Stoichiometry

What we are going to learn today? What is Stoichiometry? How will I use it?

What in the heck is this “Stoichiometry” stuff? Stoichiometry is a way to convert units! Stoichiometry is a set of calculations you perform to figure out how much stuff you can make in a reaction, or how much stuff you will need to make the reaction occur. It tells you if you have enough material (reactant) to make what you want to make (product) Example – sandwiches (yum!)

Chemical equations relate: Number of molecules required to react in the equation Number of moles of reactants and products required for the reaction In a balanced equation all parts are equal so we can use in conversion factors to change from one substance to another

Using the equation below: N2 + 3H2 → 2NH3 1molN2 = 3 molH2 = 2 molNH3 Use the mole ratio to convert from one substance to another

N2 + 3H2 → 2NH3 What is the mole ratio for N2 and H2? What is the mole ratio for H2 and NH3? What is the mole ratio for N2 and NH3?

N2 + 3H2 → 2NH3 How many mol NH3 can be made from 3.2mol H2 if excess N2 is present? How many mol N2 are needed to make 0.019mol NH3 if excess H2 is present?

6Na + Fe2O3 → 3Na2O + 2Fe How many mol Fe2O3 are required to completely react 4.04 mol Na? How many mol Na2O can be made from 2.073 mol Na if excess Fe2O3 is present?