Hydrogen peroxide

Hydrogen peroxide

Names
IUPAC name hydrogen peroxide
Other names Dioxidane Oxidanyl Perhydroxic acid
Identifiers
CAS Number	7722-84-1 Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:16240 Y
ChEMBL	ChEMBL71595 Y
ChemSpider	763 Y
ECHA InfoCard	100.028.878
EC Number	231-765-0
IUPHAR/BPS	2448
KEGG	D00008 Y
PubChem	784
RTECS number	MX0900000 (>90% soln.) MX0887000 (>30% soln.)
UNII	BBX060AN9V Y
UN number	2015 (>60% soln.) 2014 (20–60% soln.) 2984 (8–20% soln.)
InChI InChI=1S/H2O2/c1-2/h1-2H Y Key: MHAJPDPJQMAIIY-UHFFFAOYSA-N Y InChI=1/H2O2/c1-2/h1-2H Key: MHAJPDPJQMAIIY-UHFFFAOYAL
SMILES OO
Properties
Chemical formula	H2O2
Molar mass	34.0147 g/mol
Appearance	Very light blue color; colorless in solution
Odor	slightly sharp
Density	1.11 g/cm3 (20 °C, 30% (w/w) solution ) 1.450 g/cm3 (20 °C, pure)
Melting point	−0.43 °C (31.23 °F; 272.72 K)
Boiling point	150.2 °C (302.4 °F; 423.3 K) (decomposes)
Solubility in water	Miscible
Solubility	soluble in ether, alcohol insoluble in petroleum ether
Vapor pressure	5 mmHg (30 °C)
Acidity (pKa)	11.75
Magnetic susceptibility (χ)	−17.7·10−6 cm3/mol
Refractive index (nD)	1.4061
Viscosity	1.245 cP (20 °C)
Dipole moment	2.26 D
Thermochemistry
Specific heat capacity (C)	1.267 J/(g·K) (gas) 2.619 J/(g·K) (liquid)
Std enthalpy of formation (ΔfHo298)	−187.80 kJ/mol
Pharmacology
ATC code	A01AB02 (WHO) D08AX01 (WHO), S02AA06 (WHO)
Hazards
Safety data sheet	ICSC 0164 (>60% soln.)
EU classification (DSD)	Oxidant (O) Corrosive (C) Harmful (Xn)
R-phrases	R5, R8, R20/22, R35
S-phrases	(S1/2), S17, S26, S28, S36/37/39, S45
NFPA 704	0 3 2 OX
Flash point	Non-flammable
Lethal dose or concentration (LD, LC):
LD50 (median dose)	1518 mg/kg 2000 mg/kg (oral, mouse)
LC50 (median concentration)	1418 ppm (rat, 4 hr)
LCLo (lowest published)	227 ppm (mouse)
US health exposure limits (NIOSH):
PEL (Permissible)	TWA 1 ppm (1.4 mg/m3)
REL (Recommended)	TWA 1 ppm (1.4 mg/m3)
IDLH (Immediate danger)	75 ppm
Related compounds
Related compounds	Water Ozone Hydrazine Hydrogen disulfide Dioxygen difluoride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

Hydrogen peroxide is a chemical compound with the formula H
2O
2. In its pure form, it is a colourless liquid, slightly more viscous than water. Hydrogen peroxide is the simplest peroxide (a compound with an oxygen–oxygen single bond). It is used as an oxidizer, bleaching agent and disinfectant. Concentrated hydrogen peroxide, or "high-test peroxide", is a reactive oxygen species and has been used as a propellant in rocketry. Its chemistry is dominated by the nature of its unstable peroxide bond.

Hydrogen peroxide is unstable and slowly decomposes in the presence of base or a catalyst. Because of its instability, hydrogen peroxide is typically stored with a stabilizer in a weakly acidic solution. Hydrogen peroxide is found in biological systems including the human body. Enzymes that use or decompose hydrogen peroxide are classified as peroxidases.

The boiling point of H
2O
2 has been extrapolated as being 150.2 °C, approximately 50 °C higher than water. In practice hydrogen peroxide will undergo potentially explosive thermal decomposition if heated to this temperature. It may be safely distilled at lower temperatures under reduced pressure.

In aqueous solutions hydrogen peroxide differs from the pure material due to the effects of hydrogen bonding between water and hydrogen peroxide molecules. Hydrogen peroxide and water form a eutectic mixture, exhibiting freezing-point depression; pure water has a melting point of 0 °C and pure hydrogen peroxide of −0.43 °C, but a 50% (by volume) solution of the two freezes at −51 °C. The boiling point of the same mixtures is also depressed in relation with the mean of both boiling points (125.1 °C). It occurs at 114 °C. This boiling point is 14 °C greater than that of pure water and 36.2 °C less than that of pure hydrogen peroxide.