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Hot Water

  1. Dec 8, 2004 #1
    "Hot" Water

    I have this problem in class that I could not solve. Could some one please help me?

    I have 100mL of water made with tritium (radioactive isotope of hydrogen). If I were to pour this 100mL of hot water into the ocean (given the volume of the ocean is 1.3*(10^18)m^3) how many molcecules of the original 100mL of ditritium monoxide would be in a 100mL sample of the ocean water. Assume the tritium oxide has mixed thoroughly.

    As this question deals with grams and molecules, I expect it to have something to do with avogadro's constant. Please suggest a few steps so that I can solve the problem. Thanks!
  2. jcsd
  3. Dec 9, 2004 #2


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    Gold Member

    This is very easy man, just find that 100 mL of ditritium monoxide gives x moles, and this radioactive chemical is dissolved in a solvent, whose volume is [itex]\displaystyle 1.3\times 10^{18}~m^3[/itex]. The cubic meters will cause you a trouble, but concentration can still be calculated from this; for example, it gives us the same result if we calculate millimoles over milliliters, moles over liters, or, just in our case, kilomoles over kiloliters (=one kiloliter is exactly one cubic meter, since one liter is one cubic decimeter).

    I hope this makes sense.
    Last edited: Dec 9, 2004
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