Describe the experiment conducted by Joseph L. Proust, which lead him

Describe the experiment conducted by Joseph L. Proust, which lead him to propose law of constant proportions.

Answer»

Proust took two samples of copper carbonate, one from nature and another prepared in the lab.
These two samples are chemically decomposed to find percentage of copper, carbon and oxygen.
The results obtained are given in the table.

From the above table we observe that the percentage of copper, carbon and oxygen atoms in two samples are same.
Based on this observation Proust proposed the law of constant proportions as “A given chemical substance always contains the same elements combined in a fixed proportions by weight”.