Jacob Vant-Hoff

Vant-Doroff received the first Nobel Prize in Chemistry for the opening of the laws of chemical dynamics and osmotic pressure. This high award was noted the importance of the young region of science -physical chemistry.

The scientist who used generally respect, a member of the fifty-two scientific societies and academies, an honorary doctor of many higher educational institutions, Want-Hoff left after himself a number of fundamental theories, which in our days have a continuing value for chemistry. Presentations, ideas and views of the scientist played a big role in the development of the basics of modern mineralogy, as well as for the development of biology. In the history of science, Vant-Hoff went as one of the founders of stereochemistry, the teachings on chemical equilibrium and chemical kinetics, the osmotic theory of solutions and chemical geology.

Jacob Henrik Want-Hoff was born on August 30, 1852 in the Netherlands, in Rotterdam, in the doctor's family. Members of this family were repeatedly chosen by burgomistraces, occupied other elected positions in urban self-government.

Already in the elementary school, the teacher was noticed by the boy love for music and poetry. In the future, he showed remarkable abilities to accurate natural sciences. At the end of the school in 1869, Jacob entered the Polytechnic in Delft. And here it is significantly superior to his fellow students in terms of knowledge and because in 1871, without an entrance exam was admitted to Leiden University. Later in this university, Vant-Hoff ended up the candidate exam.

But in Leiden he did not like it, and he went to Bonn to the famous Chemist Kekule. After the opening of a young propionic acid scientist, Kekule recommended his student to go to Paris to Professor Würtz, a specialist in organic synthesis.

In Paris, Jacob became close to the French chemist-technologist Joseph Ashil Le Belem. Both of interest was followed by research in the field of optical isomerism, which spent Paster.

In December 1874, Vant-Hoff defended his doctoral dissertation at the University of Utrecht and in 1876 began teaching activities in a local veterinary school. In the autumn of 1874, he published a small work with a long title in Utrecht: "Proposal to apply modern structural chemical formulas in the space together with the notes on the attitude between the optical rotational ability and the chemical constitution of organic compounds."

Vant-Hoff introduced the situation into science, which allowed from new positions to consider the structure of chemical compounds. The representation that in the methane molecule four hydrogen atoms are evenly distributed in space and therefore we can talk about the tetrahedral form of the molecule, returns us to the goggles of Kekule. In the model proposed model, the models four valence of the carbon atom are directed to the tops of the tetrahedron, in the center of which this atom is located. Using such a model, Vant-Hoff suggested that due to the connection of atoms or atomic groups with carbon, the tetrahedron may be asymmetric, and expressed an idea of \u200b\u200ban asymmetric carbon atom. He wrote: "In the case when the four affinities of the carbon atom are saturated with four different monovalent groups, you can get two and only two different tetrahedra, which are a mirror reflection one of the other and mentally cannot be combined, that is, we are dealing with two structural Formulas in space. "

New article Want-Gooff "Chemistry in space" (1875), where he expressed all these considerations, served as the beginning of a new stage in the development of organic chemistry. Soon he received a letter from Professor Vistartenus, one of the most famous specialists in this area: "I would like to consent to the translation of your article into German by my assistant Dr. Herman. Your theoretical development gave me greater joy. I see it not only an extremely witty attempt to explain still incomprehensible facts, but I also believe that it is in our science ... will acquire an orphanage. "

The translation of the article was published in 1876. By this time, Vant-Hoff received a place of physics assistant in the veterinary institute in Utrecht.

A large role in popularizing new looks of Vant-Gooff was unwittingly, Professor G. Kolbe from Leipzig. In a sharp shape, he expressed his comments on the article of the Dutch scientist: "Some doctor Ya.G. Vant-Hoff from the veterinary institute in Utrecht apparently does not have taste for accurate chemical research. It is much easier for him to restore the Pegasus (probably brought to the veterinary institute) and proclaim in its "chemistry in space", which seemed to him during a bold flight to the chemical Parnassa, atoms are located in the interplanetary space. " Naturally, everyone who read this sharp reward, interested Vant-Gooff theory. So it began its rapid spread in the scientific world. Now Want-Hoff could repeat the words of his idol Byrona: "Once in the morning I woke up a celebrity." A few days after the publishing article, Kolba Want-Gooff proposed the position of the teacher at the University of Amsterdam, and since 1878 he became a professor of chemistry.

From 1877 to 1896, Vant-Hoff was a professor of chemistry, mineralogy and geology in shortly before that, founded by Amsterdam University. Always next to him was his wife for women Want-Gooff Mees. She managed to do not only with the house and children, but also managed to create his husband a real creative atmosphere.

