Answer :

To determine the products formed during the decomposition of magnesium nitride ([tex]$Mg_3N_2$[/tex]), we need to analyze the chemical reaction. Magnesium nitride decomposes when heated, producing magnesium and nitrogen gas.

The balanced decomposition reaction is:
[tex]\[ Mg_3N_2 \rightarrow 3Mg + N_2 \][/tex]

Here, one mole of magnesium nitride decomposes to produce three moles of magnesium and one mole of nitrogen gas.

Let’s verify each given option:

A. [tex]$Mg + 3N_2$[/tex]: This suggests that one mole of magnesium nitride would produce one mole of magnesium and three moles of nitrogen gas. This isn't correct as the actual decomposition gives three moles of magnesium.

B. [tex]$3Mg + 2N_2$[/tex]: This suggests that one mole of magnesium nitride would produce three moles of magnesium and two moles of nitrogen gas. This isn't possible as the nitrogen is correctly balanced in the reaction as one mole of nitrogen gas.

C. [tex]$Mg + 3N$[/tex]: This suggests that one mole of magnesium nitride produces one mole of magnesium and three atoms of nitrogen. This isn't consistent with the actual products of the reaction, which should be molecular nitrogen ([tex]$N_2$[/tex]).

D. [tex]$3Mg + N_2$[/tex]: This correctly reflects the balanced decomposition reaction where one mole of magnesium nitride produces three moles of magnesium and one mole of nitrogen gas.

E. [tex]$2Mg + 3N$[/tex]: This suggests that one mole of magnesium nitride produces two moles of magnesium and three atoms of nitrogen, which is not consistent with the actual balanced reaction.

Given all these considerations, the correct answer is:

D. [tex]$3Mg + N_2$[/tex]