# Question 932c3

Jun 28, 2017

${X}_{2} {Y}_{3}$

#### Explanation:

Atomic mass of $X$ = 75
Percentage of $X$ = 75.8%
Atomic mass of $Y$ = 16
Percentage of $Y$ = (100-75.8)% = 24.2%

Divide each percentage by the correlating mass:
$X$ - $\frac{{P}_{X}}{{M}_{X}} = \frac{75.8}{75} \approx 1$
$Y$ - $\frac{{P}_{Y}}{{M}_{Y}} = \frac{24.2}{75} \approx 1.5$

The ratio of $X : Y = 1 : 1.5$, but you can't have $\frac{1}{2}$ an atom in a molecule, so the ratio must be doubled so $X : Y = 2 : 3$.

The empirical formula = ${X}_{2} {Y}_{3}$

Proof:
For X - "Percentage of mass composition" = ("Mass contributuon")/("Total mass")*100 = (2(75))/(2(75)+3(16))*100 = 75.7575... =75.8%.
For Y - "Percentage of mass composition" = ("Mass contributuon")/("Total mass")*100 = (3(16))/(2(75)+3(16))*100 = 24.2424... =24.2%#.