The interests of Vant-Gooff to the search for the most common patterns again manifested themselves in its great work "views on organic chemistry." But soon the scientist moved to the study of chemical dynamics. He outlined his views on this issue in the book "Essays on Chemical Dynamics" (1884).

Vant-Doroff has developed a doctrine of the reaction rate and thereby created the founding of the chemical kinetics. It determined the reaction rate as a natural, but not always a uniform change in the concentration of reacting substances per unit of time. He managed to formulate this pattern in general mathematical form. The establishment of the dependence of the reaction rate from the number of interacting molecules, as well as closely associated with this, the new representations of the Vant-Gooff on the nature of chemical equilibrium significantly contributed to the significant progress of theoretical chemistry.

At the same time, it was found that the chemical equilibrium considered by the Vant-Muffa as a result of two oppositely directed reactions that are at the same speed (reversible process) depends on temperature. The ideas about the chemical equilibrium Want-Hoff associated with the two principles of thermodynamics already known at that time. The most important result of this work was the conclusion of the Vant-Gooff of the mathematical formula, in which the interrelation of temperature and heat reaction with the equilibrium constant was reflected. This pattern is now known as the Equation of the reaction isoocardly derived by the Vant-Gooff.

Another major contribution of Vant-Gooff to theoretical chemistry during the Amsterdam period of its activities was the opening of analogy of osmotic and gas pressure. Based on the empirical patterns formulated, empirical patterns on the increase in the boiling point and lowering the freezing point of Vant-Hoff solutions in 1885 developed a osmotic theory of solutions.

C. Manolov tells in his book as a scientist came to this discovery: "Why not submit a system in osmometer" Water - a semi-permeable partition - solution "in the form of a cylinder with a piston? The solution is located at the bottom of the cylinder, the piston is a partition, and above it is water. This is the main method of thermodynamics. The principles of gas thermodynamics also apply to the properties of dilute solutions. "

Want-Doroff drew a cylinder with a piston, in space under the piston he wrote "solution", and above the piston - "water". The arrows directed from the solution to water showed that there is a pressure in the solution, which seeks to raise the piston up.

"First, it is necessary to calculate what kind of work is required so that the piston under the action of osmotic pressure moves up, but on the contrary, it is possible to find out what kind of work is needed to return the piston down, overcoming osmotic pressure."

Vant-Hoff spent mathematical calculations, filling the leaf by formulas, and here it is the end result!

"Incredible! Dependence is exactly the same as for gases! The expression is absolutely identical to the Klapairon-Clausius equation! " Want-Hoff took the sheet and repeated all the calculations. "The same result! Osmotic pressure laws are identical to gas laws. If the constant has the same value, then you can consider the molecules of the diluted matter as the gas molecule, presenting that the solvent is removed from the vessel. The constant can be calculated according to Pffer. He again took a notebook, and the feather quickly rolled through paper. For sugar solutions, the constant had the same meaning as the gas constant. The analogy was complete. "

Vant-Doroff found that dissolved molecules produce osmotic pressure equal to the pressure that would have the same molecules if they were taken in a gaseous state an amount equal to the volume of the solution. This fundamental discovery showed the unity of the laws of physics and chemistry (although the causes of osmotic pressure were not opened).

Want-Hoff also had a great influence on the further development of the theory of dissociation, having studied in its work "Chemical equilibrium in gases and dilute solutions" (1886).

In March 1896, Vant-Hoff left Amsterdam, moved to Berlin at the invitation of the Prussian Academy of Sciences. In accordance with the proposal of Max Planck and Emil Fisher for Vant-Gooff, a special research laboratory was created at the Academy of Sciences, and the scientist himself was immediately elected by its actual member and honorary professor of the University of Berlin.

In Germany, he conducted extensive experimental and theoretical work that helped to establish the conditions for the formation of potash salts deposits and create rational technology for their recycling.

The scientist was in America, when he learned that he received the first Nobel Prize in Chemistry "In the recognition of the enormous importance of the opening of the laws of chemical dynamics and osmotic pressure in solutions." December 10, 1901 in Stockholm gathered outstanding scientists in the world. The solemn ceremony in the festive illuminated hall of the Swedish Academy of Sciences was really unforgettable.

In the evening, the Want-Hoff banquet was able to express his heart gratitude for the greatest honor, which he was honored, the Committee on Nobel Prizes in the field of chemistry and his chairman, Professor P. Kleve.

Presenting a scientist on behalf of the Swedish Royal Academy of Sciences, S.T. The dress called the scientist the founder of stereochemistry and one of the creators of the chemical dynamics, and also stressed that Want-Gooff research "made a significant contribution to remarkable achievements of physical chemistry."

