Part I. Chemistry of organic compounds text 1. Organic chemistry. Introduction

Organic chemistry is concerned with substances containing carbon. The number of known carbon compounds, or organic compounds, exceeds two millions, whereas inorganic substances number 50 thousands. Carbon may thus be singled out from all the chemical elements because of the remarkable diversity of its compounds.

Organic substances play an enormously important role in life. It is these substances that make up plant and animal organisms; they are constituents of our food (bread, meat, butter, and vegetables); they provide materials for the manufacture of clothing (fabrics, leather, etc.), form various types of fuel, and are used by us as drugs, dyes, and so on.

Organic substances have certain distinctive features. They are comparatively readily decomposed by heating, are mostly combustible, and their chemical reactions proceed more slowly as a rule than those of inorganic substances.

There is, however, no sharp dividing line between organic and inorganic substances. The carbon oxides, carbonic acid and its salts ought to be classified as organic substances because they contain carbon, but their properties are such that they are more closely related to inorganic substances.

Apart from carbon, the elements that organic substances contain most frequently are hydrogen, oxygen, and nitrogen; somewhat less frequent constituents are sulphur, phosphorus, the halogens, and certain metals.

Organic substances are easy to identify: when heated, they become charred or else burn with the formation of carbon dioxide.

The term “organic substances” arose early in the XIX^th century, when many scientists believed that these substances were only produced by living organisms through the operation of a “vital force” and could not be produced artificially from inorganic substances. The doctrine concerning a “vital force”, known as vitalism, was unscientific, since it was founded on the belief in some supernatural power. By its contention that organic substances could not be created from inorganic matter, vitalism hampered scientific progress. Nevertheless, it could not, of course, halt the process of the accumulation of knowledge about nature.

In 1828 the German chemist F. Wöhler succeeded in preparing an organic substance (urea) from an inorganic for the first time. In 1854 the French chemist M. Berthelot prepared fats artificially. In 1861 the Russian scientist A.M. Butlerov carried out the first synthesis of a saccharoid substance. Syntheses of substances formerly produced by living organisms only began to follow one another in rapid succession.

Today chemists have not only synthesized many of the organic substances occurring in nature, but have prepared substances that do not occur in nature, such as plastics, various types of rubber, dyes, explosives, and medicines. Chemistry is now on the road to the artificial preparation of proteins, the most complicated substances of all, and beyond doubt this will be accomplished.

Tasks on the text

1. Memorize the following words and word combinations.

substance [`sAbst(q)ns] – вещество carbon [`kRb(q)n] – углерод to be concerned with – изучать, иметь дело с to exceed [Ik`sJd] – превышать to single out – выделять constituent [kqn`stItjuqnt] – компонент, составная часть fabric – ткань leather[`leDq] – кожа drugs – лекарства dyes [daIz] – красители distinctive [dI`stInktIV] – отличительный, характерный

combustible [kqm`bAstqb(q)l] – горючий, воспламеняемый carbonic acid [kR`bOnIk `xsId] – угольная кислота halogen [`hxlqGqn] – галоген to char [CR] – обжигать, обугливать(ся) to hamper – препятствовать to halt [hO:lt]– остановить urea [juq`rJq] – мочевина explosives [Ik`splqVsIvz] – взрывчатые вещества saccharoid [`sxkq,rOId] – сахароид, сахаровидный to accomplish [q`kAmplIS] – совершать, выполнять; доводить до конца