Analysis:
18 1 1 year, the molecular hypothesis put forward by Italian physics professor avogadro was not taken seriously, let alone recognized. The resulting serious consequences were not foreseen by most chemists at that time.
In the nearly half century before 1860, chemists all over the world were puzzled by atoms and molecules because they did not admit that molecules were the smallest particles that existed independently in a free state or that molecules were composed of atoms. At that time, the work of determining the atomic weight that chemists relied on was also in trouble, and oxygen or hydrogen was often regarded as the relative standard for determining the atomic weight of elements. Because they are not considered diatomic molecules, if the atomic weight is determined by physical methods such as vapor density method, the value will inevitably double. If the atomic weight cannot be determined accurately, the molecular composition can't be determined naturally. Every chemist has his own set of element symbols and chemical formulas, so that in the textbook written by the famous chemist Kekule, the chemical formula of acetic acid competes for as much as 19. This chaotic situation makes many famous chemists even doubt whether the atomic weight can be determined and whether the atomic weight really exists. This is actually questioning atomism. How can such chaotic chemistry continue to develop?
In order to end this chaotic situation and unify everyone's understanding of element symbols, atomic weights, valence and chemical formulas, Kekule and others initiated an international conference of chemists. The conference was held in Karlsruhe, Germany from September 3 to 5, 1860, and 140 chemists mainly from European countries attended the conference. After a heated debate, the meeting failed to reach a unified opinion and had to give up. However, at the end of the meeting, a booklet entitled "Outline of Chemical Philosophy Course" was distributed after the meeting. It is this booklet that makes the problem suddenly clear and quickly unifies everyone's confused understanding. Chemists finally understand that avogadro's molecular hypothesis is the only key to reverse this chaotic situation. The author of this booklet is Italian chemist Nicaro.
Set scientists and revolutionaries in one.
Cornezaro 1826 was born in an executive family in Sicily, Italy on July 26th. He did well in middle school, in which he won a gold medal in arithmetic. /kloc-when he was 0/5 years old, he completed his secondary education and entered the medical department of Palermo University according to his interests at that time. At first, he was interested in all subjects. Later, influenced by Vudra, an academician of the Paris Academy of Sciences and a professor of biology, he became fascinated with physiology. Under the leadership of Vudra. The first subject he studied was the difference between input nerve and output nerve.
At the conference of scientists held in Nablus from 65438 to 0845, his paper on nervous system research was well received by the delegates. At that time, it was necessary to study biology and chemistry experiments. However, the experimental conditions of the medical department are extremely poor, so Conezaro had to go to the teacher's house to do experiments from time to time, and also built a simple laboratory in his own home. The experiment not only cultivated his interest in chemistry, but more importantly, let him discover his lack of chemical knowledge. Since then, his interest has shifted from physiology to chemistry.
Just then, the University of Palermo was in trouble, and Cornezaro was an activist, so he was forced to leave the school. Vudra felt very sorry for this, so he introduced Conezaro to the University of Pisa for further study. In Pisa University, Piria, a chemistry professor, is a knowledgeable and prestigious professor. Shortly after arriving at school, Cornicharo was discovered by Piria as a gifted teenager in the experiment and appointed him as his assistant in the laboratory. In order to gain more systematic knowledge of chemistry, Cornicharo prepared classroom experiments for Professor Piria, and insisted on listening to inorganic chemistry and organic chemistry courses offered by Piria. Experiments and lectures complement each other. Only three years of planned and systematic training made Cornichello a chemist with solid basic knowledge, exquisite experimental skills and brilliant academic thoughts.
Nostalgia made Cornezzaro bid farewell to his beloved teacher Pilia and returned to Palermo in the summer of 1847, when the Sicilian revolutionary movement flourished. As soon as Connie Ricardo Roberto Barreto da Rocha returned to Palermo, she devoted herself to the revolutionary movement and became the backbone of the revolutionary movement like her teacher Vudra. 1848, Sicily's armed uprising against Neapolitan king Ferdinand II officially broke out, which was part of the magnificent European revolution in 1848. After fierce fighting, the rebels drove Ferdinand II out of Sicily and established a temporary revolution. During the battle, Cornichello won the trust of the masses as an artillery commander, was elected as a member of the Sicilian parliament, and Jing was appointed as the secretary of the House of Representatives. The good times didn't last long. The king of Naples rallied troops from several feudal kingdoms around him to fight back. 1April 349, attacked the whole island of Sicily, and the uprising failed. After taking part in the last resistance, Cornichello had to go into exile in France. The restoration dynasty announced that the leaders of the 12 uprising, including Cornichello, were sentenced to death, and Cornichello could not return to his hometown for the time being.
During his half-year wandering in France, he still took time to inspect chemical enterprises in Lyon and other places and learned a lot of knowledge that he could not learn in class. Introduced by Piria and Kahul, a French chemist, he came to work in the laboratory of Xie, a French chemistry professor, where he earnestly carried out experimental research on organic chemistry and fully understood the new progress in the development of organic chemistry at that time.
At that time, Italy was divided into 89 small countries. Although Conezaro can't return to his hometown Sicily for the time being, he still wants to return to Italy and a place closer to his hometown. At this time, there was a country called Piedmont in northern Italy. 1848, supported the Sicilian uprising and had great respect for revolutionaries such as Cornezaro. 185 1 year, Piedmont * * * hired Conezaro as a professor of physics, chemistry and mathematics at the local technical college. The first thing he did when he arrived at the college was to build a chemistry laboratory. Because he has fully realized that it is impossible to create scientific achievements and cultivate scientific talents without chemistry laboratory. It was in this college that he made an important discovery in organic chemistry: aromatic aldehydes reacted with lye to produce corresponding acids and alcohols. This is called Cornezaro reaction in textbooks. This is of great significance in theory and practice.
