Question

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

Answer 1

`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`...........