Chapter 1 · Stoichiometry — Interactive Lecture

Why do we need stoichiometry?

A balanced equation tells us the mole ratio in which substances react. For water, 2 molecules of H₂ react with 1 molecule of O₂ to make 2 molecules of H₂O.

Set the amounts on the right and press React. Watch which reactant runs out first — that one is the limiting reactant, and it decides how much product you can make.

• Mole ratio H₂ : O₂ : H₂O = 2 : 1 : 2
• The limiting reactant is fully used up.
• The excess reactant is left over.
• Product formed depends only on the limiting reactant.