Law of Conservation of Mass and Landolt Experiment

Law of Conservation of Mass:Antoine Lavoisier, a French chemist, stated the law of conservation of mass in 1785.

Statement:

"In any chemical reaction, the initial weights of reactants is equal to the final weights of products"OR
"Mass is neither created nor destroyed during a chemical reaction but it only changes from one form to another"

Example:

1. Water forms by the union of hydrogen and oxygen. If we weigh the reactants (hydrogen and oxygen) before the chemical reaction, we find the weight of the product (water) equal to the combined weight of reactants.
2. The weight of iron increases on rusting. The increase in weight is equal to the weight of oxygen added to iron.

Landolt Experiment:
H. Landolt was German Chemist. He proved the law of conservation of mass by using an H-shaped glass tube. he filled silver nitrate in limb A and hydrochloric acid in limb B. The tube was sealed and weighed before the chemical reaction. The reactants were mixed by inverting and shaking the tube. A white precipitate of silver chloride was formed along with nitric acid. The tube was weighed again. He found that there was no change in weight during the following chemical reaction.

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