Consider separate 100.0-g samples of each of the following: nh3, n2o, hcn, n2h4, and hno3. which of the samples has the greatest mass of nitrogen?

To find out which sample has the greatest mass of nitrogen, we must find of the nitrogen concentration of each molecule first.

Concentration of N = Molar mass of N/molecular weight

So,

Conc. of N in NH3 = 14 / (14+3*1) = 82.4%

Conc. of N in N2O = (14*2) / (14*2+16) = 63.6%

Conc. of N in HCN = 14 / (1+12+14) = 51.9%

Conc. of N in N2H4 = (14*2) / (14*2+4*1) = 87.5%

Conc. of N in HNO3 = 14 / (1+14+16*3) = 22.2%

So in 100 g sample of each molecule, the mass of N is 82.4 g in NH3, 63.6 g in N2O, 51.9 g in HCN, 87.5 g in N2H4, 22.2 g in HNO3, respectively.

Therefore, N2H4 has the greatest mass of nitrogen.