Help Please: CHE

Question

Suppose there are two known compounds containing the generic elements X and Y. You have a 1.00 g sample of each compound. One sample contains 0.27 g of X and the other contains 0.36 g of X.

Identify plausible sets of formulas for these two compounds.

XY and X₂Y

X₄Y₂ and X₃Y

X₂Y₂ and X₃Y₂

XY and X₃Y

X₃Y and X₄Y

XY₃ and XY₄

X₂Y and X₃Y

Answer 1

Take the ratio of masses:

In compound 1, you have 0.27 g X and 0.73 g of Y. The ratio of X:Y = 1 : 2.7

In compound 2, you have 0.36 g X and 0.64 g of Y. The ration of X:Y = 1 : 1.77

Let's say we have compounds with 8 g of Y

Compound 1 will have 3 g X and 8 g of Y (ratio 1 : 2.7)

Compound 2 will have 4.5 g X and 8 g of Y (ratio 1 : 1.77)

The ratio of masses of X in the 2 compounds is 3 : 4.5 = 1 : 1.5 = 2 : 3 whole numbers

So, we would have a fixed whole number ratio of moles of X : Y of 2 : 3

So, the ratio of MOLES OF X with a fixed mass of Y is 2 : 3

The following would fit this scenario:

X₄Y₂ and X₃Y

X₂Y and X₃Y

X₂Y₂ and X₃Y₂