# If 558 kg of powdered iron react with powdered sulfur to produce 879 kg of iron sulfide, what is the mass of reacting sulfur?

Jan 29, 2017

Well, is not mass conserved in a chemical reaction?

#### Explanation:

Of course, mass is conserved in every chemical reaction. If there are $879 \cdot k g$ of $\text{iron sulfide}$, and $558 \cdot k g$ of $\text{iron}$, then $321 \cdot k g$ sulfur must have reacted.

Further, we can calculate the empirical formula of the $\text{iron sulfide.....}$

$\text{Moles of iron}$ $=$ $\frac{558 \cdot k g}{0.0558 \cdot k g \cdot m o {l}^{-} 1} = 10000 \cdot m o l .$

$\text{Moles of sulfur}$ $=$ $\frac{321 \cdot k g}{0.03206 \cdot k g \cdot m o {l}^{-} 1} = 10000 \cdot m o l .$

Given $1 : 1$ molar equivalence, we have $F e S$.