Product name:Chlorophosphonazo III
CAS:1914-99-4
Molecular Formula:C22H16Cl2N4O14P2S2
Formula Weight:757.36
Description:
Specification:1g
Chlorophosphonazo-III is a colorimetric reagent for Th, U, lanthanoids, actinoids, and alkaline earth metals. This reagent is readily soluble in water and forms a violet color solution at pH 4 or lower, blue color in NaOH solution, and brilliant green color solutions in mineral acids such as H2SO4, HCl, diluted HNO3, but decomposes in concentrated HNO3. Its proton dissociation constants are reported to be -1.1, -1.1, 0.6, 0.8, 1.5, 2.5, 5.47, 7.20, 12.15 and 15.13 (m =0.1, 20 oC). Chlorophosphonazo-III is used as a selective colorimetric reagent for Ca in a Ca/Mg mixed sample in pH range 2-3. It is also a useful indicator for precipitation titration of SO42- by a standard solution of Ba2+.