Final answer:
The limiting reactant is MgF₂.
Step-by-step explanation:
The limiting reactant in a chemical reaction is the reactant that is completely used up and determines the amount of product that can be formed. To determine the limiting reactant, we need to compare the amount of each reactant to their respective coefficients in the balanced chemical equation.
In this case, we have 22.25 g of Na and 39.5 g of MgF₂. To find the limiting reactant, we need to convert the grams of each reactant to moles using their molar masses.
For Na: 22.25 g Na x (1 mol Na / 22.99 g Na) = 0.967 mol Na
For MgF₂: 39.5 g MgF₂ x (1 mol MgF₂ / 62.3 g MgF₂) = 0.633 mol MgF₂
Now, we need to compare the mole ratio between Na and MgF₂ in the balanced equation. The balanced equation is: 2Na + MgF₂ → 2NaF + Mg
The mole ratio between Na and MgF₂ is 2:1. This means that for every 2 moles of Na, 1 mole of MgF₂ is required for complete reaction.
Since we have more moles of Na (0.967 mol) compared to MgF₂ (0.633 mol), Na is in excess and MgF₂ is the limiting reactant.