Text. Laboratory

All the laboratories of inorganic chemistry are almost alike. These are large rooms where both students and research- workers carry out their experimental work. Modern laboratories of inorganic as well as organic and analytical chemistry are provided with gas and running water. Every laboratory is to be provided with a ventilating hood for the escape of both harmful and unpleasant vapours and odours. Every laboratory has to be lit up very well.

There are many laboratory benches with a great number of drawers in every laboratory. Different apparatus devices as well as materials are to be kept in them. Besides we can see many shelves and cases for containers with chemicals.

On every laboratory bench one can see test-tubes, flasks, beakers, funnels, evaporating dishes, weighing bottles. AH this glassware should be kept in good order.

Various burners serve for producing flames. Bunsen burner is to be mentioned among them.

Different crucibles are to be employed when heating of solution and igniting of materials are to be carried out. Crucibles are usually made of quartz, porcelain and iron. In addition to these crucibles, there are platinum crucibles in some laboratories, but they are used very seldom.

Every laboratory should be equipped with different kinds of apparatus. Everything in the laboratory is to have its definite place.

Ex. 7 Дайте відповіді на питання

1. What do we call a laboratory? 2. In what laboratories can the students carry out their experiments? 3. What is every laboratory provided with? 4. Why is every laboratory provided with a ventilating hood? 5. What can you see on the shelves?

6. What glassware is there on every laboratory bench?

7. What are burners used for? 8. What are crucibles used for? 9. What are crucibles made of? 10. What is it necessary to do if we want to obtain hydrogen chloride? {describe the experiment) 11. How can nitric acid be prepared in the laboratory?

Ex. 8 Дайте відповіді на питання

Model: May I come into the laboratory? Yes, you may. No, you can't.

1. May he look through these documents? 2. May I take this test-tube? 3. May we use this glassware? 4. May she heat this substance?

Ex. 9 Знайдіть синоніми.

alike, nearly, different, similar, almost, various, employ, obtain, use, get.

Ex. 10 знайдіть антоніми.

large, inorganic, cool, small, organic, harmful, pleasant, often, useful, unpleasant, seldom, warm, heavy, tasteful, in­definite, light, testless, definite.

Ex. 11 Перекладіть речення.

1. The laboratory of general chemistry has many benches with a number of drawers. 2. A first-year student has to carry out a number of experiments in the laboratory of general chemistry. 3. This term the students have carried out a number of experiments. 4. These substances have very low solubility. 5. They have to find out the solubility of this substance. 6. They have found the solubility of this substance and now can investigate its properties better. 7. This metal has found wide application both in industry and in agriculture. 8. They have to raise the temperature greatly as the mixture doesn't boil. 9. Hydrogen peroxide has been heated.

10. Hydrogen peroxide has a lower vapour pressure than water.

11. The evaporation has to be carried out in the waterbath.

12. This crucible has been used for heating some solutions. 13.This solution has an unpleasant odour, he has to open the window. 14. A rombic sulphur has to be kept at a temperature of 96°C. 15. It is necessary to purify water, you will have to pass it through porous paper. 16. It has to be noted that chlorine dioxide reacts with water and yields a mixture of chlorous and chloric acid. 17. It has been already noted that hydrogen is found in the free state only in minute quantities.

Ex. 12 Перекладіть речення.

1. This substance is colourless and odourless. 2. Liquids which are not appreciably soluble in each other are called immiscible liquids. 3. Many new research institutes are being built in our country. 4. They are discussing a very important problem dealing with the development of new branches of chemistry. 5. The volume of an object increases when it is heated. 6. There is a large new laboratory in our Institute, 7. This experiment is to be carried out again, the results are wrong. 8. The meeting of our Chemical Society is to take place tomorrow at 5 o'clock. 9. He is to graduate from the Chemico-Technological Institute in 1988. 10. This solution was to be heated in a porcelain crucible. 11. The solution was heated and evaporated. 12. The glassware is to be washed very thorough­ly when the experiment is over

Ex. 13 Завершіть речення як у зразку.

Model: This year he must work very hard, but a year ago

he didn't have to.

1. Now I must help her but last year I ... 2. This term the students must attend the lectures in the evening but last term they ... 3. We must carry out a number of experiments but a year ago we . .

