Question

If a 9.983 g sample of calcium sulfate dihyrate was heated in a crucible under the correct conditions, how many grams of water should be lost?

Answer 1

2.090 g

Step-by-step explanation:

The chemical formula of calcium sulfate dihydrate is CaSO₄.2H₂O.

• The mass of 1 mole of CaSO₄ is 136.14 g.

• The mass of 2 moles of H₂O is 2 × 18.02 g = 36.04 g.

• The mass of 1 mole of CaSO₄.2H₂O is 136.14 g + 36.04 g = 172.18 g.

The mass ratio of CaSO₄.2H₂O to H₂O is 172.18 g:36.04 g. The mass of water lost upon the heating of 9.983 g of CaSO₄.2H₂O is:

9.983 g CaSO₄.2H₂O × (36.04 g H₂O/172.18 g CaSO₄.2H₂O) = 2.090 g H₂O