If 12 mol of lithium were reacted with excess nitrogen gas, how many moles of lithium nitride would be produced

The balanced reaction that describes the reaction between lithium and nitrogen gas to produce lithium nitride is expressed 6Li + N2 = 2Li3N. Hence for every 6 moles of lithium used, there are 2 moles of lithium nitride produced. For this problem, 12 moles of lithium yields 4 moles of lithium nitride.