To determine the number of moles of an element in a given compound, we need to determine, first, the number of moles in the compound. Then, we need to know the chemical formula of the compound. From the ratio of the elements, we can relate the elements to finally obtain the number of moles of a particular element. We do as follows:
Moles N2O = 0.215 g N2O ( 1 mol / 44.02 g ) = 4.88x10^-3 mol N2O
Moles N = 4.88x10^-3 mol N2O ( 2 mol N / 1 mol N2O ) = 9.77x10^-3 mol N
Therefore, there are 9.77x10^23 moles of N in 0.215 g of N2O
