1-Naphthalenesulfonic acid, 3-hydroxy-4-[(1-hydroxy-2-naphthyl)azo]-7-nitro-, monosodium salt
Mordant Black T
CAS: 1787-61-7
Molecular Formula: C20H12N3NaO7S
1-Naphthalenesulfonic acid, 3-hydroxy-4-[(1-hydroxy-2-naphthyl)azo]-7-nitro-, monosodium salt - Names and Identifiers
1-Naphthalenesulfonic acid, 3-hydroxy-4-[(1-hydroxy-2-naphthyl)azo]-7-nitro-, monosodium salt - Physico-chemical Properties
| Molecular Formula | C20H12N3NaO7S |
| Molar Mass | 461.38 |
| Density | 1.109 g/mL at 25 °C |
| Flash Point | 185 °C |
| Water Solubility | 50 g/L (20℃) |
| Appearance | Form Powder/Solid, color Brownish-black to black |
| pKa | pK1:6.3;pK2:11.55 (25°C) |
| PH | 3.7 (10g/l, H2O, 20℃) |
| Storage Condition | room temp |
| Stability | Stable. Incompatible with strong oxidizing agents, strong reducing agents. |
| Sensitive | Easily absorbing moisture |
| MDL | MFCD00003935 |
| Physical and Chemical Properties | Chemical properties dark brown powder. Soluble in water, and red to paddle red; slightly soluble in alcohol, and brownish magenta; slightly soluble in acetone. It is dark blue in concentrated sulfuric acid and light reddish brown after dilution; it is withered orange in concentrated nitric acid. Its aqueous solution, adding concentrated hydrochloric acid has no big change; adding sodium hydroxide concentrated solution to turn brown light magenta. The solubility in water (90 ℃) is 25g/L. When dyeing, copper and iron are encountered, and the color light has a greater influence. |
| Use | Used for wool, wool and all kinds of wool fabric dyeing, can also be used for nylon dyeing |
1-Naphthalenesulfonic acid, 3-hydroxy-4-[(1-hydroxy-2-naphthyl)azo]-7-nitro-, monosodium salt - Risk and Safety
| Hazard Symbols | Xi - Irritant |
| Risk Codes | R36 - Irritating to the eyes |
| Safety Description | S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S39 - Wear eye / face protection. |
| UN IDs | UN 1230 |
| WGK Germany | 2 |
| RTECS | QK2197000 |
| TSCA | Yes |
| HS Code | 32041900 |
| Hazard Class | 6.1 |
| Packing Group | III |
| Toxicity | 32041900 |
1-Naphthalenesulfonic acid, 3-hydroxy-4-[(1-hydroxy-2-naphthyl)azo]-7-nitro-, monosodium salt - Upstream Downstream Industry
| Raw Materials | 1-Naphthol 2-Naphthol Sulfuric acid Sodium hydroxide Hydrochloric acid |
| Downstream Products | high tempreature leveler U-100 |
1-Naphthalenesulfonic acid, 3-hydroxy-4-[(1-hydroxy-2-naphthyl)azo]-7-nitro-, monosodium salt - Introduction
It can be dissolved in hot water, cooled into a red-brown solution, slightly soluble in alcohol, and brownish magenta; slightly soluble in acetone. In case of excessive hydrochloric acid, brown-purple precipitate is generated; in concentrated nitric acid, it is withered orange; in case of sodium hydroxide, it is dark blue, then turns red, dissolves in concentrated sulfuric acid to form a blue-black solution, and forms a brown precipitate after dilution. The solubility in water (90 ℃) is 25g/L. Copper is encountered during dyeing; iron, color and light have a greater influence.
Last Update：2022-10-16 17:14:31
1-Naphthalenesulfonic acid, 3-hydroxy-4-[(1-hydroxy-2-naphthyl)azo]-7-nitro-, monosodium salt - Nature
| solubility | 50g/l |
| color index | 14645 |
| Specific gravity | 1.109 |
| Odor | Odorless |
| Merck | 14,3667 |
| BRN | 4121162 |
| EPA chemical information | C. I. Mordant Black 11, monosodium salt (1787-61-7) |
Last Update：2024-04-10 22:29:15
1-Naphthalenesulfonic acid, 3-hydroxy-4-[(1-hydroxy-2-naphthyl)azo]-7-nitro-, monosodium salt - Uses and synthesis methods
introduction
Chrome black T indicator, also known as mordant black 11, alias Eilai chrome black T indicator, scientific name 1-(1-hydroxy-2-naphthylazo)-6-nitro-2-naphthol -4-sodium sulfonate is a comprehensive indicator for the determination of barium, cadmium, indium, magnesium, manganese, calcium, lead, scandium, strontium, zinc, zirconium, etc. Chromium black T indicator is also used as indicator when measuring the total hardness (total amount of calcium and magnesium ions) of water samples. When we 2001 and prepared the chrome black T indicator according to the sanitary standard for drinking water, we found that 9.1.3.6 of which only dissolved the chrome black T indicator with 95% ethanol and diluted it to 100ml. The resulting indicator was verified that the solution was dark purple red with water sample and pure water respectively, and the color of titration end point could not change.
