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chem question

Discussion in 'MCAT Study Question Q&A' started by mR LaZy, Dec 18, 2008.

  1. mR LaZy

    mR LaZy Member
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    how much CO2 is produced @stp from 100ml of solution made by mixing 100g of KHCO3 into enough solution to form 500ml?

    rxn eq = HBr+KHCO3 -> KBr +h2o + co2

    thanks
     
  2. mR LaZy

    mR LaZy Member
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    i think i solved it

    100g x 1mole khco3/95g = 1.05 moles/.5L = 2 x .1L x [email protected] = 4.48L of CO2

    anyone have any suggestions?
     
  3. ksmi117

    ksmi117 GEAUX TIGERS!!!
    Physician Moderator Emeritus Lifetime Donor Classifieds Approved 7+ Year Member

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    looks good to me :)
     
  4. w0lf137

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    To save some time (skipping the concentration part of the equation), because 1 mole of khco3 will break down to 1 mole of CO2 = 22.4L. That 22.4L is reduced by a 1/5 when the dude takes 100ml out of the 500 ml. In other words the 1 mole of CO2 in the 500 mL is reduced to a certain # of moles in the 100mL. Going from 500 ---> 100 is 1/5. So reducing the 1 mole or 22.4L (at stp) by a 5th is: 22.4/5 is around 5L.
     

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