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Concenctration of a mass

  1. Dec 6, 2009 #1
    Hi guys,here is my question. What is the Concentration of Na2CO3 when it dissolves in a solution and forms a volume of 100 cubic cm?

    Concentration= moles/volume.
    I found moles using mass/atomic mass of Na2+C+03.
    Then i used moles/volume to calculate concentration. Correct?
  2. jcsd
  3. Dec 6, 2009 #2
    Mass of Na2CO3 is 5.8g
  4. Dec 6, 2009 #3
    So far so good.
  5. Dec 6, 2009 #4
    I found concentration to be 0.0005M. Could you confirm if this is correct?
  6. Dec 6, 2009 #5
    Sounds a bit low to me, can you show your working?
  7. Dec 6, 2009 #6

    Moles = mass/atomic mass, 5.8g/Na2C03

    So 5.8/106=0.005moles.

    Conc=0.05/100=0.0005M. So?
  8. Dec 6, 2009 #7
    What is the definition of M here?
  9. Dec 6, 2009 #8
    M is concentration. There are two ways of writing it,M or mol/dm3
  10. Dec 6, 2009 #9
    OK, so how many dm3 are there in your solution?
  11. Dec 6, 2009 #10
  12. Dec 6, 2009 #11

    Char. Limit

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    Gold Member

    No... what you'd get in your calculations is 0.0005 mol/cm^3. You should change your mL (cm^3) to L (dm^3) before using it.
  13. Dec 7, 2009 #12


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    Staff: Mentor

    sjb asked about volume of the solution, and you have answered giving concentration...

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