3 Part One. The Predicate

THE ATTRIBUTE
Lesson 25
GRAMATIKA: Определение. Sifatdosh, местоимение, ot, наречие в функции определения.
Section I
Ex. 1. Practise your reading.

The subject of acids and bases led to the development of an interesting series of theories.

Ex. 2. State what parts of speech the following words belong to:acid, acidity, acidic, acidatc, acidification, acidificr

Ex. 3. Define the meanings of the word anyin the following sentences:

1. Are there anytest-tubes on the table? 2. Anystudent of chemistry must know the periodic law. 3. There is not any student in the lab.4. According to Arrhenius, anyhydroxy compound giving hydroxyl ions in water solution was called a base. 5. There are not anyflowers on the windows in our classroom. 6. There are few objections to this theory, if there are any.7. The protonic theory states that a base is anysubstance, molecule, or ion, which accepts a proton. 8. There is little chance, if any.for the reaction to be completed because the temperature is too low.

Ex. 4. Analyse the following sentence:

The subject of acids and bases has long been one o f the most controversial in chemistry.

Text 25 A

Bases
The subject of acids and bases has long been one of the most controversial in chemistry, and led to the development of an interesting series of theories.

In the 17th century, during the infancy of experimental chemistry, acids and bases were defined or described on the basis of their behaviour. Titus, bases were substances that neutralized acids, turned plant dyes blue, had a bitter taste, and had a smooth or slippery feeling to the skin.In the 18th century, following the discovery of oxygen by Joseph Priestley, Lavoisier advanced the idea that oxygen was the acidifying principle of all acids. Thereafter, the experimental approach was largely abandoned and emphasis was placed on the composition of substances instead of the phenomenological properties. The development of the hydrogen theory of acidity and Faraday’s studies of electrolytic conductance in the early 19th century led logically to the watcr-ion theory proposed by

Arrhenius. By this concept a base may be defined as any hydroxy compound which gives hydroxyl ions in water solution. Neutralization then involves the combination of hydroxyl ions with hydrogen formed by the acid, producing water and incidentally a salt. The role of solvent as an ionizing medium for acid-base reactions was emphasized. Although the theory under consideration was very useful and adequate for many reactions in aqueous solution, its many limitations soon became apparent. The theory includes basic substances that are not hydroxy compounds, does not provide for the amphotcrism exhibited by many oxides and salts, and limits the field ofacid-basc reactions to aqueous solutions in spite of many known typical neutralization reactions in non-aqucous solutions.

These objections led to more or less conflicting theories: the protonic theory advanced by Bronstcd and Lowry in 1923 and the older solvent system advanced by Franklin in 1905 and later extended. In terms of the then popular protonic concept, a base is any substance, molecule, or ion, which accepts a proton.

Words and Word-Combinations to Be Memorized

acidify, acidity, adequate, amphoteric, amphotcrism, conductance under consideration, dye, electrolyte, extend, feel, of importance, incident, incidentally, instead of, of interest, medium, objection, plant, provide, in question, role, smooth, solvent, under study, in spite of, typical

Ex. 5. Give the Uzbek equivalents for the following:

lead to, an interesting theory, during the infancy, define, thus, neutralize an acid, a plant dye, a smooth feeling, advance an idea, there after, an experimental approach, place emphasis, instead of, electrolytic conductance, propose a concept, a hydroxy compound, produce a salt, incidentally, although, an adequate theory, become apparent, exhibit amphotcrism, in spite of

Ex. 6. Give the English equivalents for the following:

chegara, suvli eritma, proton nazariyasiga olib keladigan bo'lsa ham, ushbu nazariya nuqtai nazaridan tizimni kengaytirish, har qanday protonni qabul qilish, kislorod kashf qilingandan so'ng, asosan moddalar tarkibi, kislota nazariyasi, 19-asr boshida, ushbu nazariyaga ko'ra, hal qiluvchi, ionlashtiruvchi vositaning roli, ko'rib chiqilayotgan g'oya xatti-harakatlar asosida tavsiflanadi

Ex. 7. Fill in the blanks with articles where necessary.

