Final answer:
The empirical formula for a compound that contains 15.0% C, 5.0% H, and 80.0% S by mass is calculated by converting the percentages into moles, finding the smallest mole ratio and simplifying it to the smallest whole numbers. The calculation results in a mole ratio of C:H:S of approximately 1:4:2, which corresponds to the empirical formula CH4S2, not given in the options.
Step-by-step explanation:
Finding the Empirical Formula
To determine the empirical formula of a compound with 15.0% C, 5.0% H, and 80.0% S by mass, you need to convert these percentages into moles by using the atomic masses of each element:
- C: 12.01 g/mol
- H: 1.008 g/mol
- S: 32.06 g/mol
Next, divide each element's percentage by its atomic mass to find the mole ratio:
- For C: 15.0 g / 12.01 g/mol = 1.25 moles
- For H: 5.0 g / 1.008 g/mol = 4.96 moles
- For S: 80.0 g / 32.06 g/mol = 2.495 moles
Lastly, divide each mole value by the smallest number of moles calculated:
- For C: 1.25 moles / 1.25 moles = 1
- For H: 4.96 moles / 1.25 moles = ~4
- For S: 2.495 moles / 1.25 moles = 2
The mole ratio of C:H:S is approximately 1:4:2. Therefore, the empirical formula is CH4S2, which is not listed as one of the provided answer choices. It seems like there may be an error either in the question or the provided answer choices.