In the following days, according to the requirements of the Nobel Committee, awarded should have been reported on scientific achievements for which they were awarded to the award. Want-Hoff in his lecture spoke of the theory of solutions.

The scientist continued to work, but a long-standing severe disease was prevented by Vant-Hoff deeper to study the synthetic effect of enzymes in a living plant organism.

Vant-Gooff

(1852- 1911)

Netherlands chemist, one of the founders of the physical theory of chemistry and stereochemistry, Jacob Vant - Hoff was born on August 30, 1852 in Rotterdam in the doctor's family.
In 1869, Vant - Hoff finished high school. And although he dreamed of a chemist since childhood, but because of the desire of his parents, began to study the engineering business and even worked for some time on a sugar factory.
In 1871, Vant - Hoff went on the natural and mathematical faculty of Leiden University, then moved to the Bonn University to study chemistry. Want-Hoff improved his knowledge in Paris, after a while he returned to the Netherlands and in 1874 p. He defended his doctoral dissertation in Chemistry in Utrecht University.
The development of the scientific career of Jacob went very slowly, although it was the first one (in 1874-1875) developed the theory of spatial placement of atoms in organic compound molecules, which was soon based on the basis of modern stereochemistry. Only in 1876. He took the position of lecturer physics in the Royal Veterinary School in Utrecht. In 1878 Want - Hoff becomes a professor of theoretical and physical chemistry in the University of Amsterdam. In the same year, Jacob Vant - Hoff married the daughter of the Rotterdam merchant Johann Francine Mees. This happy couple had two daughters and two sons.
In 1896, Vant - Hoff moved to the post of professor of experimental physics in Berlin University, where he had a fully equipped laboratory, and at the same time, the opportunity to study research activities.
As a result of its studies, Vant -Hoff brought one of the main equations of thermodynamics - the isochor equation, as well as the formula for the dependence of the chemical method from the equilibrium constant of the chemical reaction at constant temperatures, that is, the isotherm equation. He developed the theory of divorced spokes, based on the analogy between substances in the gas-like and soluble states, expanded the law of ideal gases on divorced solutions and brought the law of osmotic pressure (the law of VANT - Goff). In 1890, introduced the concept of solid solutions, using his ideas to solid bodies.
In 1901, Vant - Hoff became the first laureate of the Nobel Prize in Chemistry as a sign of recognition of the enormous importance of the opening of the law of osmotic pressure in solutions.
In addition to the Nobel Prize, Want - Hoff was awarded the medals of scientific societies of different countries, was a member of the European and American Chemical and Academies of Sciences, he was awarded to the steps of universities in Great Britain and America.

The dependence of the flow rate of the chemical reaction from the temperature is determined by the Rule-Hoff rule.

Dutch Chemist Vant-Gooff Jacob Hendrik, the founder of stereochemistry, in 1901 became the first laureate of the Nobel Prize in Chemistry. She was awarded him for the opening of the laws of chemical dynamics and osmotic pressure. Want-Hoff introduced the ideas about the spatial structure of chemicals. He was confident that progress in fundamental and applied studies in chemistry can be achieved by applying physical and mathematical methods. Developing the doctrine of the reaction rate, he created chemical kinetics.

Chemical reaction rate

So, the kinetics of chemical reactions is called the doctrine of the flow rate, which chemical interaction occurs in the process of reactions, and the dependence of reactions from various factors. In various reactions, the rate of leakage is different.

Chemical reaction rate Directly depends on the nature of the chemicals that react. Some substances such as NAON and HCl are able to respond for a split second. And some chemical reactions last for years. An example of such a reaction is iron rusting.

The reaction rate also depends on the concentration of reacting substances. The higher the concentration of reagents, the higher the reaction rate. During the reaction, the concentration of reagents decreases, therefore, slows the reaction rate. That is, at the initial moment, the speed is always higher than in any subsequent.

V \u003d (C Kon - with Nach) / (t con - t nach)

Concentrations of reagents are determined at certain intervals.

Want-Gooff rule

An important factor on which the reaction rate depends is the temperature.

All molecules are faced with others. The number of collisions per second is very large. But, nevertheless, chemical reactions do not proceed with a huge speed. This is happening, because during the reaction the molecule should collect in the activated complex. And only active molecules whose kinetic energy can have enough for this can form it. With a small amount of active molecules, the reaction proceeds slowly. With a rise in temperature, the number of active molecules is increasing. Therefore, the reaction rate will be higher.

Want-Hoff believed that the rate of chemical reaction is a natural change in the concentration of reacting substances per unit of time. But it is not always uniform.

