Balanced chemical reaction happening here is:
3Mg(s) + N₂(g) → Mg₃N₂(s)
moles of product formed from each reactant:
2.0 mol of N2 (g) x 1 mol Mg₃N₂ = 2 mol Mg₃N₂
1 mol N2
and
8.0 mol of Mg(s) x 1 mol Mg₃N₂ = 2.67 mol Mg₃N₂
3 mol Mg
Since N2 is giving the least amount of product(Mg₃N₂) ie. 2 mol Mg₃N₂
N2 is the limiting reactant here and Mg is excess reactant.
Hence mole of product formed here is 2 mol Mg₃N₂
molar mass of Mg₃N₂
= 3 Mg + 2 N
= 101g/mol
mass of product(Mg₃N₂) formed
= moles x Molar mass
= 2 x 101
= 202g Mg₃N₂
202g of product are formed from 2.0 mol of N2(g) and 8.0 mol of Mg(s).
The following are indicators of chemical changes:
Change in Temperature
Change in Color
Formation of a Precipitate