N,N-Dimethylformamide
High Reactivity: Hydroquinone exhibits significant chemical reactivity, participating in various transformations including oxidation, esterification, and substitution reactions, which supports its utility across multiple industrial processes.
Solubility: It demonstrates ready solubility in hot water, ethanol, and diethyl ether, providing formulation flexibility across different solvent systems.
Stable Under Control: While sensitive to oxidative degradation when exposed to air and light, it remains chemically stable over extended periods when stored under appropriate dark and airtight conditions.
Industrial Use: It serves critical functions as a stabilizing agent and antioxidant in industrial sectors including pharmaceutical synthesis, cosmetic formulations, and photographic development.
Hydroquinone (C₆H₆O₂, MW 110.11), systematically named 1,4-benzenediol, typically presents as white needle-like crystals that undergo progressive darkening upon atmospheric exposure due to oxidation. Its aqueous solutions oxidize spontaneously in air, developing a brown coloration—a process markedly accelerated under alkaline conditions.
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 |
The compound demonstrates characteristic physical constants with a melting point of 170–171°C, boiling point of 285–287°C, and density of 1.332 g/cm³. Spectral analysis reveals maximum UV absorption at 288 nm in aqueous medium. It shows high solubility in hot water, ethanol, and diethyl ether, but limited dissolution in benzene. Chemically, hydroquinone exhibits significant reactivity, undergoing facile oxidation and participating in characteristic reactions including esterification and electrophilic substitution.
