Eriochrome black T

: Sodium 4-[2-(1-hydroxynaphthalen-2-yl)hydrazin-1-ylidene]-7-nitro-3-oxonaphthalene-1-sulfonate; Solochrome Black T; ET-00

: E 1276

: 1787-61-7

: Indicator

: C₂₀H₁₂N₃NaO₇S

: 461.38

: Eriochrome Black T is a complexometric indicator that is used in complexometric titrations, e.g. in the water hardness determination process.

Colour Index Number 14645

: E 1276 (OTTO) Eriochrome black T Cas no 1787-61-7 - used as an indicator in an EDTA titration, the characteristic blue end-point is reached when sufficient EDTA is added and the metal ions bound to the indicator are chelated by EDTA, leaving the free indicator molecule.