Final answer:
To find the empirical formula of a compound with elements X and Y based on the given percentages, the mass of each element in a 100 g sample was calculated, then converted to moles, and finally the mole ratio was simplified to determine that the empirical formula is X₂Y₃.
Step-by-step explanation:
The student asked which compound is formed when two elements X (atomic mass = 75) and Y (atomic mass = 16) combine to give a compound with 75.8% of X by mass. To determine the empirical formula of the compound, we first need to calculate the mole ratio of the elements X and Y.
Step 1: Calculate the mass of X and Y in 100 g of the compound.
- Mass of X = 75.8 g
- Mass of Y = 100 g - 75.8 g = 24.2 g
Step 2: Calculate moles of X and Y using their atomic masses.
- Moles of X = 75.8 g / 75 g/mol = 1.0107 moles
- Moles of Y = 24.2 g / 16 g/mol = 1.5125 moles
Step 3: Determine the simplest whole number ratio.
- The ratio of X to Y is approximately 1:1.5, which simplifies to 2:3.
Thus, the empirical formula of the compound is X₂Y₃. There is a typo in the given options, but based on the choices, answer B would be closest if it were corrected to X₂Y₃.