detection principle
Chrome black T indicator is a commonly used metal indicator. There are three different colors in the solution, and when the pH value is less than 6.3, it is purple. The pH value is greater than 11.6 and orange. The pH value is blue between 6.3 and 11.6. Practice has proved that the most suitable pH value for chromium black T indicator is between 9.0 and 10.5. The solid chrome black T indicator is very stable and the quantity is not easy to control when used. The liquid chrome black T indicator is very convenient to use, but its aqueous solution can only be stored for a few days.
application
chrome black t indicator is a metal ion indicator commonly used in EDTA complexometric titration, especially suitable as an indicator of magnesium, but its aqueous solution has poor stability and is usually used in a solid mixture with KCl or NaCl. it is difficult to grasp the dosage when measuring in parallel. the color of the samples varies from depth to depth, and the discoloration at the end point is not very obvious, which often causes large errors and brings inconvenience to the analysis work.
Preparation
according to the characteristics of stable properties and easy solubility of solid chrome black t indicator in water and ethanol, water, 95% ethanol, glycerol and triethanolamine can be selected as solvents respectively. When using water, 95% ethanol or glycerol as solvent, 0.5g of chrome black T indicator must be added with 10ml of hardness buffer, then dissolved in water, 95% ethanol or glycerol and diluted to 100ml, instead of being directly dissolved in 95% ethanol and diluted to 100ml according to? 9.1.3.6 of the sanitary standard for drinking water. Dissolve triethanolamine, 0.5g chrome black T indicator in 100ml triethanolamine, and replace triethanolamine with up to 25ml ethanol to reduce the viscosity of the solution, because triethanolamine has the basicity of amines and no hardness buffer can be added.
the above chrome black t indicator liquid indicator is stored in the refrigerator in a brown bottle, which is convenient to use. Among them, the chromium black T indicator aqueous solution can only be stored for a few days due to polymerization and oxidation reactions; the chromium black T indicator ethanol solution can only be stable for about a month due to the volatility of ethanol; the chromium black T indicator glycerol Or triethanolamine solution can be stored for a longer time. Triethanolamine is the best of the four solvents, because it can not only slow down the polymerization rate of chrome black T indicator, but also can be used as a masking agent to eliminate the blocking effect of Fe3 + and Al3 + on chrome black T indicator when Ca2 + and Mg2 + are titrated by EDTA-Na2.
the chrome black t indicator is dark purple red, and the titrated water sample is also purple red, which cannot change the color of the titration end point and does not play the role of indicator. If the indicator is dropped into pure water, it will not appear as pure blue as it should be, but dark purple red. If the indicator prepared above titrates the water sample, the color of the titration end point changes obviously, if it is dropped into pure. In actual work, we use triethanolamine as solvent, prepare it in 0.5% proportion, store it in a brown drop bottle and store it in a refrigerator, which can be used for 1~2 years.
production method
The 6-nitro-1, 2, 4-acid oxygen (I. e. 6-nitro-2-hydroxy-1-diazonaphthalene-4-sulfonic acid) is coupled with 1-naphthol, After salting out, filtration, drying and other processes, the product is prepared. The external wind of the product is black-brown uniform powder, and the color light is similar to that of the standard product (blue gray & rarr; Blue light black), the strength is standard 100±3 (points), the moisture content is ≤ 5%, the water insoluble impurity content is ≤ 1%, the fineness (content of residue through 80 mesh sieve) is ≤ 5%, and the dyeing fastness on wool conforms to the standard product (sun fastness level 7, the fastness of brown color such as soaping, water immersion, perspiration, cooking, carbonization, ironing, dry cleaning, etc. are all 4-5 grade, and the fastness of dry rubbing is 3-4 grade). Raw material consumption (kg/t) 6-nitro-1, 2, 4-acid oxygen (100%) 500 naphthol (100%) 255 caustic soda (100%) 255 soda ash (industrial) 215 hydrochloric acid (31%) 675 refined salt 450
Last Update：2024-04-10 22:29:15
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Supplier List
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Product Name: Eriochrome black T Visit Supplier Webpage Request for quotationCAS: 1787-61-7
Tel: 18301782025
Email: 3008007409@qq.com
Mobile: 18021002903
QQ: 3008007409
Wechat: 18301782025
Spot supply
Product Name: Eriochrome black T Visit Supplier Webpage Request for quotationCAS: 1787-61-7
Tel: 18301782025
Email: 3008007409@qq.com
Mobile: 18021002903
QQ: 3008007409
Wechat: 18301782025
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Raw Materials for 1-Naphthalenesulfonic acid, 3-hydroxy-4-[(1-hydroxy-2-naphthyl)azo]-7-nitro-, monosodium salt
Downstream Products for 1-Naphthalenesulfonic acid, 3-hydroxy-4-[(1-hydroxy-2-naphthyl)azo]-7-nitro-, monosodium salt