Question

The formula for dinitrogen monoxide is n2o. if a sample of the oxide was found to contain 0.0800 g of oxygen, how many grams of nitrogen would it contain?

Answer 1

The formula for dinitrogen monoxide is N₂O
this means that the number of moles of N to O is 2:1 in the compound.
the number of O moles is 0.0800 g / 16 g/mol = 0.005 mol 
therefore number of N moles is - 0.005 x 2 = 0.01 mol
molar mass of N - 14 g/mol 
then mass of N it contains is - 0.01 mol x 14 g/mol = 0.14 g