1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Peroxide's cool

  1. Feb 21, 2005 #1

    DaveC426913

    User Avatar
    Gold Member

    Been using [tex]H_2 O_2[/tex] to sterilize a wound. I notice that it fizzes.

    1] I presume the bubbles it releases are [tex]O_2[/tex]. i.e. [tex]2 H_2 O_2 > 2H_2 O + O_2[/tex]
    2] I further presume it is the [tex]O_2[/tex] that kills the bacteria.

    And that makes me wonder:
    3] I notice that it only fizzes on my wound - it does not fizz when applied to normal skin (or the container it comes in, or the Q-tip). Although it does fizz when poured into the drain. It seems to zero in on organic material.

    I am guessing this is because:
    - my skin has an oily (i.e. water repellant) coating that the peroxide can't react on/with, or
    - the wound has chemically active components that normal skin will not expose, or
    - the wound has physically reactive components - like the miscroscopic nicks in a champagne glass that serve as bubble nurseries (I forget the name)

    4] Also, why does it not spontaneously revert to water in the bottle? Even over a long time?


    Thoughts?
     
  2. jcsd
  3. Feb 21, 2005 #2

    dextercioby

    User Avatar
    Science Advisor
    Homework Helper

    1.Yes,the reaction u've discribed is incorrect...The correct redox is:

    [tex] H_{2}O_{2}\rightarrow H_{2}O+O [/tex]

    which means the one atom gets reduced and another oxydated...Note that atomic oxygen is the powerful oxydating agent...So not [itex] O_{2} [/itex] kills bateria (it would be ridiculous,why need hydrogen peroxyde,then),but atomic oxygen...

    Daniel.
     
  4. Feb 21, 2005 #3

    GCT

    User Avatar
    Science Advisor
    Homework Helper

  5. Feb 21, 2005 #4

    DaveC426913

    User Avatar
    Gold Member

    Thank you. I don't think I could have gotten a more comprehensive answer if I'd written the question after reading the answer!

    P.S. dexter: you might want to read it too. It specifies pretty much the exact reaction I did:

    H2O2 --> H2O + O2

    (I think your and their answer are ultimately equivalent, you are just concentrating on a discrete intermediate step).
     
  6. Feb 21, 2005 #5
    no actually your equation isn't balanced making it wrong. It is a two step reaction as oxygen isn't going to stick around in its monatomic form for long but if it was immediately just diatomic then the air would be as good a bacteriocide as hydrogen peroxide.
     
    Last edited: Feb 21, 2005
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Peroxide's cool
  1. Lipid peroxidation (Replies: 1)

  2. Hydrogen Peroxide (Replies: 12)

  3. Hydrogen Peroxide (Replies: 6)

  4. Hydrogen Peroxide (Replies: 12)

Loading...