Find definition for each of the terms given.

a) adhesive; b) acetylsalicylic acid, aspirin; c) arsphenamine, salvarsan; d) dichlorodiphenyltrichloroethane; e) Perkin's mauve, mauveine;

f) atoxyl; g) cyanate; h) fat; i) alkali, -lis/ -lies;

j) plastic; k) urea; l) quinine; m) soap.

1. А soluble base or a solution of a base.

2. A cleaning or emulsifying agent made by reacting animal or vegetable fats or oils with potassium (калий) or sodium hydroxide.

3. Any of a class of naturally occurring soft greasy (жирный) solids that are esters of glycerol (глицерин) and certain fatty acids. They are present in some plants and in the adipose tissue (жировая ткань) of animals, forming a reserve energy source, and are used in making soap and paint and in the food industry.

4. A reddish-purple aniline dye.

5. Any salt or ester of cyanic acid (циановая кислота), containing the ion -OCN or the group –OCN.

6. A bitter crystalline alkaloid extracted from cinchona bark (хинная кора, кора хинного дерева), the salts of which are used as a tonic (тонизирующий), antipyretic (жаропонижающий), analgesic (анальгетик), etc., and in malaria therapy. Formula: C₂₀H₂₄N₂O₂.

7. A substance used for sticking objects together, such as glue (клей), cement, or paste.

8. Any one of a large number of synthetic usually organic materials that have a polymeric structure and can be moulded when soft and then set, esp. such a material in a finished state containing plasticizer (смягчитель, пластификатор), stabilizer, filler (за/наполнитель), pigments, etc. They are classified as thermosetting (such as Bakelite) or thermoplastic (such as PVC) and are used in the manufacture of many articles and in coatings, artificial fibres, etc.

9. A white crystalline compound widely used in the form of tablets to relieve (облегчать, ослаблять) pain and fever, to reduce inflammation, and to prevent strokes (приступ, инсульт). Formula: CH₃COOC₆H₄COOH.

10. A drug containing arsenic, formerly used in the treatment of syphilis and related infections.

11. A colourless odourless substance used as an insecticide (инсектицид, средство от насекомых). It is toxic to animals and is known to accumulate in the tissues. It is now banned in the UK.

12. The name of a drug consisting of p -aminophenylarsenic acid. This organoarsenic compound was used in the late 19th and early 20th centuries, but is now considered dangerously toxic.

13. A white water-soluble crystalline compound with a saline taste and often an odour of ammonia, produced by protein metabolism and excreted in urine. A synthetic form is used as a fertilizer, animal feed, and in the manufacture of synthetic resins. Formula: CO(NH₂)2 Also called: carbamide.

TEXT 3. BUTLEROV’S THEORY OF THE CHEMICAL STRUCTURE OF ORGANIC COMPOUNDS. PART I

A certain number of organic substances were known to man and used by him in ancient times (acetic acid, ethyl alcohol, oils, starch, dyes, and some others). But the rapid advance of organic chemistry as a science began only in the XIXcentury, when the requirements of developing production caused many new organic substances to be discovered and investigated.

In the course of these discoveries there emerged facts that could not be interpreted in terms of the chemical theories current at the time.

In the fifties of the XIX century the valence of the chemical elements had become a scientific concept. The German chemist August Kekule established the quadrivalence of carbon. But in many organic compounds the valence of elements appeared to be invalid. Indeed, try to determine the valence of carbon, say, in ethane C₂H₆ or in propane C₃H₈ by the method familiar to you from inorganic chemistry. You will obtain a strange result: the carbon in ethane will appear to be trivalent (6/2), while in propane it willeven seem to have a fractional valence (8/3).

Other problems arose too: why does the composition of the molecules in the hydrocarbon series increase every time precisely by one carbon atom and two hydrogen atoms; what is the reason for the diversity of organic compounds; why is it carbon and not some other element that forms so many compounds. Other facts also defied explanation, such as the existence of substances of absolutely identical composition and, hence, having the same molecular formula, but exhibiting markedly different properties.

All these and many other facts were explained by the theory advanced in the sixties of the XIX century by the great Russian chemist Alexander Butlerov.

The analysis of a vast amount of scientific data led Butlerov to the conclusion that the explanation of the baffling facts that had accumulated should be sought in the structure of molecules, made up of atoms. Contrary to the views of other scientists, who attached no significance to the structure of molecules and even regarded it as something that science could not probe, Butlerov maintained that chemical structure could fully be established and that only an understanding of the inner structure of molecules could resolve the deadlock inscience and arm it with a theory that would enable it to make further successful progress.

Butlerov’s teachings about the structure of molecules came to be known as the theory of chemical structure.

The main points of the theory of chemical structure may be formulated as follows:

1. The arrangement of atoms in molecules is not a random one; they are linked to one another in a definite order, according to their valence.

2. The properties of substances depend not only on which atoms and in what amounts make up the molecules, but on the order in which these atoms are connected.

 

Tasks on the text

Memorize the following words and word combinations.

1. acetic acid[q`sJtIk xsId] – уксусная кислота 2. ethyl alcohol[`eTIl `xlkqhql] – этиловый спирт 3. starch[stRtS] – крахмал 4. to cause [kO:z] – послужить причиной, поводом (для чего-л.) 5. in terms of– в терминах, в переводе на, говоря языком; исходя из 6. requirement[rI`kwaIqmqnt] – требование, необходимое условие 7. valence [`veIlqns] (valance, valency) – валентность 8. invalid – недействительный, необоснованный 9. to obtain – получать 10. hydrocarbon [,haIdrqu`kRb(q)n] – углеводород

11. defy[dI`faI]explanation – не поддаются объяснению 12. hence – следовательно, поэтому 13. to accumulate[q`kju:mju,leIt] – накапливать, собирать 14. to attach to – прикреплять, привязывать; придавать значение 15. to probe[prqub] – прощупывать, исследовать 16. to maintain[meIn`teIn] – поддерживать, сохранять 17. inner structure[`strAktSq] – внутренняя структура 18. resolve[rI`zPlv]the deadlock – выйти из тупика 19. arrangement[q`reIGment] – расположение 20. random – случайный, произвольный

Practise the pronunciation of the words. Revise their meanings.

Emerge [I`mq:G], interpret [In`tq:prIt], theories [`TIqrIz], current [`kAr(q)nt], quadrivalence [,kwOdrI`veIlqns], determine [dI`tq:mIn], molecule [`mPlI,kjHl], ethane[`JTeIn], propane[`prqupeIn],trivalent [,traI`veIlqnt], series [`sIqrJz], precisely [prI`saIslI], formula [`fLmjqlq], exhibit [Ig`zIbIt], conclusion [kqn`klHZ(q)n],significance[sIg`nIfIkqns],further[`fq:Dq],successful [sqk`sesful].

Read, translate and define what parts of speech the words, their derivatives and related words belong to. Consult the dictionary, write out the meanings that are new for you and memorize them.

Structure – structural – structureless; require – required – requirement; science – scientific – scientist; valid – invalid – validation – validity – validness; determine – determined – determinate – determinative; fraction – fractional – fracture – fractural; molecule – molecular; analys(z)ation – analyse (analyze) – analyses – analysis; advance – advanced – advancement; datum – data; define – definite – definition.

Translate the following words and word combinations into Russian.

Rapid advance, in the course of, current at that time, to establish, to appear to be, indeed, hydrocarbon series, diversity, existence, to exhibit markedly different properties; a vast amount, to lead to the conclusion, baffling facts, contrary to the views, to attach no significance, to arm, to enable, to make progress, as follows, to one another, in a definite order, according to.

Look through the text and find the word combination “a fractional valence” and explain its meaning.