Methyl Red CAS 493-52-7

Glossy purple crystals or reddish-brown powder. Melting point 180-182 ℃. Soluble in ethanol, glacial acetic acid, almost insoluble in water. Used for protozoan living dyeing; acid-base indicator, pH discoloration range 4.4 (red) ~ 6.2 (yellow); titration of ammonia, weak organic bases and alkaloids, but not suitable for organic acids other than oxalic acid and picric acid; Combined with bromocresol green and methylene blue to form a mixed indicator to shorten the color change range and improve the sensitivity of color change; adsorption indicator for precipitation titration, such as titration of fluoride ion with thorium nitrate; detection of free chlorine, chlorite and other oxidants.