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Potential energy diagram for a nuclear reaction

  1. Sep 23, 2009 #1
    Saw this on a test question today, it asked if you had 1 mole of reactant (don't know what kind of reactant though...), what would the nuclear reaction potential energy diagram look (don't know if its fusion or fission or exothermic or endothermic it just said nuclear reaction...)? (The reaction progress vs. potential energy diagram that compares energy of reactant and product)

    Its multiple choice since I can't really draw, I'll describe it I'll try to draw tho

    a) shows that the reaction is exothermic with potential change of 550kj, two horizontal (slope is 0) lines that looks something like this


    b) shows the reaction is exothermic with Energy change of 2.2x10^22KJ (I have no idea where my teacher gets these data lol) that looks like the "graph" above but just more energy released

    c) shows the reaction is endothermic with energy change of 550kj


    d) shows the reaction is exothermic with energy change of 2.2x10^22KJ

    The graph for d is less slant (with like a slope of 1 or something)

    I chose d) for the answer cus it doesn't make sense to me how 20 times the energy of a strong earth quake could be released in an instant =/

    EDIT: ok uhh the "diagram" isn't showing up right lol, I made it a lot smaller...
  2. jcsd
  3. Sep 24, 2009 #2
    Do you really not konw what the reaction is and you have to say what the potential energy diagram looks like?

    Nuclear reactions that are endothermic involve shooting atoms at each other at high speeds.

    2.2*10^22 KJ is far more energy than could be produced by any nuclear reaction from a mole of stuff, including converting the entire mass to energy. you can only get [itex] E = mc^2 [/itex] of energy.
    m < 1kg and c^2 is only 9*10^17, so E < 9*10^17 J

    550 KJ/mole is a very small energy for a nuclear reaction. Most chemical reactions produce more energy.
  4. Sep 24, 2009 #3
    well I remember the test, and its crystal clear in my mind

    The numbers aren't wrong... I didn't think it made sense but I guessed that nuclear reaction would be more energetic than just 500kj lol

    And there was no given equation or quantity at all just 1 mole, and it tells that its a nuclear reaction lol

    Do you think this is bad question?
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