The rule of Vant-Gooff states that with increasing temperature for every 10 o, the speed of the chemical reaction increases 2-4 times .

Mathematically, the Vant-Gooff rule looks like this:

where V 2. T 2., but V. 1 - rate of reaction during temperature t 1;

ɣ - temperature coefficient of reaction rate. This coefficient has a ratio of speeds of speeds at temperatures t + 10. and t..

So, if ɣ \u003d 3, and at 0 o with the reaction lasts 10 minutes, then at 100 ° C. It will continue only 0.01 seconds. A sharp increase in the rate of flow of a chemical reaction is explained by increasing the number of active molecules when increasing the temperature.

The Vant-Gooff rule is applicable only in the temperature range of 10-400 o C. Do not obey the rule of Vant-Gooff and the reaction in which large molecules are involved.

The first Nobel Prize in Chemistry was received in 1901. Jacob Heinrich Vant-Hoff for the opening of the laws of chemical dynamics and osmotic pressure. This high award was noted the importance of the young field of science - physical chemistry.

Already in the first works, Vant-Hoff has led provese evidence: only the use of physical and mathematical methods can provide progress in fundamental and applied chemistry studies. The emergence of new domains of knowledge, such as stereochemistry, has become possible only in close connection with other areas of natural science. Vant-Hoff became the founder of stereochemistry. He made new views against all incorrect views of the Yarya agnostics and narrow-minded empirics and introduced into the chemistry of representation of the spatial structure of substances.

Want-Hoff was born on August 30, 1852 in Rotterdam in the doctor's family. The genus of Vant-Gooff over a number of generations belonged to the estate near the Dutch city of Dortrecht. The members of this family for many decades were burgomistraces or occupied other elected positions in urban self-government.

Already in the elementary school, the teacher noticed the love of music and poetry in the young Want-Gooff. In the future, he showed remarkable abilities to accurate natural sciences. At the end of the school in 1869, the future scientist entered the Polytechnic in Delft. During the years of teachings, Vant-Hoff is particularly interested in differential and integral calculations, which at that time attracted their close attention of many.

Then Vant-Hoff became interested in philosophy. He thoroughly studied the "Course of Positive Philosophy" O. Konta, in which he drew attention to the path, leading to a rational study) in chemistry. Want-Hoff understood the statement of contractions as a way of logical improvement of chemical knowledge. But Vant-Hoff did not perceive either the hostitity of the right to the theory, nor its limited mechanistic methodology. On the contrary, Want-Hoff recognized the need for the unity of theory and practice; He never adhered to a one-sided empirical point of view, and later defended his materialistic ideas from "energy" Ostvalda.

In the Polytechnic of Delft, Vant-Hoff in terms of knowledge significantly exceeded its fellow students and because in 1871, without an entrance exam was admitted to Leiden University. Later in this university, Vant-Hoff ended up the candidate exam. In addition to interest in mathematics, "Old Love for Chemistry" broke out again, and Vant-Hoff continued its chemical education in the most famous centers of this science - in the laboratories of Kekule in Bonn and Würtz in Paris. At this time, Kekule is the author of the theory of the Benzol structure and the creator of ideas about the location of atoms in molecules - was considered one of the leading experts in the field of fundamental problems of chemistry. The admiration of the personality of this scientist and his works caused interest in the study of the structure of molecules at Want-Gooff. But Vant-Hoff long stayed in Bonn. Working in Nurez in Paris, he met Le Belem, who simultaneously with Vant-Hoff and independently of him created a known tetrahedral model of a carbon atom based on the representations of a beechule on the spatial arrangement of atoms in the molecule.

In December 1874, Vant-Hoff defended his doctoral dissertation at the University of Utrecht and in 1876 began teaching in the local veterinary school. In the fall of 1874, he published a small work with a long title in Uttrech: "Proposal to apply modern structural chemical formulas in the space together with notes on the attitude between the optical rotational ability and the chemical constitution of organic compounds" 37. Neither this work published in Dutch nor the translation into French (Rotterdam, 1875) did not attract the attention of chemists. Genuine fame came after Vistrooms - a decisive supporter of the new science of stereochemistry 38 - introduced scientists in 1877 with the German translation of this strongly reworked article by Vant-Gooff, now named "Location of atoms in space". This translation was published with the preface of Vistartenus 39.

