Why is the term limiting used to describe the limiting reactant?

Stoichiometry is the mathematical relationship between reactants and products in a chemical reaction. It's like a recipe for chemistry, providing the exact proportions needed to create a particular product. Just like you need the right ratio of flour to sugar to bake cookies successfully, in chemistry, stoichiometry ensures that reactants combine in the correct proportions according to the balanced chemical equation.

To better understand stoichiometry, imagine making sandwiches. If you have 10 slices of bread and 5 slices of cheese, you can only make 5 sandwiches. The bread and cheese represent reactants, and the sandwiches are the product. The stoichiometry of this 'reaction' would be 2 slices of bread to 1 slice of cheese permitting the assembly of one sandwich.

In a chemical reaction, substances called reactants interact to form products. For the reaction to take place, these reactants must collide with sufficient energy and in the correct arrangement. The type of chemical reaction—whether it's a synthesis, decomposition, or another kind—determines how reactants transform into products.

Consider the simple act of lighting a candle. The wax and oxygen in the air act as reactants. When you light the wick, the heat of the flame helps the wax and oxygen react chemically to produce water vapor, carbon dioxide, heat, and light, which are the products. The entire process is driven by the interaction and transformation of the reactants.

Reactant ratios are crucial for determining the amount of each substance involved in a chemical reaction. These ratios, derived from the balanced chemical equation, dictate the proportions of reactants required for the reaction to run to completion. Failing to balance reactant ratios is like trying to make a cake with double the flour and half the sugar; your final product will not turn out as intended.

In chemical terms, when two substances react in a 1:1 ratio, one molecule of the first reactant will react with one molecule of the second. If you have more of one reactant than the other, the 'extra' will remain unreacted once the reaction ceases, illustrating the concept of the limiting reactant. For instance, if a reaction requires 1 mole of reactant A for every 3 moles of reactant B, and there are 3 moles of A but 10 moles of B, A becomes the limiting reactant, dictating how much product is ultimately formed.