1855, the most famous university in Piedmont-Genoa University hired him as a professor of chemistry. After busy teaching, he systematically and deeply investigated the development and problems of theoretical chemistry, and the course summary of chemical philosophy was his scientific research achievement during this period.
1860 In April, Sicilian peasants revolted again, and revolutionary fighters including Cornichello returned to Sicily one after another. Ferdinand II was expelled from Sicily again, and Cornichello returned to his hometown 1 1, and became a member of the special committee of Sicily. However, at this time, Cornichello did not forget his scientific career. In September, when the revolutionary work was very busy, he still rushed to Karlsruhe, An Deyu. After reading his pamphlet "Outline of Chemical Philosophy Course", most chemists have since understood and accepted avogadro's molecular hypothesis. Cornezaro, 34, is also recognized as an authority on theoretical chemistry.
Shortly after Conezaro returned from Germany, the kingdom of Naples in Sicily merged with the kingdom of Piedmont to form the kingdom of Italy. By 1870, the kingdom of Italian Emerald unified the whole of Italy. In this revolution to complete national reunification, Konicharo engaged in social and political activities with great enthusiasm in addition to scientific research and teaching. This great scientist was also an outstanding political activist at that time.
The capital of the Kingdom of risorgimento is in Rome. The new regime established Rome University, the highest institution in China. A group of the best Italian scholars gathered here. Of course, Cornichello was the first to be elected. 187 1 year, he came to the university of Rome as a professor of chemistry. In Rome, on the one hand, he engaged in teaching and trained a group of excellent chemists for Italy, on the other hand, he engaged in the research of organic chemistry and made outstanding achievements. In addition, he is a member of Parliament, deputy speaker of the Kingdom of Italy, member of the State Education Commission and the State Finance Commission, and has made outstanding contributions to the construction of a unified Italy.
Demonstrate atomic and molecular theory
In short, he said, Cornezaro demonstrated the theory of atoms and molecules by studying the history of chemistry. His method fully embodies the unity of logic and history. When Konezaro was teaching theoretical chemistry in Genoa, he found the confusion caused by not recognizing avogadro's molecular hypothesis. Faced with this dilemma, he first studied Dalton's atomism, avogadro's molecular hypothesis and its experimental basis. Through this historical investigation, he realized the symptoms of the argument. But to solve this problem, we must master more chemical facts. To this end, he also inspected Bezelius' electrochemical dualism and Duma's criticism of it, summarized the work related to molecular theory done by Duma and other chemists, and analyzed and summarized the chemical theory and some determination methods along historical clues. He solved the following problems that everyone cares about:
1. It is emphasized that avogadro's molecular hypothesis is the natural conclusion of Gay-Lussac's gas binding law, which shows that the molecular hypothesis is well-founded.
2. An important reason why some chemists don't accept avogadro's molecular hypothesis is that they rely too much on Bezayrie's electrochemical dualism. The experimental fact that halogen replaces hydrogen in organic chemistry just proves that electrochemical dualism is incomplete.
3. Explain how to calculate molecular weight by vapor density method according to molecular hypothesis. At the same time, he used gas density to determine the molecular weights of simple materials such as hydrogen, oxygen, sulfur, chlorine, arsenic, mercury and bromine, and water, hydrogen chloride, acetic acid and other compounds.
4. Based on the determination of molecular weight, combined with analytical chemical data, a reasonable atomic weight determination method is proposed. The relationship between avogadro Hypothesis and Duron-Roland Law has also been demonstrated. This law was deduced by French physicists Dulong and Petit in 18 18 through experiments on the relationship between heat capacity and atomic weight of solid single substance.
5. It is pointed out that equivalence is different from atomic weight, which is a quantitative unit for atoms to participate in chemical reactions, and the product of equivalence and atomic valence is atomic weight.
6. According to a large number of experimental data, it is proved that both inorganic chemistry and organic chemistry have only one atomic weight. The laws of chemistry are equally applicable to inorganic chemistry and organic chemistry.
7. The writing principle of chemical formula is determined.
These problems solved by Cornichello clarified many vague and even wrong understandings and cleared the way for the determination of atom-molecule theory. His above viewpoints are the main contents stated in the booklet "Outline of Chemical Philosophy Course".
Like his pamphlet, Cornichello's work was highly praised by his colleagues. Meyer, a German chemist who discovered the periodic law of chemical elements with Mendeleev, read this booklet on his way home from the Karlsruhe conference. He said with emotion: "I am surprised that this short paper explains the most important points in the debate so clearly." The barrier in front of me seems to have peeled off, and many doubts have vanished ... thanks to Cornezaro's brochure. "
Cornicharo's reasonable exposition brings atomism and molecular hypothesis into a coordinated system, so atomism-molecular theory is accepted by chemists. The establishment of atomic and molecular theory directly led to the discovery of the periodic law of chemical elements and the establishment of organic chemistry system.
Cornichello's great contribution to the development of chemistry has made him enjoy a high reputation all over the world. The Royal Society elected him as a member. 1872, the Royal Society awarded him the first special Faraday Medal. 1906 In order to celebrate his 80th birthday, the International Congress of Applied Chemistry was held in Rome. At the meeting, Cornichello was awarded the statue of Bilit symbolizing the transmission of truth. 19 10 May 10, 84-year-old Cornichello died of old age.