Product Description
Methyl Red typically appears as lustrous purple crystals or a reddish-brown powder. It is nearly insoluble in water but dissolves easily in ethanol, chloroform, and acetic acid. The compound is primarily used as a pH indicator in acid-base titrations, allowing for precise determination of the titration endpoint through visible color changes.
Properties
| Melting point | 179-182 °C (lit.) |
| Boiling point | 412.44°C (rough estimate) |
| density | 0.839 g/mL at 25 °C |
| bulk density | 300-500kg/m3 |
| vapor density | 9.3 (vs air) |
| refractive index | 1.5930 (estimate) |
| Fp | 11 °C |
| storage temp. | Store at +5°C to +30°C. |
| solubility | ethanol: soluble1mg/mL |
| form | Solid |
| pka | 4.95(at 25℃) |
| Colour Index | 13020 |
| color | Reddish-violet |
| PH Range | 4.4(red)-6.3(yellow) |
| Odor | Odorless |
| Water Solubility | Practically insoluble in water. Soluble in alcohol, acetic acidSoluble in ethanol. Insoluble in water. |
| λmax | 410nm, 530nm, 427nm, 519nm |
| ε(extinction coefficient) | ≥10000 at 282-288nm in methanol |
| ≥20000 at 509-519nm in methanol | |
| ≥7000 at 329-335nm in methanol | |
| Merck | 146119 |
| BRN | 750102 |
| Stability: | Stable. Incompatible with strong oxidizing agents. |
| Major Application | Waveguides, LED sensors, photoresists, liquid crystals, sol-gel matrix, optical sensors, paints, toys, detection of thiols, food freshness sensors, dental product, saliva sampling method, detecting lactic acid, carbohydrates |
| InChIKey | CEQFOVLGLXCDCX-MSUUIHNZSA-N |
| CAS DataBase Reference | 493-52-7 |
| NIST Chemistry Reference | Benzoic acid, 2-[[4-(dimethylamino)phenyl]azo]-(493-52-7) |
| IARC | 3 (Vol. 8, Sup 7) 1987 |
| EPA Substance Registry System | Methyl red (493-52-7) |
Product Usage
Methyl Red is used as an indicator in a 0.1% alcoholic solution, showing red at pH 4.4 and yellow at pH 6.2. It is suitable for titrating ammonia and weak organic bases, such as alkaloids, but is not recommended for most organic acids, except oxalic and picric acid. Methyl Red can be easily reduced, causing a loss of color, so readings should be taken promptly. It is increasingly being replaced by more stable sulfonphthalein indicators, such as bromcresol green, which provide a sharper color change.
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Company Profile
Shandong Rongsheng Chemical Co., Ltd. operates within a key chemical‑focused industrial zone of Shandong Province. As a full‑service chemical enterprise integrating manufacturing, research & development, domestic sales and cross‑border export services, our core offering covers basic chemical raw materials and high‑performance fine‑chemical additives. Our product portfolio serves diverse downstream sectors, including rubber and plastic processing, coating and ink production, water‑treatment engineering, and multiple areas of general industrial manufacture.
With our in‑house standardized production base, we carry out strict quality monitoring across every production stage and provide genuine factory‑direct supply. By removing intermediate trading links, we deliver flexible procurement solutions for global buyers: large‑volume bulk supplies, custom formula development, personalized packaging options, as well as small‑batch sample orders. Our adjustable production capacity allows us to guarantee stable lead‑times to meet varied customer specifications.
Our experienced foreign‑trade team boasts abundant hands‑on experience servicing international chemical markets. Well‑acquainted with import regulatory requirements and cross‑border logistics rules for different countries and regions, we deliver complete end‑to‑end export support for overseas clients. Our service scope includes inquiry reception, sample shipment, custom solution design, customs clearance, cargo coordination and consistent post‑sales follow‑up.
We adhere to our operating principle of quality‑driven development and integrity‑based win‑win collaboration. Drawing on stable product quality, flexible service frameworks and efficient, fully‑compliant shipment capacity, we supply cost‑effective and highly reliable one‑stop chemical supply‑chain solutions for global purchasers. We are committed to becoming your dependable long‑term business partner in worldwide fine‑chemical trade.
