Product Details
Hydroquinone, also known as quinol or 1,4-dihydroxybenzene, has the molecular formula C₆H₆O₂ and a molecular weight of 110.11. It appears as colorless or white crystalline solid that readily discolors when exposed to air and light. Its aqueous solution oxidizes in air to form a brown coloration, with oxidation occurring more rapidly under alkaline conditions.
The compound has a melting point of 170–171 °C, a boiling point of 285–287 °C, a relative density of 1.332 (at 15 °C), and exhibits maximum UV absorption at 288 nm in aqueous solution. It is highly soluble in hot water, ethanol, and diethyl ether, but only sparingly soluble in benzene. Chemically reactive, it is particularly prone to oxidation and can participate in various reactions, including esterification and substitution.
Product Parameter
| Melting point | 172-175 °C(lit.) |
| Boiling point | 285 °C(lit.) |
| density | 1.32 |
| vapor density | 3.81 (vs air) |
| vapor pressure | 1 mm Hg ( 132 °C) |
| refractive index | 1.6320 |
| Fp | 165 °C |
| storage temp. | Store below +30°C. |
| solubility | H2O: 50 mg/mL, clear |
| pka | 10.35(at 20℃) |
| form | Needle-Like Crystals or Crystalline Powder |
| color | White to off-white |
| Odor | odorless |
| Water Solubility | 70 g/L (20 ºC) |
| Sensitive | Air & Light Sensitive |
| Merck | 14,4808 |
| BRN | 605970 |
| Henry's Law Constant | (x 10-9 atm?m3/mol): <2.07 at 20 °C (approximate - calculated from water solubility and vapor pressure) |
| Exposure limits | NIOSH REL: 15-min ceiling 2, IDLH 50; OSHA PEL: TWA 2; ACGIH TLV: TWA 2 (adopted). |
| Stability: | Stable. Combustible. Incompatible with strong oxidizing agents, strong bases, oxygen, ferric salts. Light and air-sensitive. Discolours in air. |
| InChIKey | QIGBRXMKCJKVMJ-UHFFFAOYSA-N |
| LogP | 0.59 at 20℃ |
| CAS DataBase Reference | 123-31-9(CAS DataBase Reference) |
| NIST Chemistry Reference | Hydroquinone(123-31-9) |
| IARC | 3 (Vol. 15, Sup 7, 71) 1999 |
| EPA Substance Registry System | Hydroquinone (123-31-9) |
Safety Information
| Hazard Codes | Xn,N |
| Risk Statements | 22-40-41-43-50-68-R68-R50-R43-R41-R40-R22 |
| Safety Statements | 26-36/37/39-61-S61-S36/37/39-S26 |
| RIDADR | 2662 |
| WGK Germany | 3 |
| RTECS | MX3500000 |
| Autoignition Temperature | 930 °F |
| TSCA | Yes |
| HazardClass | 9 |
| PackingGroup | III |
| HS Code | 29072210 |
| Hazardous Substances Data | 123-31-9(Hazardous Substances Data) |
| Toxicity | LD50 orally in rats: 320 mg/kg (Woodard) |
| IDLA | 50 mg/m3 |