1. In terms o f ... protonic concept,... base is ... substance which accepts ... proton. 2. The subject of... acids and bases is one o f ... most interesting in ... chemistry. 3. I n ... 18th century Lavoisier advanced... idea that oxygen was the acidifying principle of all acids. 4. Following... discovery of oxygen ... emphasis was placed o n ... composition o f ... substances. 5. Many typical neutralization reactions occur in ... nonaqucous solutions.

Ex. 8. Give the synonyms for the following:

lead to, a series of, following (the discovery), advance an idea, thereafter, a concept, producc, exhibit

Ex. 9. Give the antonyms for the following:

long, the most popular, before, in the early 19th century, useful, extend, older

Ex. 10. Translate the sentences into Uzbek.

1 . One of the most controversial problems in chemistry was that of acids and bases. 2. The development o f the hydrogen theory of acidity and Faraday’s studies of electrolytic conductance led to the water-ion theory.3. The role of solvent as an ioinizing medium for acid-base reactions was pointed out. 4. The property in question was very useful for many reactions in aqueous solutions. 5. The theory was important, but its many limitations soon became apparent. 6. Analytical chemistry detects, purifies, and answers the questions “What?” and “How much?”. 7. A liquid solution, the ocean, covers three-fourths of the earth’s surfacc. 8. Any explosive substance must be handled with care. 9. Increase in pressure lessens the volume of a gas; increase in temperature increases the volume. 10. Calcium and silicon carbides are representatives of the direct union of carbon with metals and non-metals. 11. The word “chemical purity” is connected with the thought of absencc of constituents other than the substance in question. 12. The atomic theory was John Dalton's great contribution to the world’s knowledge.13. The most important chemical property of oxygen is its acidity. 14. Pure sulphuric acid is a colourlcss, oily liquid about twice as heavy as water. 15. Atoms of the same element, with the same nuclear charge, but with different weights, are called isotopes of that clement. 16. Science must always answer at least two questions — “What?” and “Why?”. 17. No branch of science is broader in its scope than chemistry. 18. In a strict sense, no substance is entirely insoluble. 19. The then president of the Russian Academy of Sciences was М. V. Lomonosov. 20. One solution is said to be more concentrated or more dilute than another. 21. Water is the most widely distributed compound. 22. The properties of plant dyes is the problem under consideration. 23. Another factor of great importance is the proper selection of reacting substances. 24. Let us consider the second condition. 25. Every year a great number of new discoveries are made in chemistry. 26. We consider it a step forward to develop the new technology of obtaning this material. 27. Both ways are possible. 28. The hypothesis under study may prove to be right. 29. It is not always possible to predict the far-off results. 30. The data below must be taken into account in this consideration.

Ex. 11. Translate the sentences into English without using a dictionary.

1. Ko'rib chiqilayotgan nazariya juda qarama-qarshi. 2. 17-asrda kislotalar va asoslar faqat ularning xatti-harakatlari asosida tasvirlangan. 3. Asoslar kislotalarni neytrallashtiradigan va bir qator boshqa xarakterli xususiyatlarga ega bo'lgan moddalar ekanligiga ishonilgan. 4. Kislorod kashf qilingandan so'ng, moddalar tarkibiga katta e'tibor berildi. 5. Vodorodning kislotalilik nazariyasining rivojlanishi va elektrolit o'tkazuvchanligini o'rganish Arrenius nazariyasini yaratishga olib keldi. 6. Erituvchining roli kislota asosli reaktsiyalar uchun juda muhimdir.

Ex. 12. Answer the following questions:

1. What substances were regarded as bases in the 17th century? 2. What important discoveries led to the water-ion theory? 3. What is a base according to Arrhenius? 4. What are die objections to the Arrhenius theory?5. What theory was proposed in 1923?