Vocabulary

1. superdence – сверхплотная 2. to regard – рассматривать 3. hence – следовательно 4. negligible – незначительный 5. to compare – сравнивать 6. slightly – слегка 7. vit (namely) – а именно 8. choice – выбор

9. to cause – быть причиной 10. stable – постоянный 11. to dilute – растворять 12. to drop - капать 13. to assume - предполагать 14. impact – влияние 15. to burn – жечь, сжигать 16. to purity – очищать 17. to saturate - насыщать 18. to choose – выбирать

II. Выполните упражнения

1. Дайте русские эквиваленты к следующим словам, словосочетаниям и химическим терминам. Где конкретно они используются в тексте, а какие нет?

nouns: 1. condition, 2. current, 3. hydrogen oxide, 4. importance, 5. point of view, 6. quarter, 7. surface, 8. vapour

verbs: 9. burn, 10. cool, 11. cover, 12. heat

adjectives: 13. artificial, 14. dangerous, 15. marked, 16. strict

adverbs: 17. commonly, 18. exactly, 19. in this way

conjunctions: 20. either... or.

2. Подберите к словам из упр. 1 синонимы, данные ниже

1. to warm up к) water

2. usually 1) viewpoint

3. stream m) synthetic

4. steam n) to fire

5. to chill o) rigorous

6. hazardous p) to hide

7. the 4th part of a whole q) significance

h) noted r) the outer part

i) state s) precisely j) thus

3. Найдите антонимы в А и В

А В

1. the commonest a) impossible

2. like b) the most unusual

3. simple c) old

4. usually d) common

5. new e) few

6. single f) eptionally

7. many g) to lose

8. decomposition h) natural

9. to obtain i) unlike

10. possible j) integration

11. easy k) complicated

12. dangerous 1) secure

13. artificial m) lenient

14. strict n) difficult

4. Откройте скобки, выбрав правильную форму предлога, переведите предложения

1. When (heating, having heated) this substance, one should be very careful. 2. (Investigated, having investigated, investigating) all the properties of new water, they could understand the mistery of silvery clouds. 3. The (dissolving, dissolved, having dissolved) materials may be soluble solids, liquids or gases. 4. Water (using, used, having used) in steam boilers, should be free from substances that cause corrosion. 5. (Purified, having purified, purifying) the water from the substance that cause corrosion, we can use it in steam boilders.

5. Поставьте 15 вопросов к тексту

III. Control text

Прочитайте и переведите текст

One of the most striking properties of water is its ability to dissolve many substances, forming aqueous solutions. Solutions are very important kinds of matter – important for industry and for life. The ocean is an aqueous solution that contains thousands of components: ions of the metals and non-metals, complex organic ions, many different organic substances. It was in this solution that the first living organisms developed, and it was from it that they obtained the ions and molecules needed for their growth and life. In the course of time organisms that were evolved could leave this aqueous environment, and move out onto the land and into the air. They achieved this ability by carrying the aqueous solution with them, as tissue fluid, blood plasma, and intracellular fluids containing the necessary supply of ions and molecules.

The properties of solution have been extensively studied, and it has been found that they can be correlated in large part by some simple laws.

Water not only is the most widely used of all solvents, but also, of all liquids, it most nearly approaches being the “universal solvent”. Every substance is probably soluble in water to some extent, although in many cases the solubility is so small that it is almost imperceptible. Thus, a saturated solution of barium sulphate contains less than a quarter of a milligram of solute per litre, and the solubility of silicon dioxide (quartz) – is even smaller than this. Yet, water that is allowed to remain for a long time in a quartz vessel must eventually become saturated with quartz; a saturated solution of this substance is so extremely dilute, however, that many litres of it would have to be evaporated to dryness in order to yield a visible residue. Such substances as barium sulphate, silver chloride, quartz, glass, mercury, and cellulose are usually considered as “unsoluble” in water; but this term, it must be remembered, is merely a relative one, and it would be more accurate to say that their solubility is exceedingly small.

-Передайте основное содержание текста в нескольких предложениях.

-Прочтите предложения и скажите, соответствуют ли они содержанию текста. Если нет, исправьте их.

1. Water can dissolve a great number of substances. 2. Solutions arc important in industry, but not in life. 3. A lot of components are dissolved in the ocean water.

4. The first living organisms developed in water and on the land and then moved into the air. 5. There are no laws common to all the solutions and the properties of each solution are studied separately. 6. Every substance is soluble in water to some

Test 6

1. One of the way to purity water is … it

1. to heat

2. to boil

3. to evaporate

4. to distillate

2. Water is the most … compound

1. usable

2. abundant

3. universal

4. pure

3. The ground water contains a great deal of …

1. impurities

2. mixtures

3. microbes

4. salts

4. When water vapour condences to liquid water, energy …

1. releases

2. will release

3. has released

4. is released

5. Water is a major … of living matter

1. constituent

2. part

3. form

4. substance

6. Water … a very large number of substances

1. evaporates

2. saturates

3. dissolves

4. drops

7. … water is odourless and tasteless

1. ground

2. pure

3. distillated

4. sea

8. Natural water have taste because of the presence of … substances

1. purified

2. distillated

3. evaporated

4. dissolved

9. Several common units of measurement … in terms of the properties of water

1. are used

2. are made

3. are defined

4. are discovered

10. Most of the world’s water is …

1. liquid

2. solid

3. gaseous

4. vapour

Unit 7