Question

which products are formed during the decomposition of magnesium nitride (mg₃n₂)?

a. mg + 3n₂

b. 3mg + 2n₂

c. mg + 3n

d. 3mg + n₂

e. 2mg + 3n

Explanation:

To determine the products of the decomposition of magnesium nitride ($\ce{Mg_3N_2}$), we use the law of conservation of mass (balanced chemical equation). The decomposition of $\ce{Mg_3N_2}$ should produce magnesium (Mg) and nitrogen gas ($\ce{N_2}$). Let's balance the equation:

The unbalanced decomposition reaction is: $\ce{Mg_3N_2 -> Mg + N_2}$

To balance Mg: There are 3 Mg atoms in $\ce{Mg_3N_2}$, so we put a coefficient of 3 in front of Mg: $\ce{Mg_3N_2 -> 3Mg + N_2}$

To balance N: There are 2 N atoms in $\ce{Mg_3N_2}$ and 2 N atoms in $\ce{N_2}$ (since $\ce{N_2}$ has 2 N atoms per molecule), so the N is already balanced.

So the balanced decomposition reaction is $\ce{Mg_3N_2 -> 3Mg + N_2}$, which means the products are $3\ce{Mg}$ and $\ce{N_2}$.

Answer:

D. $3\ce{Mg} + \ce{N_2}$