Stoichiometry is the branch of chemistry that deals with the quantitative relationships between the reactants and products in a chemical reaction. In simple terms, it is the study of how much of each substance is needed or produced in a reaction.
It is based on the law of conservation of mass, which states that matter is neither created nor destroyed in a chemical reaction. This means the total number of atoms of each element must be the same on both the reactant side and the product side of a balanced chemical equation.
Stoichiometry helps chemists:
- Determine the exact proportions of reactants required for a reaction.
- Calculate the amount of products that will form.
- Identify the limiting reactant (the one that gets used up first).
- Predict yields in laboratory experiments and industrial processes.
For example, if hydrogen reacts with oxygen to form water, stoichiometry can be used to calculate how many grams of hydrogen are needed to react completely with a certain amount of oxygen, or how many grams of water will be produced.