Answer:
The limiting reagent is O2
Step-by-step explanation:
From the equation of reaction,
2 moles of H2S is required to react with 3 moles of O2
Therefore, 20 grams of H2S is required to react with (20×3/2 = 30 grams) of O2
30 grams of O2 is required to react with 20 grams of H2S but only 20 grams of O2 is available
Therefore, the limiting reagent (reagent in small supply) is O2
