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Homework Help: Calculating mass of reactanrs

  1. Feb 2, 2009 #1
    I have this lab in class, and i have not done chemsitry for a while..Can anyone help me with this...much thankful

    purpose: To determine the mass of percipitate produced when 10ml of 0.20 mol/L carbonate reacts with 20 ml of 0.225 mol/L calcium chloride..

    For the procedure i think i am ok

    but the calculation is where i have no idea how to start..
    any help would be helpful

    thank you
     
  2. jcsd
  3. Feb 2, 2009 #2

    chemisttree

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    Start with the precipitation reaction and then use the solubility product.
     
  4. Feb 3, 2009 #3

    thank you for the reply..but I am still confused..i balanced out the equation which is
    CaCl(2)(aq)+ Na(2)CO3(aq)-----> Ca(CO3)(l)+2NaCl(aq)

    and then the moler mass are:
    1) 10ml of 0.20 mol/l sodium carbonate is 0.01*0.20=0.002
    2) 20ml of 0,225 mol/l calcium chloride is 0.020*0.225=0.0045


    and the mass of the participate is 2.82g -2.60g(mass of the filter) = .72g

    but now i have no idea where to go...i know i have to do stoichiometry but i am so confusedd

    Plz anyone help
     
  5. Feb 6, 2009 #4

    chemisttree

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    Now, what is the solubility product for CaCO3?

    Correction: Your equation should be

    CaCl(2)(aq)+ Na(2)CO3(aq)-----> Ca(CO3)(s)+2NaCl(aq)
     
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