Lavoisier showed his genius potential when he was at school. At the age of 20, he won an award from the French Academy of Sciences for his excellent writing on street lighting design in Paris. 1768 was selected as "honorary academician" of French Academy of Sciences.
Summary of Chemistry is a masterpiece left by lavoisier, which marks the birth of modern chemistry.
In this paper, lavoisier described combustion and absorption correctly, and listed the names of chemical elements accurately for the first time in the history of chemistry. The name is based on the fact that matter is made up of chemical elements. Before that, these elements had different names. In the book, lavoisier arranged all the inventions related to chemistry in an orderly way.
Lavoisier's father was a famous lawyer at that time, and his family was superior. Therefore, lavoisier did not immediately become a lawyer, but became interested in botany, and became interested in meteorology while collecting plant specimens in the mountains. Under the recommendation of geologist Gertrude, lavoisier studied and studied chemistry under the famous Parisian chemistry professor Rueller. Since then, lavoisier has forged an indissoluble bond with chemistry.
Lavoisier's first contribution to chemistry was to prove and summarize the law of conservation of mass through experiments. In fact, as early as when lavoisier was born, the versatile Russian scientist lomonosov put forward the law of conservation of mass, which he called "the law of immortality of matter" at that time, which contained more philosophical implications. However, due to the lack of a certain experimental basis, especially in the background of backward Russian science at that time, Europe simply ignored some Russian scientific research achievements, so the law of material immortality has not been widely spread.
The combustion principle is lavoisier's second greatest contribution to chemical research and his most important discovery. Great scientists described the functions of the most important gases: oxygen, nitrogen and hydrogen. He was able to make this discovery because he accurately determined the role of oxygen for the first time. In fact, scientists have confirmed that combustion is a chemical reaction of oxidation, that is, combustion is a combination of matter and a certain gas. Lavoisier named this gas, namely oxygen, which actually means "acid-forming element". Lavoisier finally overthrew the wrong phlogiston theory, which was very popular at that time. According to this statement, any burnt substance will be separated from a substance called phlogiston during combustion. "phlogiston" was once thought to play a leading role in the combustion process.
Lavoisier also correctly named nitrogen. In fact, nitrogen was discovered as early as 1772, but it is called "waste gas" because it is considered as a non-combustible gas, which means "used gas", so it will not be used for combustion. Lavoisier found that this "gas" is actually composed of a gas called nitrogen, because it is "lifeless". Later, he recognized hydrogen, which means "water-forming element" because it is one of the important elements that make up water. He believes that from a chemical point of view, the burning of substances and the breathing of animals belong to the oxidation reaction involving oxygen in the air.
/kloc-in the autumn of 0/772, lavoisier weighed a certain amount of red phosphorus, and after burning and cooling, it was also called measuring the quality of ash, that is, phosphorus pentoxide, and found that the quality had actually increased! He also burned sulfur and found that the quality of ash was greater than sulfur. He thinks it must be some gas absorbed by white phosphorus and sulfur. So he improved the experimental method: put white phosphorus in a bell jar, and there was still some air in the bell jar. The air in the bell jar is connected to the mercury column through a tube to measure the air pressure. When heated to 40℃, white phosphorus burns rapidly and mercury column rises. Lavoisier also found that "1 ounce of white phosphorus can get about 2.7 ounces of white ash. The added weight is basically close to the consumed air weight 1/5 volume. "
Lavoisier's discovery contradicted the phlogiston theory at that time. The phlogiston theory holds that combustion is a decomposition process, and the products of combustion should be lighter than combustible materials. He wrote the experimental results into a paper and submitted it to the French Academy of Sciences. Since then, he has done many experiments to prove that phlogiston is wrong. 1773 In February, he wrote in the experiment record book: "The experiment I did fundamentally changed physics and chemistry." He named the new chemistry "phlogiston chemistry".
1775, lavoisier studied oxygen. He found that the increased mass during combustion was just the decreased oxygen mass. It used to be thought that combustible substances absorbed some air when burning, but in fact they absorbed oxygen and combined with it, which completely overturned the combustion theory of phlogiston.
1777, lavoisier criticized phlogiston and said: "Chemists can only get vague elements from phlogiston theory, which is very uncertain, so they can be used to explain various things at will. Sometimes this element has weight, sometimes it has no weight; Sometimes it is the fire of freedom, and sometimes it is combined with earth elements to form a fire; Sometimes it is said that it can pass through the micropores on the wall of the container, and sometimes it is said that it cannot penetrate; Can be used to explain both alkaline and non-alkaline, transparent and opaque, colored and colorless. It is really a chameleon, changing its face all the time. "
1On September 5th, 777, lavoisier submitted an epoch-making Introduction to Combustion to the French Academy of Sciences, which systematically expounded the oxidation theory of combustion and reversed the phlogiston chemistry. This book was later translated into many languages, gradually eliminating the influence of phlogiston. Since then, chemistry has cut off the connection with ancient alchemy, unveiled the veil of mystery and speculation, and replaced it with scientific experiments and quantitative research. Chemistry thus entered the period of quantitative chemistry, that is, modern chemistry.
Did lavoisier's third contribution to chemistry define the concept of chemical elements according to the four-element theory and three-element theory of ancient Greek philosophers: "If elements represent the simplest components of matter, it may be difficult for us to judge what elements are at present; If, on the contrary, we associate elements with the ultimate concept achieved by current chemical analysis, then all substances that we can't decompose in any way now are elements for us. "
In 1789, the four-year Chemical Summary, lavoisier listed the first table, and the elements were divided into four categories: (1) simple materials, light, heat, oxygen, nitrogen, hydrogen and other material elements. (2) Simple nonmetallic substances, such as sulfur, phosphorus, carbon, hydrochloric acid, hydrofluoric acid, boric acid, etc. Its oxide is acid. (3) Simple metallic substances, such as antimony, silver, bismuth, cobalt, copper, tin, iron, manganese, mercury, molybdenum, nickel, gold, platinum, lead, tungsten and zinc. Oxidized into base, which can neutralize acid. (4) Simple materials, such as lime, magnesium oxide, barium, bauxite and silica.