In the following reaction, 12.0 moles of Mg(OH)2 and 16.0 moles of HCl react. Who is the limiting reactant?

The limiting reactant is HCl because you would need at least 24.0 moles of HCl for all of the Magnesium Hydroxide to react. This is because there need to be twice as many moles of HCl than there are of Magnesium Hydroxide

39.98 liters

Explanation:

The first you should know:  At STP , 1 mole of any  gas takes up 22.4 Liters of volume.

After, you will find the molecular weight (MW) of N2 with help of a periodic table.

Then N= 14,007 g      

So:  

N2 = 14,007 * 2      

MW =28,014 g/ mol N2  

Now you will start with the data of 50 grams of N2 and you obtain:    

50 g N2  x 1 mol N2    x  22.4 L N2      =  39.98 L at STP                                 28,014 g N2        1 mol N2