How many atoms are in 10g of water?

Answer 1

Each water molecule contains exactly 3 atoms, as shown by its chemical formula, H2O. The gram molecular mass of water is 18.01528. Therefore, the number of atoms in 10 g of water is 3 (10/18.01528)(Avogadro's Number), or 1.0 X 1024, to the justified number of significant digits.

Answer 2

To do this, you need to know the molecular weight of the element you're dealing with, by adding up the atomic weights of the elements involved (found on any Periodic Table). The molecular weight is the mass in grams of the compound in one mole - this will provide you with a conversion factor. So take the measurement in grams and divide it by the molecular weight to convert to moles. Really what you're doing is multiplying the number by 1 mole, and dividing it by the equivalent of one mole, the molecular weight. That's the thought process behind unit analysis and how you get your "units to cancel".
In this case, the answer is about .0611 moles water.

Answer 3

10/18=5/9 moles=.555 moles