# Hot Water

1. Dec 8, 2004

### dajugganaut

"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. Dec 9, 2004

### chem_tr

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 $\displaystyle 1.3\times 10^{18}~m^3$. 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