Based upon the previous two questions, consider the magnesium nitride addition reaction again. This time, suppose you start with 10.0 g of each reactant. What is the maximum number of MOLES of Mg3N2 that could be produced in this case? Remember that the reactant that runs out first is called the LIMITING REACTANT.
To find the maximum number of moles of Mg3N2 that can be produced, we need to determine the limiting reactant.
Step 1: Write the balanced chemical equation for the reaction:
3 Mg + N2 -> Mg3N2
Step 2: Calculate the number of moles for each reactant:
Moles of Mg = mass of Mg (g) / molar mass of Mg (g/mol)
Moles of N2 = mass of N2 (g) / molar mass of N2 (g/mol)
Given:
Mass of Mg = 10.0 g
Molar mass of Mg = 24.31 g/mol (from the periodic table)
Mass of N2 = 10.0 g
Molar mass of N2 = 28.01 g/mol (from the periodic table)
Calculating:
Moles of Mg = 10.0 g / 24.31 g/mol = 0.41 mol
Moles of N2 = 10.0 g / 28.01 g/mol = 0.36 mol
Step 3: Compare the mole ratio between Mg3N2 and each reactant in the balanced chemical equation. The reactant with the smaller mole ratio is the limiting reactant.
From the balanced equation, we can see that the mole ratio between Mg3N2 and Mg is 1:3, which means that 3 moles of Mg is required to produce 1 mole of Mg3N2.
Mole ratio between Mg3N2 and Mg = 1:3
Mole ratio between Mg3N2 and N2 = 1:1
The mole ratio between Mg3N2 and N2 is 1:1, indicating that 1 mole of N2 is required to produce 1 mole of Mg3N2.
Step 4: Compare the actual number of moles of each reactant to their respective mole ratios.
Actual moles of Mg (0.41 mol) / Mole ratio between Mg3N2 and Mg (3) = 0.41 mol / 3 = 0.14 mol
Actual moles of N2 (0.36 mol) / Mole ratio between Mg3N2 and N2 (1) = 0.36 mol / 1 = 0.36 mol
From the calculations, we can see that the actual number of moles of N2 (0.36 mol) is smaller than the actual number of moles of Mg (0.41 mol). This means that N2 is the limiting reactant.
Step 5: Calculate the maximum number of moles of Mg3N2 that can be produced using the limiting reactant (N2).
Since N2 is the limiting reactant, its number of moles determines the maximum number of moles of Mg3N2 that can be produced. In this case, 0.36 moles of Mg3N2 can be produced.
Therefore, the maximum number of moles of Mg3N2 that can be produced is 0.36 moles.