Explain the Law of Definite Proportions with examples.

(N/A) The Law of Definite Proportions was proposed by the French chemist $Joseph \ Proust$. He stated that a given chemical compound always contains exactly the same proportion of elements by weight,regardless of its source or method of preparation.
$Proust$ worked with two samples of cupric carbonate $(CuCO_3)$—one of natural origin and the other synthetic. He found that the composition of elements present in both samples was identical,as shown in the table below:

Sample Type	$\% \text{ of Copper}$	$\% \text{ of Carbon}$	$\% \text{ of Oxygen}$
Natural sample	$51.35$	$9.74$	$38.91$
Synthetic sample	$51.35$	$9.74$	$38.91$

Thus,irrespective of the source,a given compound always contains the same elements in the same proportion by mass. This law is also known as the Law of Definite Composition.