Nomenclature
CAS number: 1395-18-2
Description and references
Purified coloring matter from litmus: I. M.
Kolthoff, C. Rosenblum, Acid-Base Indicators (MacMillan Co., New York, 1937) pp 160-162, 174, 208, 355, 361,
365-366, 368-369, 373, 377, 387.
Properties
Dark violet scales or dark red powder. Sparingly
soluble in water; insol in alc; freely sol in dil alkali hydroxides
or carbonates. The indicator solution is prepared by dissolving 0.5
g in 80 ml of warm H2O, then adding 20 ml alcohol.Use
Indicator instead of litmus. pH: 4.5 red, 8.3
blue. Usable with most mineral, some organic acids (not hydroxy acids)
and some alkaloids; also used for preparing litmus media for bacteriologic
purposes.