Q: What is the Law of Conservation of Mass?
A: The Law of Conservation of Mass is a fundamental principle in chemistry and physics. It states that mass can neither be created nor destroyed in a chemical reaction. This means the total mass of the reactants (substances you start with) is always equal to the total mass of the products (substances formed). In simple words, matter does not disappear or appear out of nowhere—it only changes form.
Example:
When a piece of wood burns, it seems to vanish into ashes. But if you collect the ash, smoke, gases, and heat energy released, their combined mass equals the original mass of the wood plus the oxygen it reacted with. Similarly, when you dissolve salt in water, the total mass of the solution is equal to the mass of salt and water combined.
FAQs
1. Who discovered the Law of Conservation of Mass?
The law was discovered by Antoine Lavoisier in the late 18th century. He is often referred to as the “Father of Modern Chemistry.”
2. Why is the Law of Conservation of Mass important?
It is important because it helps scientists balance chemical equations and understand that matter is never lost—only transformed.
3. Does the Law of Conservation of Mass apply in everyday life?
Yes. For example, cooking, burning, or dissolving substances all follow this law, as the total mass before and after remains the same.
4. Does the Law of Conservation of Mass apply in nuclear reactions?
In nuclear reactions, a tiny amount of mass converts into energy (according to Einstein’s equation E=mc²), so the law is slightly modified at that level.
5. How is the Law of Conservation of Mass used in chemistry?
It is mainly used to balance chemical equations, ensuring that the number of atoms of each element remains the same on both sides of the reaction.