Mole Ratio Method


Hi, I'm Rachel, and today we're going to be going over mole ratio method. So let's say we have the equation nitrogen and 2, plus hydrogen H2 makes ammonium at H3. So what we're doing with mole ration method is we are finding the amount of moles and how they relate to each other. So we're using the reactants and the products, and we want to find what's the ratio in moles from reactants to products, and reactants to other reactants, and products to other products. So let's look at what this means. Well first we want to balance the chemical equation, that's very important. So let's balance it. We have nitrogen here, we have 2 nitrogen on the reactant side. On the product side we only have 1 nitrogen, so we're gonna need to add a coefficient, a 2, so that we get 2 nitrogen on this side and 2 nitrogen on that side, Now let's look at the hydrogen. We have 6 hydrogen because we multiply 2 x 3 to get 6 hydrogen. So we're gonna have to add 3 more hydrogen here so that it is 6 hydrogen on this side and 6 hydrogen on this side. And now the equation is balanced, so we can find the mole ratios. You can write that as, 1 mole of N2, right, we have 1 mole of N2 to example 2 moles of ammonium. That's one way to write the mole ratio, you can also write just 1:2, like that. Another example is, we have 3 moles of the hydrogen to 2 moles of the ammonium. So that's just the example, you're just comparing the different ratios of the reactants and the products, like so after you balanced out the chemical equation. I'm Rachel, and thanks for learning about mole ratio method with me.

Rachel Kaplove has worked as a professional private tutor since 2005. Specializing in Math and Science, she tutors students from the second grade level to advanced high school honors levels.