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Cold Fog?

  1. Mar 18, 2007 #1
    This week a coworker and i were killing time between smoke breaks talking about alternative energy, hydrogen fuel cells and what not.

    He started telling me about some electrical proccess that could cause an explosive expansion of water without much heat. he told me a electrical spark delivered in a sertain manner could cause water molecules to push violently apart from each other.

    The water dosent vaporise from the heat of the spark but the molecules separate at the hydrogen bond? i guess . it dint click for me but i have no training in physics other than watching Bill nye as a kid. the thing that stands out for me is the heat, i thought that if the water molecules moved away so fast there would just be heat from molecular motion.

    The other thing was he told me that the (kenitic) energy released by the shocked water was greater than what it took to spark it up. im failry sure this is a load of C. i just dont know how to show it and i cant find anything online about it. even withouththe magic energy gain id like to see water do something ive never seen before.

    Does anyone know about this stuff?:tongue2: id realy liek to squash this before hes got us all building pyramid power hats in the office.

    EDIT: thanks for reading my post i still want to know if water can pop like my friend describes i understand that there is probly no energy gain. he probly wouldnt be conviced by the conservation of energy rule because he belives that there is an unseen contributor to the equasion that stores/releases the extra energy, i suggested the easter bunny but he didnt comment on it.
    Last edited: Mar 19, 2007
  2. jcsd
  3. Mar 18, 2007 #2
    Look up conservation of energy. What he is talking about is a variation of the perpetual motion machine. The reality is that it always takes more energy to break the bonds in water than you get out in energy content of the H2.

    (Now the pyramid power hats on the other hand, I have heard they really work!! -- just joking)
  4. Mar 20, 2007 #3
    so can water pop or what?

    Thanks for replying to my post i still would like to know if water can behave as my friend described . :approve:
  5. Mar 21, 2007 #4
    Well, interested_learner stated that your friend has in mind something like a perpetual motion machine. These are forbidden by the Second Law of Thermodynamics. So, no. Your friend's machine won't work.

    It sounds as if you would get more work out of the process than energy you drew from your reservoir. Of course you were right in thinking it was bull. I don't know what the numbers would be; but it sounds like this would violate the First Law too.

    In terms of the water not evaporating — what happens is that when water hits it's phase change temperature, ALL of the energy put into it goes into dissolving those bonds keeping it together. Once that is done, only then can the temperature go up.

    (keep in mind, I'm only a college freshman who just got done with Thermodynamics. Correct me, please, if I've made an error somewhere!)
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