Hydroquinone CAS#123-31-9
High Solubility: Hydroquinone shows moderate solubility in water, and is readily soluble in polar organic solvents including ethanol, acetone and ether, while slightly soluble in benzene. This property enables it to be applied in various synthesis and formulation processes.
Antioxidant & Inhibition Performance: It acts as a highly effective polymerization inhibitor and antioxidant. It can prevent premature polymerization of vinyl monomers such as styrene, acrylic ester and acrylonitrile during storage and transportation.
Versatile Uses: It serves as a photographic developer for black-and-white films and papers, a key intermediate for dyes, rubber antioxidants and pharmaceutical products. It can also be used as analytical reagent and raw material for pesticide synthesis.
Crystalline Form & Sensitivity: This material appears as white crystalline solid. It is sensitive to light and air, and will gradually darken upon exposure. Proper sealed storage is required.
Hydroquinone, also named 1,4-Benzenediol, characterized by the molecular formula C₆H₄(OH)₂, presents as a white crystalline solid which tends to turn brown when exposed to light and air. It has moderate solubility in water (70 g/L at 25°C), freely soluble in ethanol, acetone and ether, and sparingly soluble in benzene. Its aqueous solution is weakly acidic. The substance has irritant and sensitizing properties, and is widely used as polymerization inhibitor, photographic developer, dye intermediate, rubber anti-aging agent and analytical reducing reagent for metal ions.
| Hydroquinone Chemical Properties | |
|---|---|
| Melting point | 172-174 °C (lit.) |
| Boiling point | 287 °C |
| Density | 1.33 g/cm³ |
| Vapor density | 3.8 (vs air) |
| Refractive index | 1.632 |
| Storage temp | Store below +25°C, keep away from light and air |
| Solubility | Water: 70 g/L (25°C); freely soluble in ethanol, acetone, ether; sparingly soluble in benzene |
| Form | Crystalline solid |
| Color | White to off-white, darkens on exposure |
| Odor | Odorless |
| PH Range | 5.5 - 6.5 (aqueous solution) |
| Sensitive | Light & Air Sensitive |
| Merck | 14,4808 |
| BRN | 605970 |
| Stability | Stable under recommended storage conditions. Incompatible with strong oxidizing agents, strong bases. |
| InChIKey | QIGBRXMKCJKVMJ-UHFFFAOYSA-N |
| CAS DataBase Reference | 123-31-9 (CAS DataBase Reference) |
| NIST Chemistry Reference | Hydroquinone (123-31-9) |
| EPA Substance Registry System | 1,4-Benzenediol (123-31-9) |
| Safety Information | |
|---|---|
| Hazard Codes | Xn |
| Risk Statements | 22-36/37/38-43-68-50/53 |
| Safety Statements | 26-36/37-46-61 |
| WGK Germany | 3 |
| RTECS | MX3500000 |
| F | 8 |
| TSCA | Yes |
| HS Code | 29072200 |
This compound is widely used as a polymerization inhibitor in monomer production, an antioxidant for lubricants and rubber products. It acts as a black-and-white photographic developer in imaging industry, and a core intermediate for manufacturing azo dyes and anthraquinone dyes. It also works as a reducing agent for metal analysis, raw material for pharmaceutical and agrochemical synthesis, as well as additive for coatings and adhesives to avoid oxidative degradation.
