International name: Alizarin
CAS Number: 72-48-0
Appearance: orange-red crystals or brownish-yellow powder.
Description: Alizarin (1,2-dioksiantrahinon) C14H8O4 - one of the most organic dyes. Melting point = 290 ° C; boiling point = 430 ° C. Water solubility 0,034 g per 100 ml at 100 ° C. It is soluble in ethanol; soluble in hot methanol, benzene, acetic acid, carbon disulfide, pyridine and alkali. With multivalent metal salt gives a colored complex. Easily sublime. Recrystallized from ethanol. As pH indicator has two colors transition from pH 5.9 to 7.0 from yellow to dark pink; pH 10.1 to 12.0 with dark pink to purple.
Application:
Dyes of Alizarin used for dyeing fabrics. Apply the solution of aluminum fluoride, germanium, niobium, thorium, titanium, zirconium. niobium and tantalum. Photometric determining of alizarin aluminum, zirconium and fluoride.