Answer:
285 g
Step-by-step explanation:
Let's consider the following balanced equation.
Cr₂O₃(s) + 3 H₂S(g) ⟶ Cr₂S₃(s) + 3 H₂O(l)
The molar mass of H₂S is 34.1 g/mol and there are 3 mol × 34.1 g/mol = 102 g in the balanced equation.
The molar mass of Cr₂S₃ is 200.19 g/mol and there are 1 mol × 200.19 g/mol = 200.19 g in the balanced equation.
The mass ratio of H₂S to Cr₂S₃ is 102 g: 200.19 g. The mass of H₂S required to produce 560 g of Cr₂S₃ is:
560 g Cr₂S₃ × (102 g H₂S/200.19 g Cr₂S₃) = 285 g H₂S