CHEMISTRY 101 QUESTION…can someone please explain this stoichiometry problem to me?
For this type of problem, the main goal is to find which reactant is the “limiting reactant”, or which one will run out first. You know you need 3 mol of Si and 2 mol of N2 to produce 1 mol of product. So the first thing you do is figure out how many moles of the product you could make with both of your samples. First for N2 0.62 / 2 = 0.31 (moles divided by number of moles needed for 1 mol product) So if you had unlimited Si, you could make 0.31 mol Si3N4 with your given amount of N2. Then for Si 0.75 / 3 = 0.25 Since you can produce a smaller amount of product with the Si, it is the limiting reactant, after you make 0.25 mol of your product, you will have no Si left and have an excess of N2.
