Химия Answer the questions просмотров - 346
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
conveniently - зазвичай
represent - представляти
flame – полум’я
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.
Dates Ordinal numbers Cardinal numbers Exercise 5. Write down the following in figures.1. twenty-five million seven hundred thirty-two thousand 2. ten million five hundred sixty-seven thousand five hundred fifty-two 3. two million one hundred fifty thousand one hundred thirty-one 4. one million six hundred eighty-two thousand twelve 5. one point three million 6. sixty-seven thousand and five 7. two hundred thousand ninety-five 8. forty-five... [читать подробенее]
1. Exercise 2. Have a look at the adverbs in bolt. Find them in the UNIT and guess their meaning. Read the quotations and translate them. Exercise 1. Find the Russian equivalent. 1. to indulge in 2. to prefer 3. to introduce 4. to expect 5. to proffer 6. to squeeze 7. to exchange 8. to gain A. расценивать B. выражать C. предлагать D. приобретать E. кричать F. следовать G. избегать H.... [читать подробенее]
Ex. 59. Complete the following sentences about the important moments in history using the Past Continuous form of the verbs in brackets. Ex. 58Read the story and rewrite it in the past tense. Ex.57 Using the Past Continuous tense, fill in the blanks with the correct forms of the verbs shown in brackets. Ex.56 Using the Past Continuous tense, fill in the blanks with the correct forms of the verbs shown in brackets. Then rewrite the following affirmative statements as questions... [читать подробенее]
Ex. 48. Explain the use of the Simple Past in the following sentences. The First TV Soap Opera Ex. 47. Put the verbs in brackets into the Past Simple. The first TV soap opera (a) ……….. (appear) on American television just after the Second World War. Its name (b) ………. (be) Faraway Hill and it (c) ……….. (begin) on the 2nd of October, 1946. A famous Broadway actress, Flora Campbell, (d) ………… (play) Karen St. John, a rich New York woman who (e) ……….... [читать подробенее]
EQUITY In a general sense equity means fairness. In English law, equity means that body of rules originally enforced only by the Court of Chancery. Equity has been described as “a gloss (meaning a supplement) on the common law”, filling in the gaps and making the English legal system more complete. Petitions from persons unable to obtain justice in the common law courts were sent to the King as “fountain of justice”. These petitions were sometimes examined by the King and Council... [читать подробенее]
Task 12. Fill in the blanks. Task 11. Guess the meaning of the international words using in the text. Task 10. Make up the questions. SUBMISSION SEAT 1) something to sitting on, e.g. a chair 2) a place where something is, or is located or based 3) a parliamentary constituency 4) membership in legislative body1) act of accepting the power or authority of another 2) legal theory, opinion presented to a judge or jury 3) the act of presenting something, e.g. a... [читать подробенее]
Task 10. Make up sentences using the following expressions. Judicial branch, according to, the highest tribunal, Chief Justice, to be appointed by, to be approved by, to alter, successful experience, to pass laws, to be authorized, principal duty, to be at stake. 1. What responsibility does the judicial branch have? 2. What kind of court is the judicial power vested in according to the Constitution? 3. Could you describe the Supreme Court of the USA? 4. What do you know about the... [читать подробенее]
Part two Discuss the following before you listen. You will hear an interview with Tim Rice, who wrote the lyrics for Part one The writerJesus Christ Superstar. It was first performed in the 1970s, but hasn’t been performed many times since. Andrew Lloyd Webber composed the music. a) What are some of the main events in the life of Jesus Christ? Who were some of the main characters in his life? b) Why do you think Tim Rice and Andrew Lloyd... [читать подробенее]
Ex. 3. Read and translate the text. The Randolf sisters, Sadie and Esther, live just a block away from each other. Sadie constantly complains that the people in town are cold and unfriendly, while Esther finds them warm and pleasant. Although Sadie can’t see it, the difference is in the way they approach those people. Sadie and her husband have a lovely house. It’s filled with beautiful antique furniture and glassware that is so fragile it could easily be broken by a careless guest... [читать подробенее]
Discussion Ex. 1. Read and translate the text. Ex. 2.Work in pairs. Ex. 1. Answer the questions. Discussion 1. What are the three types of housing mentioned? 2. What is the ratio of houses to flats in Britain? 3. What has happened to home ownership in Britain? 4. What sort of people in the UK are most and least likely to own their houses? 5. Explain the following: sheltered housing, a mortgage, a slum area.1. What differences are there between housing in... [читать подробенее]