Question #90e5d

1 Answer
Dec 5, 2014

I gave this a go and I got a number close to 50%.

Let us name the two compunds XO_A and XO_B.

We know that the ratio of some element, let us say X, to oxygen in XO_A is 1:0.29.

That is, for every 1g of X we have 0.29g of O_A. (1)

Now, taking into account the oxygen-to-oxygen ratio between XO_A and XO_B is 2:7, we can say that

for every 2g of O_A we have 7g of O_B (2) or, for simplicity, for evey 1g of O_A we get 3.5g of O_B.

Therefore, using (1) and (2), we can say that

for every 1g of X we have 0.29 * 3.5 g = 1.02g O_B for the second coumpound.
An approximately 1:1 ratio of X and O_B in XO_B means that the percent composition of X to XO_B is

percentcomposition = 1/(1+1) *100 = 50%