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  1. alright, thank you
  2. oh ok thanks! so does this also mean that MnO2 will not be present in the rate determining step?
  3. Hi I was hoping you could help me with the following question. I've been struggling with it for ages and need to figure it out asap as its due in on Friday.

    At school i've had to do a chemistry investigation on catalytic decomposition of hydrogen peroxide using MnO2 as catalyst.
    As one part of my investigation, I varied the amount of catalyst I used (0.25g, 0.5g, 0.75g, 1g and 1.5g), I kept the H2O2 concentration constant at 2.5 vols and room temperature. I collected O2 gas for 2 mins, and measured at every 15 second intervals.
    I also investigated change in concentration of H2O2 on reaction rate and found it to be first order.

    so how do I work out the order for MnO2, as it is used as a solid???

    rate = k[H2O2]^1*[MnO2]^?

    or do i not include it in the rate equation at all??

    Thanks in advance
  4. Oh right I see, do you anyone who is a bio mod, who would be able to merge them in the order i stated?

    Btw thanks!
  5. Hi,

    Can you merge these 2 threads into my one as I have more resources available please.

    Those 2 above into this one:

  6. Quick question. I was wondering how ka changes with temperature. I know Kw increases with temperature since the dissociation of water is endothermic in the forwards direction. I was thinking that acid dissociation would also be endothermic since energy is being inputted in order to break the bonds but I saw something online and it says that most acid dissocaition reactions are exothermic (don't understand why that would be though). To summarise, I am wodnering if you could tell me whether acid dissociaiton is endothermic or exothermic in the forwards direction and if it is exothermic why that is. Many thanks!
  7. Hey Charco
    super super quick question about making haloalkane from an alcohol

    I've learnt that to go from alcohol to alkene we dehydrate and use conc sulfuric acid. I notice that 'godofgod' did the dehydration with phoshporic acid. Is it okay to do exactly what he has said but using conc sulfuric acid instead of phosphoric?
  8. please helpppppppppp
  9. Hi Charco,

    Can you please have a look at my thread and see if perhaps you may be able to help?
  10. hey um is it ok if i post multiple questions on the physics forum at a time?

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  • Last Activity 21 hours ago
  • Join Date 15-02-2005

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Join Date 15-02-2005

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