Here's why:
* Limiting reactant: This reactant determines the maximum amount of product that can be formed. Once it's all gone, the reaction stops, even if there's still some of the other reactant left.
* Excess reactant: The other reactant that is not fully consumed is called the excess reactant.
Think of it like baking a cake:
* You need 2 cups of flour and 1 cup of sugar.
* If you only have 1 cup of flour, you can only make half a cake, even if you have plenty of sugar.
* Flour is the limiting reactant, and sugar is the excess reactant.
