What is the formula of #"magnesium nitride"#, #Mg_3N_2#?

1 Answer
Apr 22, 2016

Answer:

Consider the typical valencies of magnesium metal and dinitrogen in their compounds.

Explanation:

Magnesium is a Group 2 metal with 2 valence electrons that can be oxidized:

#Mg rarr Mg^(2+) + 2e^-#

Dinitrogen is a gaseous non-metal that can be reduced to #N^(3-)#: Each nitrogen ATOM has 5 valence electrons, and this configuration can be reduced to #N^(3-)#.

#1/2N_2(g) + 3e^(-)rarrN^(3-)#

Since typically non-metals can oxidize metals, or metals reduce non-metals, we cross multiply to give the stoichiometric equation:

#3Mg(s) + N_2(g) rarr Mg_3N_2(s)#

Such a reaction is called a nitriding reaction. It would require conditions of high temperature.