jess
ok, you were essentially right in your first post, for the purposes of this problem.
pip is right in that there are 6.023*10^23 molecules in a mole, but what you're looking for is that molecular weight, in grams / mole.
So, for Zn = 65.409 g/mol, I2 = 253.81 g/mol, ZnI2 = 319.22 g/mol
All you need to do is multiply/divide your measured masses by the atomic weights to get the moles of each one. Then, assume that the equation looks something like x*Zn + y*I2 => zZnI2.
The moles that you calculated in the first step are essentially those values of x,y, and z....only, you need to normalize them to make it sort of a pretty equation. So, if you divide them all by the smallest value, then your smallest number will now equal 1.000000000. The other values will be normalized against this coefficient.
Hope that helps
