How many grams of product are formed from 2.0 mol of N2 (g) and 8.0 mol of Mg(s)? Show all calculations leading to an answer.

Answer 1

This is a limiting reagent problem. You know that when amounts are given for BOTH reactants.
3Mg + N2 ==> Mg3N2

a. Convert mols Mg to mols product.
b. Convert mols N2 to mols product.
These answers are likely to be different; if so then both can't be right. The correct value in limiting reagent problems is ALWAYS the smaller number and the reagent responsible for that is the limiting reagent.
Use the smaller number of mols for the product and convert that to grams product. That will be done with g = mols Mg3N2 x molar mass Mg3N2.
Post your work if you get stuck.