How many grams of oxygen are needed to react completely with 200.0 g of ammonia, NH₃? 4NH₃(g) + 5O₂(g) → 4NO(g) + 6H₂O(g) A)469.7 g B)300.6 g C)250.0 g D)3.406 g E)2.180 g

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Quizplus · Accepted Answer

The balanced chemical equation is $4NH_3 + 5O_2 \rightarrow 4NO + 6H_2O$. The molar mass of $NH_3$ is approximately 17 g/mol (14 for nitrogen and 1 for each hydrogen), so 200.0 g of $NH_3$ is about $200.0 \, \text{g} \div 17 \, \text{g/mol} = 11.76 \, \text{mol}$. According to the stoichiometry of the reaction, 5 moles of $O_2$ are needed for every 4 moles of $NH_3$, so for 11.76 moles of $NH_3$, $11.76 \, \text{mol} \times \frac{5}{4} = 14.7 \, \text{mol}$ of $O_2$ are needed. The molar mass of $O_2$ is approximately 32 g/mol (16 for each oxygen), so $14.7 \, \text{mol} \times 32 \, \text{g/mol} = 469.6 \, \text{g}$, which rounds to 469.7 g.

How Many Grams of Oxygen Are Needed to React Completely