Notices
Results 1 to 4 of 4

Thread: Hydrogen peroxide

  1. #1 Hydrogen peroxide 
    New Member
    Join Date
    Sep 2007
    Posts
    3
    when manganese dioxide is added as a catalyst to speed up the production of oxygen, what are the chemical equations?


    Reply With Quote  
     

  2.  
     

  3. #2  
    Suspended
    Join Date
    Apr 2007
    Location
    Pennsylvania
    Posts
    8,795
    * Manganese dioxide also catalyses the decomposition of hydrogen peroxide to oxygen and water.

    2 H2O2(aq) → O2(g) + 2 H2O(l)
    http://en.wikipedia.org/wiki/Manganese_dioxide


    Reply With Quote  
     

  4. #3  
    New Member
    Join Date
    Sep 2007
    Posts
    3
    Ya, I saw that on wikipedia, too, but how does Manganese dioxide speed it up?
    Reply With Quote  
     

  5. #4  
    Forum Sophomore Matt Lacey's Avatar
    Join Date
    Sep 2006
    Location
    Southampton, England
    Posts
    119
    It's basically a redox reaction

    H<sub>2</sub>O <=> H<sub>2</sub>O<sub>2</sub> + 2e<sup>-</sup>

    H<sub>2</sub>O<sub>2</sub> <=> O<sub>2</sub> + 2e<sup>-</sup>

    Transition metals can accept and donate electrons to switch between oxidation states (like Mn(IV) in this case) and so they undergo and catalyse a lot of redox reactions.

    I don't know the mechanism offhand but it's just a load of electrons being swapped around because in terms of oxidation states, hydrogen peroxide (-1) is the intermediate between water (-2) and oxygen (0). Manganese dioxide just gets involved and speeds up the process, regenerating itself in the process.

    Hope that helps
    Reply With Quote  
     

Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •