Organic chemistry

The chemistry of carbon compounds is called organic chemistry, name originated with early chemists. They noticed the differences between substances derived from living matter (organic compounds) and those derived from minerals (inorganic compounds). Although chemists still speak of organic cot pounds (carbon compounds) and inorganic compounds (all other compounds), these terms are. no longer associated with the origins of the substances.* Living organisms have some inorganic constituents, such as sodium ions, phosphate] ions, calcium ions, carbonate ions, etc., and solid compounds composed of some;! of these constituents. Chemists believe that living organisms gathered some important minerals from water during past geologic eras and deposited them.

The hydrocarbons, which are organic compounds composed of the elements carbon and hydrogen, include some of the smallest molecules and also some of the largest. Their names are identified with certain structures» hence, the j roots of these names are applied even to compounds in which hydrogen atoms have been replaced by other atoms.* For this reason some attention shall be de-1 voted to the various types of molecular structures represented by hydrocarbons and to the names given to these structures.

It is known that the hydrogen atoms in the methane molecule occupy positions at the apexes of a regular tetrahedron with a carbon atom in the centre. This structure is three-dimensional, but it cannot be drawn on the plane of this page except by using perspective. Instead the structure is usually represented as:

H	H
H:C:H or	HCH
H	H

CH₄ - [si: eitj f:]

This representation does not imply, however, that the molecule is flat or Bt any hydrogen atom is opposite any other, for the molecule is tetrahedral.

Methane reacts with chlorine gas to form a series of products. The hydrocarbon name, methane, is retained and modified by prefixes that reveal the ad and number of atoms which are substituted for hydrogen atoms in the methane; molecule. Such compounds are called derivatives of methane.

Ex. I. Find the equivalents:

carbon compounds молекулярная структура

living matter соединения углерода

the origin of the substances откладывать

to deposit живые организмы

molecular structure происхождение веществ

Ex. II a) Find the wrong statement:

1. In our time the terms "organic compounds" and "inorganic compounds" are no longer associated with the origins of the substances.

2. Living organisms gathered some important minerals from water during past geologic eras.

3. The hydrocarbons, which are composed of the elements carbon and | hydrogen, include only the smallest molecules.

4. Methane reacts with chlorine gas to form a series of products.

b) Point out which of the given sentences is the definition of the notion organic chemistry:

1. It is a branch of chemistry which deals with substances derived from minerals and other inorganic compounds.

2. It deals with the structure of atoms and the possibilities of using the atomic energy for peaceful purposes.

3. It is a branch of science which studies different properties of matter.

4. It is a branch of science which deals with carbon and carbon compounds.

Ex. Ш. Insert prepositions wherever necessary:

1. The name "organic chemistry" originated ... early chemists. 2. They noticed the differences ... substances derived... living matter and those derived... minerals. 3. These terms are no longer associated... the origins... the substances. 4. Their names are identified... certain structures. 5. The roots... these names are applied even... compounds... which hydrogen atoms have been replaced... other atoms. 6.... this reason some attention shall be devoted... the various types... molecular structure.

Ex. IV. Translate into English:

1. Эти органические соединения уже изучены. 2. Это химическое вещество только что получено. Следовательно, вы можете начинать он 3. Это вещество было получено уже в XV веке. 4. С этой целью строение этих соединений может быть представлено различными формулами. Состав этого вещества сейчас исследуют. 6. В тот момент, когда растворяли это вещество, вода стала белой. 7. Всегда, когда растворяют это вещество вода становится мутной. 8. Об этих опытах будут много говорить, а этого ученого будут связывать с этими опытами. 9. Производные углеродного соединения изучаются в этой лаборатории. 10. Результатами этого опыта было уделено много внимания еще до того, как была написана эта работа. 11. Эти соединения назвали производными метана. 12. Определению этого вещества было уделено много внимания.

Read this text in 2 minutes without a dictionary, answer the question 'What determines the character of a compound?' and retell the text either in Russian or in English: