Question

What is the empirical formula of the compound containing $36.5\% $ sulfur and $63.5\% $ Iron?
A. $FeS$
B. $F{e_{63}}{S_{36}}$
C. $F{e_2}S$
D.$F{e_2}{S_2}$
E. $2FeS$

Answer 1

Hint: The empirical formula, often known as the simplest formula, yields the lowest whole number ratio of atoms in a molecule. This formula specifies the relative number of atoms in each element in the compound. Unlike molecular formulas, empirical formulas do not provide information about the absolute number of atoms in a single molecule of a compound.

Complete answer:
$100g$ of compound will contain $36.5g$ of sulfur ($S$ ) and $63.5g$ of iron ($Fe$ )
The atomic mass of sulfur is $32.1gmo{l^{ - 1}}$
The atomic mass of iron is $55.8gmo{l^{ - 1}}$
Number of moles can be calculated by using the following formula:
$\text{Number of moles } = \dfrac{\text{Mass}}{\text{Molar mass}}$
Number of moles of $S$ $ = \dfrac{{36.5}}{{32.1}}$
Number of moles of $S$$ = 1.137$
Number of moles of $Fe$$ = \dfrac{{63.5}}{{55.8}}$
Number of moles of $Fe = 1.137$
From the above calculations, we can conclude that the ratio of the number of moles of $Fe$ to the number of moles of $S$ is $1.137:1.137$ that is $1:1$ .
Therefore, the empirical formula $FeS$ .
Hence, the correct answer is “Option A”.

Note:
The most basic kind of notation is empirical formulas. A compound's molecular formula is the same as or a whole-number multiple of its empirical formula. Empirical formulas, like molecular formulas, are not unique and can describe a variety of chemical structures or isomers.