Vant-Hoff introduced the situation into science, which allowed from new positions to consider the structure of chemical compounds. The representation that in the methane CH 4 molecule 4 four hydrogen atoms are evenly distributed in space and therefore we can talk about the tetrahedral form of the molecule, returns us to the groces of Kekule 40. They were reflected in the model proposed model: the four valence of carbon atom are directed to the tops of the tetrahedron, in the center of which this atom 41 is located. Using such a model, Vant-Hoff suggested that due to the connection of atoms or atomic groups with carbon, the tetrahedron may be asymmetric, and expressed an idea of \u200b\u200ban asymmetric carbon atom. He wrote: "In the case when the four affinities of the carbon atom are saturated with four different monovalent groups, you can get two and only two different tetrahedra, which are a mirror reflection one of the other and mentally cannot be combined, that is, we are dealing with two structural Formulas in space "42.

The phenomena of optical isomerism could not be understood using the structural formulas that existed at the time. The remarkable achievement of Vant-Gooff was the establishment of a communication between the presence in the compound of an asymmetric carbon atom and the optical isomerism of the substance. The Dutch scientist considered indisputable that both optical isomers correspond to two molecular models with a mirror symmetry relative to the asymmetric carbon atom. Consequently, each optically active compound contains an asymmetric carbon atom. This assumption could easily be checked experimentally, Want-Hoff confirmed its hypothesis about the existence of spatial structural formulas in experimental study of numerous optically active compounds.

In this work, Vant-Hoff also explained another kind of isomerism, which Vistrooms called "geometric isomeria". Such, for example, isomerism of fumaroic acids ( trance-Butendicarbonova) and Maleinova ( cis-Butendicarbonova). Their structural formulas are the same, and properties are different. To explain this phenomenon, the vant-huff was again used a tetrahedral model of carbon atom, thereby tied the spatial structure and chemical properties of substances. So again proved the importance of mental models in chemistry.

Despite the study of the philosophy of contact, Want-Hoff was a materialist and a spontaneous dialectic. With their performances and the results of research, Vant-Hoff successively defended the atomic molecular teachings from the attacks of idealist philosophers, and in the 90s and from supporters of Energy Energy. The strongest blow to the idealism caused the discovery of the Vant-Gooff stereochemistry. Back in 1871, Ernst Makh presented numerous and, in his opinion, irrefutable arguments that "the chemical elements cannot exist in the space of three zeros." Vant-Hoff made both against these idealistic allegations and against the views of Kolle, expressed in the reviews on the work of Vant-Gooff.

Herman Colbe (1818-1884); The author of numerous articles in published under his editors "Journal of Practical Chemistry"; in which he opposed the stereochemical ideas of Vant-Gooff

In 1877, soon after the release of the German translation of the article by Vant-Gooff Kolbe in a rough polemic form, wrote: "Someone Dr. Ya. G. Vant-Gooff, who occupies a position in the veterinary school of Utrecht, obviously not to taste accurate chemical research. He found more pleasant Sit on the Pegasus (probably brought from the veterinary school) and tell the world to the fact that a progress from the chemical Parnass in its grind flight-arrangement of atoms in the world space "43. In another place of the Colbe article, we read: "It is noteworthy for our time, poor critics and hate criticism that two almost unknown chemists, one of which works in a veterinary school, and the other - in the Agricultural Institute 44, are discussing one of the most complex problems of chemistry with confidence which, perhaps, does not solve anyone: the question of the location of atoms in space - and the explanations are given with such audacity, which simply discourages genuine natural scientists. "

The disbelief in the possibility of knowledge of the world, contempt for theoretical thinking, dialectics and materialism led Kolbe to the fight against advanced ideas in natural science. The stereochemical views of the Vant-Gooff gradually received confirmation and use not only in organic chemistry 45, but after 20 years and in inorganic chemistry 46. The ratios set for an asymmetric carbon atom were successfully used in 1890 by Alfred Werner to explain the cases of isomerism in an asymmetric nitrogen atom.

From 1877 to 1896, Vant-Hoff was a professor of chemistry, mineralogy and geology in shortly before that of the University of Amsterdam. There he fulfilled many valuable theoretical work. At the same time, Vant-Hoff managed to happily combine courage in nominating ideas and thoroughness of their development. The work of Vant-Gooff has shown that the study of fundamental chemical patterns is a process that requires not only perseverance, but also fantasies. In the lecture, read by Vant-Goff, when joined the post of professor at Amsterdam University, the scientist said that without the "fantasy in science" neither the preparation of the experiment, nor the explanation of the results obtained. To explore this issue, Vant-Hoff has read more than two hundredths of the lives of mathematicians and naturalists. This style of work admired students and friends of Vant-Gooff.

The interests of Vant-Gooff to the search for the most common patterns were again manifested in its great work "views on organic chemistry" (t. I-II, 1878-1881). Based on the ideas about the asymmetric carbon atom, he wanted to disclose the most common patterns of relations between the structure and the chemical properties of organic compounds. However, the solution of these issues at that time prevented obviously insufficient knowledge of the structure of atoms and molecules. Even in our many problems, important for the theoretical foundations of organic chemistry, have not yet been resolved.

