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Chemistry help please

  1. Sep 13, 2005 #1
    I have a chemistry assignment question that I don't understand. Any help you could give me as ot solving this problem would be greatly appreciated. Here is the question:
    Suppose you make a solution that contains 10.23g of sodium chloride and 629g of water
    a)what is the mass%of sodium chloride
    b)If 11.72ml of your solution weighs 11.833g what is the density.

    I should know how to do this problem but I havent' taken chemistry for 2 years
  2. jcsd
  3. Sep 13, 2005 #2


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    Staff Emeritus
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    Mass % = mass of consituent (in this case NaCl) / total mass x 100.

    Total mass = mass NaCl + mass water.

    Density = mass / vol.

    Units of density could be kg/l (l = liter), kg/m3, g/cc (cc = cm3), or g/ml, as well as others.
  4. Sep 13, 2005 #3
    I understand A but I still don't understand how to do B
  5. Sep 13, 2005 #4
    density = Mass/Volume

    you have mass..now you need volume..as in astronuc posts there can be many density units.
    there is a conversion from milliliter to gram or kg. So you gotta find out how to do that conversion...simple steps of changing the metric/measurement unit..
    like a conversion from yards to m.
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