Question

1 g of magnesium is mixed with 0.56 g of O2 in a closed vessel. Which reactant is left in excess and how much?

a. Magnesium; 0.26 g
b. Magnesium; 0.44 g
c. Oxygen; 0.26 g
d. Oxygen; 0.44 g

Answer 1

The limiting reactant is magnesium and the excess reactant is oxygen.

Step-by-step explanation:

Step 4: The reactant that produces a smaller amount of product is the limiting reactant. Mg produces less MgO than does O₂ (3.98 g MgO vs. 25.2 g MgO), therefore Mg is the limiting reactant in this reaction. Step 5: The reactant that produces a larger amount of product is the excess reactant.