Relative Atomic mass of compound xy?

Question

you have 2 distinct gaseous compunds made from elements x and y:
compund 1: 30.43%x, 69.57%y
compund 2: 63.64%x, 36.36%y

when you react gas x with y, you get:
1 volume gas x + 2 volumes gas y -> 2 volumes compund 1

2 volumes gas x + 1 volume gas y -> 2 volumes compund 2

Assume simplest possible formula and determine relative atomic masses of element x and element y.

i don't understand how to incorporate the percents.

Answer 1

First let us note X with sub 2 as X2.
The gases may be approximated as ideal gas, such that the volume is proportional to the number of moles. Hence from:
1 volume gas x + 2 volumes gas y -> 2 volumes compund 1
2 volumes gas x + 1 volume gas y -> 2 volumes compund 2
we may conclude that pure gas x must be diatomic and can be written as X2, and gas y must also be diatomic and can be written as Y2, since there are not any X4 or X6 gases.
The compund 1 must be triatomic gas and can be written as XY2. The compund 2 must also be triatomic gas and can be written as X2Y.
Now consider compund 1 with empirical formula XY2: 30.43%x, 69.57%y. Since both x and y are diatomic molecules and compund 1 contains one atom of X and 2 atoms of Y, the X-Y mass ratio must be: 30.43 : (69.57/2) = 30.43 : 34.79.
Similarly consider compund 2, we can conclude that the X-Y mass ratio must be: (63.64/2) : 36.36 = 31.82 : 36.36.
We trust 30.43 : 34.79 ≈ 31.82 : 36.36 with sufficient accuracy. Indead, the ratio is 0.875. Since the atomic mass of X and Y must be integer or very close to integer (due to isotopic effect), and the ratio is 0.875 = (atomic mass of X)/(atomic mass of Y), 0.875*(atomic mass of Y) must also be integer or very close to integer. The smallest possible atomic mass of Y is found to be 8, but there is no such element. The second possible atomic mass of Y is found to be 16, which is oxygen. The corresponding atomic mass of X is 14, which is nitrogen.
So the solutions are:
x is N2, y is O2, compund 1 is NO2, compund 2 is N2O, the atomic mass of N is 14 and the atomic mass of O is 16.

Answer 2

you pick for the final formula for the component first. as an occasion H2O is water and its relative atomic mass would be including up all the atomic numbers of the present factors via finding on the periodic table. so as a result the RAM would be (one million x 2) + sixteen=18