I am a chemistry student and having trouble comprehending mols. One of my homework/study questions is as follows:

"How many zinc ions are present in 30.5g of Zn2 P2 O7 ?"

I have tried to work out the answer and cannot figure out how do to do it.

Thanks!

Avogadro constant - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Avogadro_constant)
Mole (unit) - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Mole_%28unit%29)

Avogadro's Number is the number of molecules in a mole. One mole of a compound has a mass of <amu> grams. (eg. 1 mole of carbon-12 has a mass of 12 grams)

What you need to do is determine the mass of the specified molecule. Then determine how many moles that is. Next step is to determine the number of Zn ions in that. (be careful of the possible "gotta" in the molecular formula)