The Law of Conservation of Mass says that matter cannot be created or destroyed. This means that in a closed system, everything that is there at the start must still be there at the end, just in different forms. This idea is very important in chemistry, especially in a branch called stoichiometry. Stoichiometry helps us figure out how much of each substance is involved in chemical reactions.

Here are some key points:

• In any chemical reaction, the total mass of the starting materials (reactants) must equal the total mass of the end materials (products).

• This means if you begin with a certain amount of reactants, when the reaction is done, the products will weigh the same.

In stoichiometry, this law is super important. It helps chemists predict how much of each substance will be used or produced. When we balance a chemical equation, it shows that mass is conserved. For example, if a reaction uses 10 grams of materials, you will end up with 10 grams of products once the reaction is finished.

Now, let’s talk about how we can show this mathematically:

• Balanced equations display the relationship between reactants and products as ratios.

• If we look at a reaction like this: $aA + bB \rightarrow cC + dD$ where $a$, $b$, $c$, and $d$ are numbers that tell us how many molecules are involved, we can use these ratios to find out the mass of each substance.

Knowing the Law of Conservation of Mass is really helpful. It makes sure our stoichiometry calculations are correct. Plus, it lays the groundwork for more advanced topics in chemistry, like figuring out limiting reactants and how much product we can make. In short, it connects the idea of mass in chemical reactions with practical calculations we use in chemistry.