Ex. 14 Знайдіть речення в яких дієслово"to be" є модальним

1. The laboratory was lit up very well. 2. This substance is to be heated to a high temperature. 3. In this experiment we were to find out all the properties of this substance. 4. This example was referred to by our teacher. 5. Hot water is to be poured in a flask. 6. If dry chlorine gas is passed into the liquid trichloride in a cooled container, the pentachloride is formed. 7. Silver is not attacked by oxygen under ordinary conditions. 8. The use of this gas is to be omitted as it is very harmful. 9. If the boiling point of the solution is to be established, you should carry out this experiment. 10. Many ores which are to be refined often contain considerable quanti­ties of impurities. 11. He is working at a very important experiment, it is to help our researchers to finish their work. 12. The vapor pressure of this unstable phase is greater than that of the stable phase at the same temperature

LESSON 6

Grammar; I. Modal Verbs (continuation),

2. The use of since.

Text: The Measurements in Chemistry

Ex. 1 Прочитайте речення швидко

1. We studied the measurements in chemistry. 2. This is the one type of measurement. 3. The microscope is an instrument for making very small objects look larger. 4. The fundamental unit of the metric system is the metre.

Ex. 2 Вставте"to have to", "to be to", "must"

1. The experiment , . . take place on Monday, I think everything is ready. 2. They . . . examine this sample under a very powerful microscope as it is very small. 3. I am very tired, I ... have a rest. 4. Our meeting . . . take place after our last lecture. 5. You . . . work hard if you want to finish this work. 6. I ... go to the reading-room as I have no books at home. 7. He ... wait for two hours as his train has just left. 8. All the students of our Institute . . . carry out a number of experiments in analytical laboratory.

Ex. 3. Вставте" "can", "could", "to be able to";

1. If you come earlier, I . . . help you. 2. This solution,.,. be evaporated now. 3. Yesterday he ... finish his experiment, I think he ... do it today. 4. As he was very busy he, . . attend the lecture.

Ex. 4 Перекладіть речення.

1. Since we know all the properties of the substance, we can use it in our experiment. 2. Many interesting investigations have been done since the foundation of this research laboratory at our plant. 3. Helium belongs to the same group as argon since it does not combine with other elements. 4. I have not carried out any experiments in the laboratory sinceI graduated from the Institute. 5. We couldn't finish our work since we had no necessary devices. 6. Since the kinetics of the reaction was studied at room temperature, the results were good. 7. This element has been known since the 19th century.

Ex. 5 Перекладіть речення.

I. D. I. Mendeleyev arranged the elements in the order of increasing atomic weights. 2. In order to be used in a chemi­cal laboratory natural water must be purified. 3. The order was announced at the meeting. 4. In order to dissolve this sub­stance one must heat it. 5. The students must put everything in order when they finish their work. 6. In order to study the relationship between microstructural and mechanical prop­erties of the gel, it is very important to use pure stable gels

. Ex. 6 Перекладіть слова

close relationship, exact measurement, quantitative analysis, necessary method, the order of arrangement

Перекладіть текст

.

THE MEASUREMENTS IN CHEMISTRY

In order to understand the quantitative relationships which exist between various kinds of matter, the chemist who is interested in matter and the changes which it undergoes, has to measure the quantities of matter with which he works, that is since mass is the measure of the quantity of matter, he is to measure mass. The measuring device the chemist is to employ in this determination should be the balance.

Since for every chemical change there is always accompanying energy change which the chemist has to take into account, the calorimeter and the thermometer have to be used.

The chemist usually employs graduated cylinders, burettes, pipettes and volumetric flasks for the measurements of volumes of liquids, and the gas burette for the measurement of volumes of gases.

The chemist employs the barometer if he has to measure the pressure.

The analytical chemist and the physical chemist employsuch devices as calorimeters, polarimeters, refractometers and a number of electrical devices.

If the chemist is to examine very small samples of matter, he should use a microscope. The microscope is an instrument which by the combination of lenses permits man to see objects which are too small to be seen with a naked eye. It is an instru­ment which is useful in many sciences and which, although more frequently used in a qualitative way, can also be used quantitatively.