congo red

Definitions

  • WordNet 3.6
    • n congo red a red-brown azo dye especially as a chemical pH indicator (congo red is red in basic and blue in acidic solutions)
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Webster's Revised Unabridged Dictionary
    • Congo red (Chem) An artificial red dye from which the Congo group received its name. It is also widely used either in aqueous solution or as test paper (Congo paper) for the detection of free acid, which turns it blue.
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Usage

In literature:

The well-known dyes Congo Red and Bismarck Brown are azo compounds of complicated structure.
"The New Gresham Encyclopedia. Vol. 1 Part 3" by Various
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In news:

There is a tune called "Congo Blues" by the innovative white xylophone/vibraphone artist Red Norvo, recorded by him with Bird and Diz in '45, and also featured on a radio broadcast of Diz with a Coltrane tenor solo in 1951.
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