In the reaction N_2 + 3H_2 → 2NH_3, how many moles of hydrogen gas (H_2) are required to completely react with 0.85 moles of nitrogen gas (N_2)?

• A. 0.85 moles
• B. 0.43 moles
• C. 2.55 moles
• D. 1.70 moles

Answer: (C)

Verified step by step guidance

1. Identify the balanced chemical equation: \(\mathrm{N_2 + 3H_2 \rightarrow 2NH_3}\).
2. Note the mole ratio between nitrogen gas (\(\mathrm{N_2}\)) and hydrogen gas (\(\mathrm{H_2}\)) from the balanced equation, which is 1 mole of \(\mathrm{N_2}\) reacts with 3 moles of \(\mathrm{H_2}\).
3. Given the amount of nitrogen gas is 0.85 moles, use the mole ratio to find the moles of hydrogen gas required by multiplying: \$0.85 \text{ moles } \mathrm{N_2} \times \frac{3 \text{ moles } \mathrm{H_2}}{1 \text{ mole } \mathrm{N_2}}$.
4. Set up the calculation without solving it to find the moles of \(\mathrm{H_2}\) needed to completely react with 0.85 moles of \(\mathrm{N_2}\).
5. Interpret the result as the amount of hydrogen gas required for complete reaction according to the stoichiometry of the balanced equation.