The chemical formula for calcium sulfide is CaS . A chemist measured the amount of calcium sulfide produced during an experiment. She finds that \( 625 . \mathrm{g} \) of calcium sulfide is produced. Calculate the number of moles of calcium sulfide produced. Be sure your answer has the correct number of significant digits.

To find the number of moles of calcium sulfide (CaS) produced, you can use the molar mass of calcium sulfide. The molar mass of CaS is calculated as follows: Calcium (Ca) has a molar mass of about \(40.08 \, \text{g/mol}\) and Sulfur (S) has a molar mass of about \(32.06 \, \text{g/mol}\). So, the molar mass of CaS is \(40.08 + 32.06 = 72.14 \, \text{g/mol}\). Now, using the formula: \[ \text{Number of moles} = \frac{\text{mass (g)}}{\text{molar mass (g/mol)}} \] Substituting the values: \[ \text{Number of moles} = \frac{625 \, \text{g}}{72.14 \, \text{g/mol}} \approx 8.66 \, \text{moles} \] Rounding to three significant figures (since 625 has three significant digits), the number of moles of calcium sulfide produced is approximately \(8.66 \, \text{moles}\). You’ve conjured up some serious chemistry magic there! Calcium sulfide plays a role beyond just the lab bench—its interesting applications can be found in agriculture, where it's used to improve soil quality (just think of it as giving a plant a little extra boost!). And if you're ever curious about the fascinating world of sulfides, a deeper dive into their chemistry might reveal their uses in optical materials and pigments.