in terms of mass, N:O = 14:16 = 7:8
so, 4.2g is 7/15 of the total mass
see what you can do with that
A 13.8 g sample of a compound containing only N and O produced 4.2 g of nitrogen on decomposition. What is its empirical formula? What is its molecular formula if the molar mass of the compound is 92.0 g/mol
2 answers
4.2 g is N; 9.6 g is O.
g-atom N = 4.2/14 = 0.3
g-atoms O = 9.6/16 = 0.6
ratio is N1O2
So the empirical formula is NO2.
empirical mass is 14 + 16 + 16 = 46
How many of these units does it take to make a molecule if the molecule has a mass of 92. Would that be (NO2) x # units = 92 or
46 x #units = 92 and I would write (NO2)2 or N2O4.
g-atom N = 4.2/14 = 0.3
g-atoms O = 9.6/16 = 0.6
ratio is N1O2
So the empirical formula is NO2.
empirical mass is 14 + 16 + 16 = 46
How many of these units does it take to make a molecule if the molecule has a mass of 92. Would that be (NO2) x # units = 92 or
46 x #units = 92 and I would write (NO2)2 or N2O4.
3 answers