methyl red

American  

noun

Chemistry.

1. a water-insoluble solid occurring as a dark-red powder or violet crystals, C 1 5 H 1 5 N 3 O 2 , used chiefly as an acid-base indicator.

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Etymology

Origin of methyl red

First recorded in 1905–10

Example Sentences

The hydrochloride of methyl red is only sparingly soluble in cold water, and is apt to separate in blue needles if the acidity is not sufficiently reduced.

From Organic Syntheses by Conant, James Bryant

The watery mother liquors from the crude methyl red are rendered alkaline with sodium hydroxide and distilled until no more dimethylaniline passes over.

From Organic Syntheses by Conant, James Bryant

The crystals of methyl red are filtered off and washed with a little toluene.

From Organic Syntheses by Conant, James Bryant

When the methyl red is crystallized from toluene, it sometimes separates in the form of bright-red lumps, probably on account of too rapid crystallization.

From Organic Syntheses by Conant, James Bryant

In the meantime a second conical flask containing 1250 cc. of toluene is attached to the funnel, and a new charge of 150 g. of crude methyl red is placed in the paper.

From Organic Syntheses by Conant, James Bryant