Lacmoid

Name:
Lacmoid
Detailed information:

Chemistry name:	resorcinol blue
M Formula:	(HO)2C6H3N[C6H2(OH)3]2
Properties:
Lustrous, dark-violet, crystalline scales. Soluble in alcohol, ether, acetone, phenol, and glacial acetic acid; slightly soluble in water; pH 4.4–6.2.
Derivation:
From resorcinol by treatment with sodium nitrite.
Use:
Indicator in analytical chemistry (more sensitive than litmus).