What is the empirical formula of a compound that contains 30.4% nitrogen and 69.6% oxygen by mass?

1 Answer
May 27, 2017

Answer:

#NO_2#..........

Explanation:

AS is typical in these problems, we ASSUME an #100*g# mass of unknown compound, and we divide thru by the atomic mass:

#"Moles of nitrogen"=(30.4*g)/(14.01*g*mol^-1)=2.17*mol.#

#"Moles of oxygen"=(69.6*g)/(15.999*g*mol^-1)=4.35*mol.#

And we divide thru by the SMALLEST molar quantity to get an empirical formula of #NO_2#...........