# Question 876a6

Mar 16, 2017

The formula is ${\text{XY"_2"ZX}}_{4}$.

#### Explanation:

We must determine the relative number of moles of each element.

$\text{Moles of x" = "0.025 mol}$

$\text{Moles of Y" = 3.0 × 10^22 color(red)(cancel(color(black)("atoms"))) × "1 mol"/(6.022 × 10^23 color(red)(cancel(color(black)("atoms")))) = "0.050 mol}$

$\text{Moles of Z" = 3.2 color(red)(cancel(color(black)("g"))) × "1 mol"/(32 color(red)(cancel(color(black)("g")))) = "0.10 mol}$

Now, we find the molar ratio of $\text{X:Y:Z}$.

We divide each number of moles by the smallest number ($\text{0.025 mol}$) and convert them to integers.

"X:Y:Z" = 0.025/0.025:0.050/0.025:0.10/0.025 = 1:2.0:4.0 ≈ 1:2:4#

The molecular formula is ${\text{XY"_2"Z}}_{4.}$