Chapter 1, Problem 69CP

You have two distinct gaseous compounds made from element X and element Y. The mass percents are as follows:

Compound I: 30.43% X, 69.57% Y

Compound II: 63.64% X, 36.36% Y

In their natural standard states, element X and element Y exist as gases. (Monatomic? Diatomic? Triatomic? That is for you to determine.) When you react “gas X” with “gas Y” to make the products, you get the following data (all at the same pressure and temperature):

1. volume “gas X” + 2 volumes “gas Y→2 volumes compound I

2. volumes “gas X” + 1 volume “gas Y”→2 volumes compound II

Assume the simplest possible formulas for reactants and products in the chemical equations above. Then, determine the relative atomic masses of element X and element Y.