Want-Hoff soon moved to the study of chemical dynamics; Later, he outlined his views on this issue in the book "Essays on Chemical Dynamics" 47 (1884). Dutch physicochemist developed the doctrine of the reaction rate and thereby created the founding of the chemical kinetics. It determined the reaction rate as a natural, but not always a uniform change in the concentration of reacting substances per unit of time. He managed to formulate this pattern in general mathematical form. The establishment of the dependence of the reaction rate from the number of interacting molecules, as well as closely associated with this, the new representations of the Vant-Gooff on the nature of chemical equilibrium significantly contributed to the significant progress of theoretical chemistry.

At the same time, it was found that the chemical equilibrium considered by the Vant-Muffa as a result of two oppositely directed reactions that are at the same speed (reversible process) 48 depends on temperature. The ideas about the chemical equilibrium Want-Hoff associated with the two principles of thermodynamics already known at that time. The most important result of this work was the conclusion of the Vant-Gooff of the mathematical formula, which reflects the relationship between the temperature and heat of the reaction with the equilibrium constant. This pattern is now known as the Equation of the Reaction Range 49 derived by the Vant-Gooff.

In the development of teachings on chemical equilibrium on a thermodynamic basis, a significant role was played by the research of the lessel, Gorestman and Gibbs.

One of the most significant discoveries of this time was to establish the nature of the driving force of the reaction - chemical affinity. This concept was not exactly defined 50. Tomsen in 1854 and Bertlo in 1868 tried to do this, but success did not achieve 51.

Want-Hoff in 1885 expressed the idea that the operation of the affinity could serve the operation of the reaction, and led the mathematical expression 52 for her. However, it did not enter the equilibrium constant from the law action of masses, formulated in general, in 1867 Guldberg and Vaiga based on the idea of \u200b\u200bthe probability of collision with each other reacting molecules. In 1885, Vant-Gooff managed to withdraw this law to thermodynamically, which immediately increased the possibility of its practical application.

The last major contribution of Vant-Gooff to theoretical chemistry during the Amsterdam period of its activity was the opening of an analogy of osmotic and gas pressure. Based on the empirical patterns formulated by Raul on increasing the boiling point and lowering the freezing point of Vant-Hoff solutions in 1885, developed an osmotic theory of solutions. It showed an analogy of the behavior of dissolved substances and gases and found that the equation of the state of ideal gases PV \u003d RT when it was used to describe the osmotic pressure in solutions, it has a form pV \u003d IRT (I\u003e 1 - coefficient characterizing the deviation of the behavior of some substances) 53, osmotic pressure The solutions were first measured in 1877 by the Botany Pfferfer, which used artificially prepared semi-permeable membacins 54. Want-Hoff could understand that this phenomenon is characteristic in general for chemical processes. Want-Hoff has established that dissolved molecules produce osmotic pressure equal to the pressure that would have the same molecules if they occupied a volume equal to the volume of the solution in the gaseous state. Such an explanation was given by the found pfferper high values \u200b\u200bof osmotic pressure 55. This fundamental discovery showed the unity of the laws of physics and chemistry (although the causes of osmotic pressure were not opened).

Want-Hoff also had a great influence on the further development of the theory of dissociation, having studied in its work "chemical equilibrium in gases and diluted solutions" (published in Stockholm in French in 1886.56) the nature of the dependence between the decrease in the freezing temperature of the solvent, the vapor pressure mortar and osmotic pressure of salts, acids and bases.

Together with Wilhelm Ostvald Vant-Hoff began to publish a magical chemistry magazine since 1887. In the first issue of this magazine, except for the Want-Gooff article, the work was also published by the work of Arrhenius, in which the views of the Dutch scientist were also confirmed and developed.

In 1890, Vant-Hoff formulated the concept of solid solutions 57.

In March 1896, Vant-Hoff left Amsterdam, moved Berlin at the invitation of the Prussian Academy of Sciences. In accordance with the proposal of Max Planck and Emil Fisher, a special research laboratory at the Academy of Sciences was created for Vant-Gooff, and the scientist himself was immediately elected by its actual member and honorary professor of the University of Berlin. In Berlin, he conducted extensive experimental and theoretical works that helped establish the formation of the formations of potash salts and create a rational technology for processing such substances. The results of these studies (conducted from 1897 to 1903) were published in two issues (1905 and 1909) under the title "to the formation of oceanic salt deposits" 58.

