Question

When 0.55 grams of Magnesium is heated in a nitrogen atmosphere, a chemical reaction occurs. The product of the reaction weights 0.76 grams. Calculate the empirical formula of the compound containing Mg and N.

Answer 1

Answer:

Mg₃N₂

Explanation:

The reaction of Mg + N₂ produces:

Mg + N₂ → MgₓNₙ

0.55g of Mg are:

0.55g ₓ (1 mol / 24.305g) = 0.0226 moles of Mg

Now, as the product has 0.76g of mass, mass of nitrogen is:

0.76g - 0.55g = 0.21g of N. In moles:

0.21g ₓ (1 mol / 14g) = 0.015 moles of N

The ratio in moles of N:Mg is:

0.0226 / 0.015 = 1.5. That means you have 1.5 atoms of Mg per atom of N. As empirical formula is the simplest whole-number ratio of atoms in a compound, empirical formula in the problem is:

Mg₃N₂