Orchem Products

Phenolphthalein indicator powder () is a white to yellowish-white, odorless crystalline powder used primarily as an acid-base titration indicator. It is insoluble in water but soluble in alcohols, changing from colorless in acidic/neutral solutions to pink/magenta in alkaline conditions, with a distinct transition range of pH 8.2–10.0.

Thymolphthalein is a white-to-yellowish crystalline powder, , used as a pH indicator that turns from colorless to blue in basic solutions. It has a transition range of pH 9.3–10.5, making it ideal for titrations in high-pH, non-aqueous, or alcohol-based solvents. It is soluble in alcohol and acetone, but insoluble in water. 

Methyl orange () is an orange-yellow, water-soluble crystalline powder used primarily as a pH indicator in titrations. It exhibits a distinct color change, appearing red in acidic solutions (below pH 3.1) and yellow in basic solutions (above pH 4.4). It is commonly used for, but not limited to, strong acid-weak base titrations.

Methyl orange powder () is an orange-colored, water-soluble azo dye used as a pH indicator in titrations, transitioning from red (pH < 3.1) to yellow (pH > 4.4). It is commonly used for strong acid-weak base titrations, appearing as a crystalline powder with a melting point over  

o-Cresolphthalein (CAS 596-27-0) is a phthalein dye and reversible pH indicator that changes from colorless to red-purple within a pH range of 8.2–9.8. It appears as a light brown/white powder, is insoluble in water but soluble in ethanol. It is primarily used in colorimetric assays for calcium determination.