Hydrogen peroxide

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Hydrogen peroxide
Chemical formula H2O2
OTP appearance colorless liquid 
Molar Mass(g/mol) 34 
Melting Point(°C) -0.43 
Boiling Point(°C) 150 
Density(g/cc) 1.135
NFPA 704
NFPA704.png
0
3
2
ox

Uses

Justification Questioned

Other

  • Aids in the production of nitric and sulfuric acids.
  • Combined with sulfuric acid produces pirahna solution useful in metal extraction
  • Rapidly catalyzed decomposition is enormously exothermic and can be used as rocket fuel, etc
  • A potent oxidizer used to convert halide ions to halide molecules
  • Pharm: rapid injection into puncture wounds prevents tetanus.

Natural Occurrence

  • Does occur naturally in very tiny amounts in plants and animals.

Hazards

  • Contact with metals can result in a self-catalyzing decomposition, producing a lot of thermal energy and and abundance of gaseous pxygen: A bad combination.
    2 H2O2
    {Ag
    }
    2 H2O + O2
  • Contact with organics can result in sensitive (primary-explosive) organic peroxides
  • e.g. TATP

Production

Synthesis

Barium Peroxide

hydrochloric acid

This is the most efficient, since dilute acids can be used. Net reaction BaO2 + H2SO4 BaSO4 + H2O2

  1. Combine barium peroxide with hydrochloric acid, giving barium chloride and hydrogen peroxide.
    BaO2 + 2 HCl BaCl2 + H2O2
  2. Distill the hydrogen peroxide, leaving the barium chloride
  3. Add barium chloride to sulfuric acid, precipitating barium sulfate and regenereating the hydrochloric acid
    BaCl + H2SO4 BaSO4 + 2 HCl
phosphoric acid
sulfuric acid

Sodium peroxide

Electrolysis

Electrolysis of a chilled (10°C) acidic (H2SO4) solution of ammonium bisulfate[2] produces ammonium persulfate and hydrogen, which escapes. The persulfate decomposes to hydrogen peroxide and sulfuric acid, which recombines with the ammonium cations to reconstitute the original ammonium bisulfate.

2 NH4HSO4 (NH4)2S2O8 + H2
(NH4)2S2O8 + 2 H2O 2 NH4HSO4 + H2O2
NET: 2 H2O H2O2 + H2

Testing

Purification

  1. Prepare a saturated solution of barium hydroxide
  2. Add dilute hydrogen peroxide, precipitating a stochiometric amount of barium peroxide
    Ba(OH)2 + H2O2 BaO2(s) + 2 H2O
  3. Filter and discard filtrate, retaining the residue of barium peroxide
  4. Add filtrate to concentrated sulfuric acid, producing concentrated hydrogen peroxide and barium sulfate
    BaO2 + H2SO4 BaSO4 + H2O2
    Would hydrogen sulfide work as well?
    BaO2 + H2S BaS + H2O2 // would this work?

Storage

  • It can be "stored" in solid form in percarbonates and perborates and quickly reconstituted by heating.
  • aqueous concentrations below 5% can be stored in normal plastic and glass containers
  • aqueous concentrations of 30% or higher must take great care to exclude metal and organic debris in the container. Metals can catalyze decomposition and organics can form very sensitive (primary explosive) peroxides.

Disposal

See Also

References

  1. Dönges, E. (1963) "Lithium and Sodium Peroxides".
    Handbook of Preparative Inorganic Chemistry 1; pp979. 
  2. US patent 2234908 "Manufacture of hydrogen peroxide", 1937
    Link courtesy Google