Chemistry · Ch 1 — Some Basic Concepts of Chemistry
Law of conservation of mass
Law of conservation of mass
The law of conservation of mass was established by the French scientist Antoine Lavoisier (1743-1794), often called the father of modern chemistry, through a careful series of combustion experiments — for instance burning phosphorus and mercury, each in the presence of air, and weighing everything both before and after. In both cases the substance being burned gained weight, but Lavoisier found, after repeated careful experiments, that the weight gained by the burning substance was always exactly equal to the weight lost by the surrounding air — nothing was truly created, it was simply oxygen from the air combining with the burning substance. From this he concluded that the total mass of all the reactants going into a reaction always equals the total mass of all the products coming out of it. For instance, when hydrogen gas burns and combines with oxygen to form water, the mass of the water produced is exactly equal to the combined mas …
Worked out. Own-words account: Antoine Lavoisier (1743-1794), often called the father of modern chemistry, carried out a series of careful combustion experiments — burning substances such as phosphorus and mercury in the presence of air — and weighed everything both before and after. In every case the weight GAINED by the burning substance exactly equalled the weight LOST by the surrounding air, meaning nothing was actually created or lost overall; the apparent 'weight gain' of the solid was really just oxygen from the air combining with it. This painstaking weighing across many repeated experiments i …