Eriochrome Black T- 25gm Packs

Eriochrome Black T is an organic azo dye widely used as a metallochromic indicator in analytical chemistry. Also known as Mordant Black 11 or Solochrome Black T, it forms coloured complexes with certain metal ions, particularly magnesium and calcium under suitable analytical conditions. It is commonly used in complexometric titrations with EDTA to determine water hardness and investigate metal-ion concentrations. The indicator exhibits a characteristic colour change near the titration endpoint, helping analysts identify changes in metal-ion binding. Eriochrome Black T is generally supplied as a brownish-black powder and is used in chemistry practicals, water analysis, and research laboratories. Its performance depends on the solution pH, buffer system, metal ions present, and the titration procedure. It is especially useful in educational and analytical laboratories studying complex formation and quantitative analysis. Appropriate personal protective equipment and safe chemical handling practices should be followed when preparing indicator solutions.

Product Specifications

Specification	Details
Appearance	Brownish-black powder
Assay	99%
Chemical Name	Eriochrome Black T
Alternate Names	Mordant Black 11, Solochrome Black T, C.I. 14645, Sodium 4-[(1-hydroxynaphthalen-2-yl)hydrazinylidene]-7-nitro-3-oxo-naphthalene-1-sulfonate
Molecular Formula	C₂₀H₁₂N₃NaO₇S
Empirical Formula	C₂₀H₁₂N₃NaO₇S
CAS Number	1787-61-7
Molecular Weight	461.38 g/mol
Grade	LR Laboratory Reagent

Key Features of Eriochrome Black T

• Organic azo dye used as a metallochromic indicator in complexometric analysis.
• Forms coloured complexes with selected metal ions under appropriate pH conditions.
• Provides a characteristic colour change during EDTA titrations involving suitable metal-ion systems.
• Useful for analytical chemistry practicals involving water hardness and metal-ion determination.
• Supports educational and research investigations into coordination chemistry and indicator behaviour.

Laboratory Applications of Eriochrome Black T

• Water hardness determination: Used as an indicator in EDTA complexometric titrations for estimating calcium and magnesium hardness under suitable buffered conditions.
• Complexometric titration practicals: Demonstrates the formation of metal-indicator complexes and endpoint detection in analytical chemistry experiments.
• Metal-ion analysis: Supports selected analytical procedures for determining suitable metal ions when the method specifies Eriochrome Black T.
• Coordination chemistry experiments: Helps illustrate interactions between metal ions, chelating agents, and metallochromic indicators.
• Analytical method development: Can be used to evaluate indicator response and endpoint behaviour in compatible titration systems.

Why Choose Lab Wale to Buy Eriochrome Black T

Lab Wale provides a sourcing option for laboratory chemicals and scientific supplies used by schools, colleges, universities, research centres, and analytical laboratories. When purchasing Eriochrome Black T, confirm the chemical identity, pack size, grade, and suitability for the intended analytical procedure. Reviewing available product specifications and safety documentation helps laboratories select appropriate materials and establish safe handling practices. Lab Wale supports laboratory purchasing requirements for educational experiments, water analysis, and research applications where a suitable metal-ion indicator is required.

Frequently Asked Questions About Eriochrome Black T

What is Eriochrome Black T used for in laboratories?

Eriochrome Black T is primarily used as a metallochromic indicator in complexometric titrations. Its most common analytical application is water hardness determination using EDTA, where it helps indicate the endpoint of titrations involving calcium and magnesium under suitable buffered conditions.

What is the molecular formula of Eriochrome Black T?

The molecular formula of Eriochrome Black T is C₂₀H₁₂N₃NaO₇S, and its molecular weight is approximately 461.38 g/mol. The formula is already expressed in the simplest whole-number ratio, so its empirical formula is the same as its molecular formula.

What is the CAS number of Eriochrome Black T?

The CAS Registry Number for Eriochrome Black T is 1787-61-7. It is also identified by the names Mordant Black 11 and Solochrome Black T, and by Colour Index number 14645. Confirm the product identity when selecting an indicator for a specific analytical procedure.

How does Eriochrome Black T work in EDTA titration?

Eriochrome Black T forms a coloured complex with certain metal ions at an appropriate pH. During an EDTA titration, EDTA binds the metal ions more strongly under suitable conditions, releasing the indicator and producing a characteristic endpoint colour change. A suitable buffer and validated method are essential for reliable results.

How should Eriochrome Black T be stored and handled?

Store Eriochrome Black T in a tightly closed, clearly labelled container in a cool, dry place, protected from moisture and contamination. Avoid inhaling dust and prevent contact with skin and eyes. Wear suitable gloves and eye protection, and follow the current Safety Data Sheet for handling, spill response, and disposal procedures.

Storage Conditions for Eriochrome Black T

Store Eriochrome Black T in a compatible, tightly closed container in a cool, dry, well-ventilated area protected from moisture and contamination. Keep it away from incompatible materials, including strong oxidising agents, and minimise dust formation during handling. Follow the product-specific Safety Data Sheet for recommended temperature limits and any additional storage precautions.

Precautions for Handling Eriochrome Black T

Review the current Safety Data Sheet before use and wear suitable laboratory gloves, safety goggles, and protective clothing. Avoid generating or inhaling powder dust and prevent contact with skin and eyes, as the material may cause irritation. Use appropriate ventilation during weighing and solution preparation. Clean spills using approved laboratory procedures and dispose of indicator solutions and contaminated materials according to institutional requirements.