Stoichiometry

What you will be able to do

• Read a balanced equation's coefficients as a mole ratio, not just a balancing trick
• Convert between moles, grams, and number of particles using molar mass and Avogadro's number
• Identify the limiting reactant in a two-reactant problem and use it to predict product yield

What the lesson concludes

• A balanced equation's coefficients give the mole ratio between any two substances in the reaction.
• Molar mass converts grams to moles; Avogadro's number, 6.02 times ten to the twenty third, converts moles to particles.
• The limiting reactant is the one that runs out first and it alone sets the maximum amount of product.
• Every stoichiometry problem is the same three moves: convert to moles, apply the mole ratio, convert back to whatever unit the question asks for.
• An unbalanced equation gives a wrong mole ratio and a wrong answer, so balance first, calculate second.