LeChatlier's Principle for changes in temperature?...

Discussion in 'General Discussions' started by lazypando, Mar 22, 2007.

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  1. lazypando

    lazypando Level IV

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    and anyone explain LeChatlier's Principle for changes in temperature?...I'm a bit confused :p
     
  2. chrisw2525

    chrisw2525 Level IV

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    There are 3 boxes side-by-side. If the first boxes mass is 15kg, the second box 12kg and the third 13.5kg. If they are pushed with a force of 450N what is the force on the first box from the second box?
     
  3. rapidah

    rapidah Level III

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    since the boxes are stationary, the only force thats acting on the second box is gravity
    g=9.8
    F=mg
    F=12kg*9.8
    force acting on the first box=117.6N
    120N if u need sig figs
    (think this should be right but i was never that good at physics)
     
  4. Angelika

    Angelika Moderator

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    Just in general?

    Well, say you had an exothermic reaction. If you were to lower the temperature, the equilibrium would shift so that more heat was being produced. And vice versa. So if you lowered the temperature on the reactant side, the equilibrium would shift to the right to produce more heat. So, Le Chatelier says that when a system at equlibrium experiences a change in temp, conc., etc (you probably know this), the equilibrium shifts to minimize the effects of that change, so it's basically logic.

    I can help if you'd like. :)
     
  5. lazypando

    lazypando Level IV

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    thanks :p

    we did a lab today demonstrating the principle...it was spiffy :D
     
  6. Karuken

    Karuken Level I

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    LaChatelier's Principle: If a system at equilibrium is subjected to a stress, it will shift to relieve that stress.
    --I'm assuming you know that....
    Reactants (<)---> Products

    Basically, the concentration of the substances on the same side of the increase in temperature will decrease , while the concentration of the substances on the opposite side will increase.

    I'm assuming you're doing Chemistry, we did this very recently in class and what I got out of it is...
    -------------------------------------------------------------------
    (Assume that anything before the substance is the coefficient and anything after is a subscript)

    Example:

    CH4 + 2O2 <----> CO2 + 2H2O + Heat (rise in temp)

    -An Increase in temperature on the product's side indicates an Exothermic reaction because there is excess heat after the reaction is complete.

    -------------
    As temperature increases, the concentration of:
    -[O2] Increases
    -[CH4] Increases
    (while) Shifts Left
    -[CO2] Decreases
    -[2H2O Decreases
    -------------
    (and)
    -------------
    As temperature decreases, the concentration of:
    -[O2] Decreases
    -[CH4] Decreases
    (while) Shifts Right
    -[CO2] Increases
    -[2H2O Increases
    -------------

    If you don't need all of the information, sorry. I just wanted to be really clear. In essence, the same side of the increase goes down, opposite side goes up. The reaction shifts to whatever side increased...

    Hope this answered your question!

    Edit: Also, a change in temperature is the only change (from among concentration, pressure and temperature) that affects the Keq, or Constant Equilibrium

    Edit: No, I didn't c/p this from anywhere...I am working on a huge project and I took 15-20 minutes to type this to get my mind away from American artistes and ... blah. How nerdy is this? Really efking nerdy.
     
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