What is the Difference Between Law of Conservation of Mass and Law of Constant Proportion?

The Law of Conservation of Mass and the Law of Constant Proportion (also known as the Law of Definite Proportions) are two important scientific laws in chemistry. The key difference between the two lies in their focus on mass and composition, respectively.

Law of Conservation of Mass:

• States that matter cannot be created or destroyed, but it can be transformed from one form to another.
• In a closed system, the total mass remains constant over time, meaning it cannot be added or removed.
• This law supports the idea that the quantity of matter remains constant during physical and chemical changes.

Law of Constant Proportion:

• States that a given chemical compound always contains the same elements in the exact same proportions by mass.
• Asserts that a given chemical compound can always be composed of its component elements in a fixed ratio by mass.
• This law supports the idea that the composition of a chemical compound remains constant, irrespective of its source or method of preparation.

In summary, the Law of Conservation of Mass focuses on the conservation of mass during physical and chemical changes, while the Law of Constant Proportion focuses on the consistent composition of chemical compounds.

Comparative Table: Law of Conservation of Mass vs Law of Constant Proportion

Here is a table comparing the Law of Conservation of Mass and the Law of Constant Proportion:

In summary, the Law of Conservation of Mass concerns the conservation of mass in any physical or chemical process, while the Law of Constant Proportion focuses specifically on the fixed ratios of elements in chemical compounds.