Molekula
Calcon (c.i. 15705) Pa
Supplying 4,500+ customers in over 80 countries
ISO 9001:2015 & ISO 14001:2015 certified · Supplying laboratories and industry since 2000 · Listed pack sizes are a starting point — we manufacture, source and repack to the quantity you need
Calcon (C.I. 15705 PA) is an azo metallochromic indicator used primarily for the complexometric EDTA titration of calcium in the presence of magnesium in analytical chemistry, including the determination of calcium in water samples. The titration is carried out at high pH, and the endpoint is a visual colour change from wine-red to blue. This product has a CAS number of 2538-85-4, with the molecular formula C20H13N2NaO5S and a molecular weight of 416.38. It is stored at ambient conditions and carries a signal word of "Warning" for safety. Molekula supplies Calcon from research to bulk quantities with full documentation and ISO 9001:2015 traceability.
Example image for illustration only. Other packaging and pack sizes are available.
Pricing & pack sizes
These pack sizes aren't a limit. Molekula manufactures, sources and repacks to order — if you need 500 kg and only see 1 kg listed, . We quote from grams to multi-tonne.
Need a different size? Add the nearest pack and change the size in your basket — we price it at the same rate per unit.
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5 g — $47.50 per pack
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50 g — $95.00 per pack
Need a different quantity or pack?
Tell us how much you need and when — drums, IBCs, sacks or a one-off bulk lot. We'll manufacture or source it and come back with a price.
Prices exclude VAT/sales tax and shipping.
Specifications
| Property | Value |
|---|---|
| Appearance | Dark brown or black powder |
| Solubility test in ethanol | Pass |
| Sensitivity of Aluminium | Pass |
| UV spectrometry | Pass |
Storage & handling
| Property | Value |
|---|---|
| Storage Temperature | Ambient |
| Flash Point | 125 °C |
Identification
| Property | Value |
|---|---|
| SKU | 74654588 |
| CAS Number | 2538-85-4 |
| IUPAC Name | sodium 3-hydroxy-4-[(2-hydroxynaphthalen-1-yl)diazenyl]naphthalene-1-sulfonate |
| EC Number | 219-810-2 |
| Molecular Formula | C20H13N2NaO5S |
| Molecular Weight | 416.38 |
| Exact Mass | 416.0443 |
| SMILES | C1=CC=C2C(=C1)C=CC(=C2N=NC3=C(C=C(C4=CC=CC=C43)S(=O)(=O)[O-])O)O.[Na+] |
| InChIKey | ZQWICJYATMSSSD-UHFFFAOYSA-M |
| InChI | InChI=1S/C20H14N2O5S.Na/c23-16-10-9-12-5-1-2-6-13(12)19(16)21-22-20-15-8-4-3-7-14(15)18(11-17(20)24)28(25,26)27;/h1-11,23-24H,(H,25,26,27);/q;+1/p-1 |
| PubChem CID | 135465074 |
| REACH Code | Y110 |
| TSCA Listed | Yes |
| HTS Code | 29270050 |
| Tariff Code | 2927000090 |
Safety & GHS
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Health Hazard
GHS07
Hazard statements
- H315 Causes skin irritation
- H319 Causes serious eye irritation
- H335 May cause respiratory irritation
Precautionary statements
- P261 Avoid breathing dust/fume/gas/mist/vapours/spray
- P280 Wear protective gloves/protective clothing/eye protection/face protection
- P302+352 IF ON SKIN: Wash with soap and water
- P305+351+338 IF IN EYES: Rinse with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing
Documents
Safety Data Sheets (SDS)
Available in English, French, German, Italian, Spanish.
Certificate of Analysis (CoA) by batch
Enter a lot or batch number to retrieve the CoA for that specific batch. We can generate one from spec data if no PDF is on file.
Synonyms
- CALCON
- Chromazine Blue Black R
- Chrome Fast Cyanine BSS
- Chrome Fast Cyanine GR
- Eriochrome Blue Black R
- Hispacrom Blue B
- Magracrom Blue
- Mordant Black 17
- Pontachrome Blue Black R
- Sunchromine Blue Black R
Frequently asked questions
What is Calcon (C.I. 15705) used for?
Calcon (C.I. 15705) is primarily used as a visual metallochromic indicator for the complexometric EDTA titration of calcium in the presence of magnesium at high pH, where the endpoint is a colour change from wine-red to blue.
What is the chemical formula and molecular weight of Calcon?
The chemical formula is **C₂₀H₁₃N₂NaO₅S**, and the molecular weight is **416.38 g/mol**.
How should Calcon be stored?
Store Calcon at **ambient temperature** in a dry, well-ventilated area, away from direct sunlight and incompatible substances.
What grade or purity is available for Calcon?
Molekula supplies Calcon in **analytical grade** purity, suitable for high-precision applications.
Can Molekula supply Calcon in bulk quantities?
Yes, we offer Calcon in bulk quantities upon request—please contact our sales team for pricing and availability.
What documentation comes with an order of Calcon?
Each order includes a **Certificate of Analysis (CoA)**, Material Safety Data Sheet (MSDS), and batch-specific documentation.
Ready to order or need a custom pack?
Tell us the product, grade, and quantity — Molekula usually responds within one working day with pricing and lead time.