Answer:
45.8 g
Step-by-step explanation:
M_r: 34.08
2H₂S + SO₂ ⇌ 3S + 2H₂O ; ΔH°r = -670 kJ
1. Calculate the moles of H₂S
Treat the heat as if it were a product in the equation. Then use the molar ratio (2 mol H₂S/670 kJ) in the usual way.
Moles of H₂S = 450 kJ × 2 mol H₂S/670 kJ = 1.343 mol H₂S
2. Calculate the mass of H₂S
Mass of H₂S = 1.343 mol H₂S × (34.08 g H₂S/1 mol H₂S) = 45.8 g H₂S
You need 45.8 g of H₂S to produce 450 kJ of energy.