Want-Gooff's old heavy disease prevented it deeper to study the synthetic effect of enzymes in a living plant organism. The forecast made by scientists in 1900 "Chemist will reach its synthesis to a cell, which as an organic matter is now being studied by biologists," brilliantly confirmed today. It was this task that the specialists in a new area of \u200b\u200bresearch, which is being developed jointly by chemists and biologists.

The scientist who enjoyed by general respect, a member of the fifty-two scientific societies and academies 59, the first laureate of the Nobel Prize in Chemistry (1901), Cavalier of Medals Davy, Helmholtz and other, Prussian Order "For Merit in Sciences and Arts", Honorary Doctor of Many Higher Educational institutions, Want-Hoff left after himself a number of fundamental theories, which in our days have a continuing value for chemistry. Representations, ideas and views of Vant-Gooff played a big role in the development of the basics of modern mineralogy, as well as for the development of biology. In the history of Science, Vant-Hoff went as one of the founders of stereochemistry, the teachings on chemical equilibrium and chemical kinetics, the osmotic theory of solutions and chemical geology 60.

Netherlands Chemist Jacob Hendrik Want-Hoff was born in Rotterdam, in the family of Alida allegedly (Colf) Want-Gooff and Jacob Hendrik Want-Gooff, a doctor and a Cognot of Shakespeare. He was the third child from seven children born. His first chemical experiments V.G., student of the Rotterdam City secondary school, which he graduated in 1869, put at home. He dreamed of a chemist career. However, parents, considering the research work unpromising, persuaded the Son to begin to study the engineering business in the Polytechnic School in Delft. In her V.-g. For two years, a three-year training program passed and the exhaust exam was best passed. In the same place, he became interested in philosophy, poetry (especially works by George Bairon) and mathematics, the interest in which he carried through the whole life.

Having worked for short time at the sugar factory, V.-g. In 1871 he became a student of the Natural-Mathematics Faculty of Leiden University. However, the next year he switched to Bonn University to study chemistry under the leadership of Friedrich Augustus Kekule. Two years later, a future scientist continued his classes at the University of Paris, where she completed his work on the dissertation. Returning to the Netherlands, he presented it to the defense in Utrecht University.

At the very beginning of the XIX century. French physicist Jean Batiste Bio noticed that the crystalline forms of some chemicals can change the direction of the rays of polarized light passing through them. Scientific observations also showed that some molecules (they were called the optical isomers) rotate the plane of light in the direction opposite to the one in which other molecules rotate, although the first, and the second are the molecules of the same type and consist of the same number of atoms. Observing this phenomenon in 1848, Louis Paster put forward a hypothesis that such molecules are a mirror mapping of each other and that atoms of such compounds are located in three dimensions.

In 1874, a few months before the defense of the thesis, V.-g. Published an article on 11 pages called "Proposal to apply modern structural and chemical formulas in the space together with a note on the attitude between the optical rotational ability and the chemical design of organic connections" ("An Attempt to Extend to Space The Present Structural Chemical Formulae. WITH AN OBSERVATION ON The Relation Between OptiCal Activity and The Chemical Constituents of Organic Compounds ").

In this article, he suggested an alternative for two-dimensional models, which at that time were used to image the structures of chemical compounds. V.-G. suggested that the optical activity of organic compounds is associated with an asymmetric molecular structure, and the carbon atom is in the center of the tetrahedron, and in four corners there are atoms or groups of atoms that differ from each other. Thus, the interchanges of atoms or groups of atoms located in the corners of the tetrahedra can lead to the appearance of molecules identical to the chemical composition, but are a mirror image of each other in structure. This explains the differences in optical properties.

Two months later, in France, it came to the same conclusion that he worked on this problem independently of V.-g. His comrade in the University of Paris Joseph Ashil Le Bel. By distributing the concept of a tetrahedral asymmetric carbon atom on compounds containing carbon-carbon dual bonds (general edges) and triple bonds (general faces), V.-g. It argued that these geometric isomers are generalized the edges and verge of tetrahedra. Since the theory of Want-Gooff - Le Bely was extremely contradictory, V.-g. I did not dare to present it as a doctoral dissertation. Instead, he wrote the dissertation on cyanoacetic and malonic acids and in 1874 received a doctoral degree in chemistry.

Considerations V.-G. The asymmetric carbon atoms were published in the Dutch magazine and did not make a big impression until two years later the article was translated into French and German. First, the theory of Vant-Gooff - Le Bely washed by famous chemists, such as A.V. Herman Kolbe, who called it "fantastic nonsense, completely devoid of any actual foundation and a completely incomprehensible serious researcher." However, over time, it was based on modern stereochemistry - the field of chemistry, which studies the spatial structure of molecules.

