Question

Suppose that we combined 75 g of magnesium with 45 g of nitrogen and heat them up. Predict the product of

the reaction, determine the limiting reactant, and calculate the theoretical yield.

Answer 1

Mg is the limiting reactant

The theoretical yield is 105.2 g of Mg3N2

Step-by-step explanation:

3Mg(s) + N2(g) -----> Mg3N2(s)

Number of moles of Mg = 75g/24g/mol = 3.125 moles

3 moles of Mg yields 1 mole of Mg3N2

3.125 moles of Mg yields 3.125 × 1/3 = 1.042 moles of Mg3N2

Number of moles of N2 = 45g/28g/mol = 1.607 moles

1 mole of N2 yields 1 mole of Mg3N2

1.607 moles of N2 yields 1.607 moles Mg3N2

Hence, Mg is the limiting reactant

The theoretical yield of Mg3N2 = 1.042 moles of Mg3N2 × 101 g/mol = 105.2 g of Mg3N2