Question

What is the formula of the compound between calcium and sulfur that has the percent composition 55.6% (by mass) calcium and 44.4% (by mass) sulfur? What is the formula of the compound between calcium and sulfur that has the percent composition 55.6% (by mass) calcium and 44.4% (by mass) sulfur? Ca2S4 CaS Ca2S CaS4 CaS2 Request

Answer 1

Answer: The empirical formula is
`CaS`

Step-by-step explanation:

If percentage are given then we are taking total mass is 100 grams.

So, the mass of each element is equal to the percentage given.

Mass of Ca= 55.6 g

Mass of S = 44.4 g

Step 1 : convert given masses into moles.

Moles of Ca =
`\frac{\text{ given mass of Ca}}{\text{ molar mass of Ca}}= (55.6g)/(40.08g/mole)=1.38moles`

Moles of S =
`\frac{\text{ given mass of S}}{\text{ molar mass of S}}= (44.4g)/(32.06g/mole)=1.38moles`

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For Ca =
`(1.38)/(1.38)=1`

For S =
`(1.38)/(1.38)=1`

The ratio of Ca : S = 1:1

Hence the empirical formula is
`CaS`