Organic chemistry is easy

Organic chemistry

Inorganic and Organic Chemistry

What are organic compounds? At the beginning of the 19th century, the great Swedish scientist J. J. Berzelius divided the entire field of chemistry into the field of inorganic chemistry and the field of organic chemistry ("living beings" of living nature). Berzelius did not proceed arbitrarily, but examined and compared substances from inanimate nature (metals, salts, mineral acids) and organic compounds (sugar, vinegar, alcohol).

During Berzelius' lifetime it was believed that organic substances were natural substances, i.e. compounds produced by organisms. Although some naturally occurring, inorganic substances had already been artificially produced by synthesis at that time, it was thought that organic compounds could not be built up outside the living organism. The prevailing view was that only through the action of a mysterious one "Life force" (vis vitalis) the formation of organic substances takes place in living beings. It was not possible to produce carbon compounds such as soda or formic acid in the laboratory itself. The thought of a life force was not new. The ancient philosophers of antiquity were already moved by this idea, but immediately rejected it, only to pick it up again.

In the second half of the 18th century, C. W. Scheele began with more detailed investigations into substances that came from animals or plants. In this way he obtained a large number of organic compounds in pure form. He isolated citric acid from lemons, lactic acid from sour milk, and uric acid from bladder stones and discovered that glycerine is a component of animal fats. He soon discovered that all of these "organism-derived" substances consist essentially of carbon, hydrogen, and oxygen. But he did not succeed in determining simple proportional formulas for them. Like many of his colleagues, Scheele also considered these substances to have a particularly complex structure and so it was still believed that they could only be produced by living cells under the influence of a special life force.

This view was then refuted in 1828 by an experiment by a chemist. F. Wöhler succeeded in finding the substance ammonium cyanate (NH4OCN) by heating into the purely organic substance urea. Wöhler repeated his experiments again and again until he was sure that he had produced an organic substance without any vital force. He wrote to his teacher Berzelius:

"... I can't hold my chemical water, so to speak, and I have to tell you that I can make urea without needing kidneys or an animal in general, be it human or dog."

With Wöhler's experiments, the theory of "life force" was refuted for the first time. His experiments also showed that inorganic substances are relatively stable from a chemical point of view, whereas the organic compounds show one low heat resistance, quality Flammability, often slight volatility, a strange one odor and mostly low water solubility.

The demarcation between organic and inorganic chemistry lost more and more of its justification with the refutation of the "life force theory" and the conviction gained acceptance that the same chemical principles apply to organic compounds as to inorganic compounds. Nevertheless, the division of chemistry made by Berzelius is still adhered to today. It turned out that the organic compounds exclusively Carbon compounds are. The common characteristics of organic substances can be traced back to this. The historical term "organic chemistry" in today's sense includes the chemistry of carbon compounds.

Elemental analysis of organic compounds

When analyzing organic compounds in the 19th century, researchers found the elements carbon, hydrogen, oxygen and nitrogen most frequently. They were also able to detect sulfur and phosphorus. However, they rarely found all the other elements. The following experiments are intended to show how certain elements can be detected in organic compounds.

Many organic compounds already carbonize when heated and are therefore as Carbon compounds to recognize.