| Methyl Red (pH indicator) | ||
| below pH 4.4 | above pH 6.2 | |
| 4.4 | ↔ | 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.
Read more about Methyl Red: Preparation, Methyl Red Test
Famous quotes containing the word red:
“Red lips are not so red As the stained stones kissed by the English dead.”
—Wilfred Owen (1893–1918)