Answer the questions. An experiment in the laboratory

EXERCISES

Vocabulary

AN EXPERIMENT IN THE LABORATORY

Describe the functions of each piece of equipment.

A laboratory method for the preparation of hydrogen chloride solution. Hydrogen chloride is most conveniently prepared in the laboratory by combining concentrated sulphuric acid and sodium chloride and then heating the mixture. We place the sodium chloride in the flask and the sulphuric acid is slowly added through the funnel. The flask is heated with a small flame. The reaction of the sulphuric acid and the sodium chloride yields sodium hydrosulphate and hydrogen chloride as represented by the equation

NaCl + H₂S0₄ → NaHS0₄ + HC1. The hydrogen chloride gas is collected in the first bottle as it displaces the air. When the bottle is filled, the gas will continue on to pour into the second bottle where it dissolves in water and forms hydrochloric acid.

A laboratory method of preparing hydrogen. The usual laboratory method of preparing hydrogen is to replace the hydrogen in an acid by a metal. For example, if a metallic zinc is mixed with dilute hydrochloric acid, the zinc replaces the hydrogen in the hydrochloric acid (hydrogen chloride). This action produces zinc chloride and hydrogen as shown in the following equation:

Zn + H₂S0₄ → ZnS0₄ + H₃

A small amount of granulated zinc is placed in the bottle. Dilute hydrochloric acid is poured into the bottle through the tube. The hydrogen which is freed passes through delivery tube to the collecting bottle.

sulphuric acid - сірчана кислота

hydrochloric acid - соляная кислота

collecting bottle - склянка-колектор

pour - лити, доливати

combine - поєднувати

preparation - приготування

conveniently - зазвичай

represent - представляти

flame – полум’я

solution - розчинення

mix – змішувати

1. How is hydrogen chloride prepared in a laboratory?

2. Is the mixture cooled while preparing hydrogen chloride?

3. What does the reaction of the sulphuric acid and the sodium chloride yield?

4. Where is hydrogen chloride collected?

5. Is oxygen evolved in this reaction?

6. What does hydrogen chloride gas form when it is dissolved in water?

7. What is the usual laboratory method of preparing hydrogen?

8. How is hydrochloric acid prepared?

2. Give Ukrainian equivalents:

1. a small flame а. як показано

2. the usual method b. невелика кількість

3. as shown c. через трубку

4. a small amount d. звичайний метод

5. through the tube e. слабке полум’я

3. Translate the sentences:

1. We place the sodium chloride in the flask and add sulphuric acid through the funnel. 2. The hydrogen chloride gas displaces air from the bottle. 3. A metal replaces hydrogen in an acid. 4. If we mix metallic zinc with dilute hydrochloric acid, zinc replaces the hydrogen in the hydrogen chloride. 5. We know that thermonuclear fusion reactions can yield high temperatures. 6. Research on this matter may yield information useful to the construction of such a device. 7. The discovery of X-rays has yielded certain branches of medicine, radiology, radiotherapy and crystallography. 8. The experiment yielded no results. 9. The yield in this branch of industry contributed much to national economy. 10. The word laboratory is used to denote any room or building devoted to experimental investigation in techniques and sciences for purpose of advancing man's knowledge of special applications of natural laws.

4. Make the questions to the sentences:

1. Не usually carries out the experiments in the laboratory of inorganic chemistry. 2. She studied at school last year. 3. He will study English at the Institute. 4. I get up at 7 o'clock. It takes me 45 minutes to get to the Institute. 5. I lived far from the Institute last year. 6. He will not go to the theatre tomorrow. 7. They went to the theatre yesterday. 8. We go to the cinema on Sundays. 9. They study in the reading-hall every day. 10. We shall finish the experiment tomorrow. 11. The students passed all the exams in January.

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