To determine the number of molecules we must use Avogadro's relation, which tells us that in one mole of any substance there are 6.022 x10^23 molecules. Therefore, the molecules in 51.2 moles of water will be:
[tex]\begin{gathered} MoleculesH_2O=givenmolH_2O\times\frac{6.022\times10^{23}moleculesH_2O}{1molH_2O} \\ MoleculesH_2O=51.2molH_2O\times\frac{6.022\times10^{23}moleculesH_2O}{1molH_2O}=3.08\times10^{25}moleculesH_2O \end{gathered}[/tex]Answer: In 51.2 moles of water there are 3.08x10^25 molecules
