Lithium and nitrogen react to produce lithium nitride according to the equation: 6Li + N2 → 2Li3N. How many moles of N2 are needed to react with 0.450 mol of lithium?

• A. 0.075 mol
• B. 0.225 mol
• C. 0.300 mol
• D. 0.150 mol

Answer: (A)

Verified step by step guidance

1. Identify the balanced chemical equation: 6Li + N2 → 2Li3N. This equation shows the stoichiometric relationship between lithium (Li) and nitrogen (N2).
2. Determine the mole ratio between lithium (Li) and nitrogen (N2) from the balanced equation. The coefficients indicate that 6 moles of Li react with 1 mole of N2.
3. Set up a proportion using the mole ratio to find the moles of N2 needed. If 6 moles of Li require 1 mole of N2, then 0.450 moles of Li will require x moles of N2.
4. Use the proportion: \( \frac{6 \text{ moles Li}}{1 \text{ mole N2}} = \frac{0.450 \text{ moles Li}}{x \text{ moles N2}} \). Solve for x to find the moles of N2.
5. Calculate the value of x by cross-multiplying and dividing: \( x = \frac{0.450 \times 1}{6} \). This will give you the moles of N2 needed to react with 0.450 moles of lithium.