn, used for other indicators) is an organic compound of molecular formula C20H14O4 . It is a pH indicator (or a colored indicator), that is, a compound that changes color depending on the pH of the solution in which it is placed.

-PH indicator

Phenolphthalein is part of the phthalein family, that is, the colored indicators derived from triphenylmethane and which have an R-COO-R lactone ring.

In acid form, phenolphthalein is colorless, while the basic form is bright pink in color. The pK is 9.4, which means that the bend (i.e. the color change) of this indicator takes place in a base medium. The reversal zone is between pH = 8.2 (transition from colorless to pink) and 10.0. In other words, phenolphthalein is a marker for basic solutions, i.e. with a pH> 7.

Two other little known and very little used turning zones can characterize phenolphthalein. One is at pH ≈ 0, the molecule takes on an orange hue at negative pH. The other is in a very basic environment, the phenolphthalein then changes from pink to colorless very light pink color.

-Technical information

Density 0.82
Boiling point (bp) 78 ° C
Flash point (flp) 12 ° C • Melting point (mp) -114 ° C
ADR 3 II • WGK 3
UN No. 1170

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Hazard statements
H225 Highly flammable liquid and vapor
H319 Causes serious eye irritation
H341 Suspected of causing genetic defects
H350 May cause cancer

Safety recommendations
Precautions - prevention
P210 Keep away from heat. Do not smoke.
P280 Wear protective gloves / eye protection.

Precautions - response
P305 + P351 + P338 IF IN EYES: Rinse cautiously with water for a long period of time
amount of minutes; remove contact lenses, if possible; keep rinsing.
P308 + P313 NA (possible) exposure: Get medical attention.
For professional users only

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Phenolphthalein or 3,3-bis (4-hydroxyphenyl) -1- (3H) -monobenzofuranone (the symbol φφ (phi-phi) or the general notation HIn, used for other indicators) is an organic compound of molecular formula C20H14O4 . It is a pH indicator (or a colored indicator), that is, a compound that changes color depending on the pH of the solution in which it is placed.

-PH indicator

Phenolphthalein is part of the phthalein family, that is, the colored indicators derived from triphenylmethane and which have an R-COO-R lactone ring.

In acid form, phenolphthalein is colorless, while the basic form is bright pink in color. The pK is 9.4, which means that the bend (i.e. the color change) of this indicator takes place in a base medium. The reversal zone is between pH = 8.2 (transition from colorless to pink) and 10.0. In other words, phenolphthalein is a marker for basic solutions, i.e. with a pH> 7.

Two other little known and very little used turning zones can characterize phenolphthalein. One is at pH ≈ 0, the molecule takes on an orange hue at negative pH. The other is in a very basic environment, the phenolphthalein then changes from pink to colorless very light pink color.

-Technical information

Density 0.82
Boiling point (bp) 78 ° C
Flash point (flp) 12 ° C • Melting point (mp) -114 ° C
ADR 3 II • WGK 3
UN No. 1170

$$$$$

Hazard statements
H225 Highly flammable liquid and vapor
H319 Causes serious eye irritation
H341 Suspected of causing genetic defects
H350 May cause cancer

Safety recommendations
Precautions - prevention
P210 Keep away from heat. Do not smoke.
P280 Wear protective gloves / eye protection.

Precautions - response
P305 + P351 + P338 IF IN EYES: Rinse cautiously with water for a long period of time
amount of minutes; remove contact lenses, if possible; keep rinsing.
P308 + P313 NA (possible) exposure: Get medical attention.
For professional users only

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