|Methyl Red (pH indicator)|
|below pH 4.4||above pH 6.2|
Methyl red (2-(N,N-Dimethyl-4-aminophenyl)azobenzenecarboxylic acid), also called C.I. Acid Red 2, is an indicator dye that turns red in acidic solutions. It is an azo dye, and is a dark red crystalline powder.
Methyl red is a pH indicator; it is red in pH under 4.4, yellow in pH over 6.2, and orange in between, with a pKa of 5.1.
Murexide and methyl red are investigated as promising enhancers of sonochemical destruction of chlorinated hydrocarbon pollutants.
Methyl red is classed by the IARC in group 3 - unclassified as to carcinogenic potential in humans.
Other articles related to "methyl red, red":
... At this pH, methyl red turns red ... A red color represents a positive test ... At this pH, methyl red is yellow ...
... the broth is separated into two different tubes, one for the methyl red (MR) test and one for the Voges-Proskauer (VP) test ... The pH indicator Methyl Red is added to one tube and a red color appears at pH's lower than 4.2, and indicated positive test ...
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