Title: Naphthol Yellow S
CAS Registry Number: 846-70-8
CAS Name: 8-Hydroxy-5,7-dinitro-2-naphthalenesulfonic acid disodium salt
Additional Names: Citronin A; Sulfur Yellow S; Acid Yellow S; FD & C Yellow no. 1; Ext. D & C Yellow no. 7; C.I. Acid Yellow 1; C.I. 10316
Molecular Formula: C10H4N2Na2O8S
Molecular Weight: 358.19
Percent Composition: C 33.53%, H 1.13%, N 7.82%, Na 12.84%, O 35.73%, S 8.95%
Literature References: Prepn: Colour Index vol. 4 (3rd ed., 1971) p 4004.
Properties: Greenish yellow powder, sol in water to a yellow soln. The free acid is known as flavianic acid.
Use: Dye for wool, silk. |