Formation of scientific career V.-g. went slowly. Initially, he had to give private lessons and physics on announcements, and only in 1976 he received the position of lecturer physics in the Royal Veterinary School in Utrecht. Next year, he becomes a lecturer (and later professor) theoretical and physical chemistry of the University of Amsterdam. Here, over the next 18 years, he read five lectures on organic chemistry every week and for one lecture on mineralogy, crystallography, geology and paleontology, and also led the chemical laboratory.

Unlike most of the chemists of their time V.-g. had solid mathematical training. It was useful to a scientist when he took up the complex task of studying the speed of reactions and conditions affecting a chemical equilibrium. As a result of the work done V.-G. Depending on the number of those involved in the reaction, the molecules classified chemical reactions as monomolecular, bimolecular and multi-molecular, and also determined the order of the chemical reaction for many compounds.

After the occurrence of chemical equilibrium in the system with the same speed flows and straight, and inverse reactions without any finite transformations. If the pressure increases in such a system (the conditions or concentration of its components are changed), the equilibrium point shifts so that the pressure decreased. This principle was formulated in 1884 by the French chemist Henri Louis Le Chatel. In the same year V.-G. The principles of thermodynamics applied in the formulation of the principle of moving equilibrium resulting from a temperature change. At the same time, he introduced the generally accepted designation of reaction reversibility with two arrows directed in opposite sides. The results of their research V.-g. Outlined in "Essays on Chemical Dynamics" ("Etudes de Dynamique Chimique"), published in 1884

In 1811, the Italian physicist Amedeo Avogadro found that equal volumes of any gases at the same temperature and pressure contains the same number of molecules. V.-G. It was concluded that this law is fair and for dilute solutions. The discovery made them was very important, since all chemical reactions and exchange reactions inside the living beings occur in solutions. The scientist also experimentally found that the osmotic pressure, which is a measure of the desire of two different solutions on both sides of the membrane to the alignment of the concentration, depends on the concentration and temperature in weak solutions and, therefore, is subject to gas laws of thermodynamics. Conducted V.-G. The studies of diluted solutions were justified by the theory of electrolytic dissociation of the Sevante Arrhenus. Subsequently, Arrhenius moved to Amsterdam and worked together with V.-G.

In 1887 V.-g. And Wilhelm Ostvald took an active part in the creation of a "magazine of physical chemistry" ("Zeitschrift Fur Physikalische Chemie"). Ostvald shortly before that took the vacant place of professor at the Chemistry of the University of Leipzig. V.-G. Also offered this position, but he rejected the proposal, as the University of Amsterdam declared his readiness to build a scientist a new chemical laboratory. However, when V.-G. It became obvious that pedagogical work carried out in Amsterdam, as well as the execution of administrative duties hinder his research activities, he accepted the proposal of the University of Berlin to take the place of professor of experimental physics. It was stipulated that here he will lecture only once a week and a fully equipped laboratory will be given at his disposal. It happened in 1896

Working in Berlin, V.-g. It was engaged in the use of physical chemistry to solve geological problems, in particular when analyzing oceanic salt sediments in Stasfurt. Prior to World War, these sediments almost completely ensured carbon dioxide production of ceramics, detergents, glass, soap and especially fertilizers. V.-G. It also began to engage in biochemistry problems, in particular, the study of enzymes that serve as catalysts for chemical changes necessary for living organisms.

In 1901 V.-g. He became the first laureate of the Nobel Prize in Chemistry, which was awarded him "as a sign of recognition of the enormous importance of the opening of the laws of chemical dynamics and osmotic pressure in solutions." Presenting V.-g. On behalf of the Swedish Royal Academy of Sciences, S.T. Odaer called the scientist the founder of stereochemistry and one of the creators of the doctrine of chemical dynamics, and also stressed that research V.G. "They made a significant contribution to the wonderful achievements of physical chemistry."

In 1878 V.-g. Married to the daughter of the Rotterdam merchant Johanne Francine Mees. They had two daughters and two sons.

Throughout his life, V.-g. carried a living interest in philosophy, nature, poetry. He died from the pulmonary tuberculosis on March 1, 1911 in Germany, in Steglice (now this is part of Berlin).

In addition to the Nobel Prize, V.-g. The Medal of Davie London Royal Society (1893) and the Medal of the Helmholtz Prussian Academy of Sciences (1911) was awarded. He was a member of the Netherlands Royal and Prussian Academies of Sciences, British and American Chemical Societies, the American National Academy of Sciences and the French Academy of Sciences. V.-G. Honorary degrees of Chicago, Harvard and Yale Universities were assigned.