5g of calcium reacts completely with 10g of sulfur. what is the percent composition of the calcium sulfide (CaS) produced? show complete solution
Answer:
the percent composition of calcium sulfide (CaS) is 28.57% calcium and 71.43% sulfur.
Explanation:
Molar mass of calcium (Ca) = 40.08 g/mol
Molar mass of sulfur (S) = 32.06 g/mol
Moles of calcium (Ca) = mass of calcium / molar mass of calcium
= 5g / 40.08 g/mol
= 0.1247 mol
Moles of sulfur (S) = mass of sulfur / molar mass of sulfur
= 10g / 32.06 g/mol
= 0.3117 mol
The ratio of calcium to sulfur in calcium sulfide (CaS) is 1:1. Therefore, the moles of calcium and sulfur are equal.
Percent composition of calcium (Ca) = (moles of calcium / total moles) * 100
= (0.1247 mol / (0.1247 mol + 0.3117 mol)) * 100
= 28.57%
Percent composition of sulfur (S) = (moles of sulfur / total moles) * 100
= (0.3117 mol / (0.1247 mol + 0.3117 mol)) * 100
= 71.43%
Therefore, the percent composition of calcium sulfide (CaS) is 28.57% calcium and 71.43% sulfur.