✔ 最佳答案
You need "2 H2S(g)" on the left. The only given equation that mentions H2S(g) is the first one, so write the first given equation backwards:
2 H2S(g) + SO2(g) → 3 S(s) + 2 H2O(g), ΔH = −146.9 kJ
You also need "3 O2(g)" on the left. The only given equation that mentions O2(g) is the second one, so multiply the second given equation by 3:
3 S(s) + 3 O2(g) → 3 SO2(g), ΔH = −889.2 kJ
Add the two equations here:
2 H2S(g) + SO2(g) + 3 S(s) + 3 O2(g) →3 S(s) + 2 H2O(g) + 3 SO2(g),
ΔH = −146.9 kJ −889.2 kJ
Cancel like amounts on opposite sides of the arrow, and do the arithmetic for ΔH:
2 H2S(g) + 3 O2(g) → 2 H2O(g) + 2 SO2(g), ΔH = −1036.1 kJ