английский за проф направлением. Укладач Триполець В.І. Рецензенти
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particle – частка; to stipulate – обумовлювати; digestion – травлення; slippery – слизький; property – властивість; to vanish – зникати.
CHEMICAL COMPOUNDS There are three big classes of chemical compounds: acids, bases and salts. What are acids? In Latin, the word meaning "sharp" is acidits. Think of the acute mouth sensation that the mention of rhubarb, lemon juice and vinegar produces and you will understand the derivation of the word. These substances are "sharp" or sour. Acetic acid is present in vinegar; ants' stings and stinging nettles contain formic acid; citric acid is one of the substances found in citrus fruits such as lemon; grape juice includes tartaric acid; sour milk presents us lactic acid; green apples are rich with malic acid; sour taste of rhubarb and spinach is stipulated by oxalic acid. Finally, in our stomach, hydrochloric acid provides digestion. In the laboratory you can find the following acids: hydrochloric acid, nitric acid, sulphuric acid, phosphorous acid, carbonic acid. Some acids, such as citric, boric and tartaric, are solids, butyric acid is a liquid. Many acids arc water solutions of gases. In most cases, however, the significant acid properties do not become evident until the substance has been dissolved. Chemically, the action of acids is due to the presence of hydrogen ions, H+, that determines its chemical properties. An acid is a substance whose water solution yields hydrogen ions. Acids turn litmus from blue to red and conduct electricity, What are bases? Bases are substances whose properties are chemically opposed to those of acids. While acids are sour, bases are usually bitter, if you rub some sodium hydroxide solution between your fingers, you will note that it feels slippery. All solutions of strong bases feel the same way because they react with the oil of your skin to actually make soap. All bases contain the hydroxyl radical, OH-, determining chemical properties of bases. Thus, a base is any substance whose water solution yields hydroxyl ions. As chemically opposed to acids, bases have opposite properties. To summarize, bases often taste bitter, feel slippery, turn red litmus blue, turn colorless phenolphtalein red, contain one or more of the hydroxyl groups, neutralize acids and finally conduct an electric current in water solutions. Among the most important are sodium hydroxide, potassium hydroxide and so on. Neutralization is the action between an acid and a base to form a salt and water. The hydrogen ion (H+) of acids combines with the hydroxyl ion (OH ) of the base to form water. These ions are charged particles that make all special properties of acid and base vanish. The metal of the base is now free to join with the nonmetal, or radical of the acid to form salt. Thus, a salt is the product other then water, obtained by neutralizing an acid with a base.
- What are you doing in the laboratory now? What are you studying/investigating? - Why are you studying it? - What is new for you in your investigation? - What are the results you are waiting for? - How can the results of your investigation be used in industry/ pharmacology (e.g. what is the use of your analyses?)? - Do you want to continue studying chemistry/pharmacology? - How can the information you study at the University be useful for you? - When you graduate from the University, what will your job be? Imagine your ordinary day at work and tell about it. - Can you synthesize a drug? Which one? If no, what prevents you from doing it? - What do you think of people preparing drugs at home by themselves? - How long should you study to be able to prepare drugs? What sciences should you know and what skills must you possess to be able to work as a pharmacist? Explain your idea.
Pharmacist: Hello. Any problems? What do you need? Customer: Well, 1 feel very bad. Can you give me something for it? Ph.: What do you mean by "bad"? C.: Actually, I've got temperature. Ph.: Fever? C.: Yes, you call it so. I've got stomach ache as well. Ph.: Have you seen a doctor? C.: No, I really don't see any need init. Give me something. Ph.: It is prohibited to give drugs without a prescription. You may be ill with dysentery; it may be influenza, poisoning or even some unknown virus. 27. D. I. Mendeleyev. Periodic Table of the Chemical Element. Д. І. Менделєєв. Періодична таблиця хімічних елементів. I. Vocabulary 1. Learn the new topical vocabulary similarity — схожість; to predict — передбачати; confidence — впевненість; to arrange — розмістити; to enable — робити можливим; inventor — винахідник; density of gases — густина газу; predict — передбачувати; liquefaction of gases — зрідження газу; expansion — розширення; ether — ефір; to perpetuate—увічнити; is regarded — вважається; regular — постійний; efficiency — продуктивність; repetition — повторення; to such an extent — до такого рівня. 2. Study the table. Check the meaning of unknown words in the dictionary.
3. Learn the word definitions. Vacant, adj. — 1. empty, not occupied by anyone: a vacant room e.g. in a hotel — 1. 2. looking as if you do not understand or are not paying attention: a vacant expression/look/smile Confidence,n — 1. expecting smth to be kept in secret or faith 2. secrete.g. to exchange secrets 3. the belief that someone or something is good and that you can trust them: e.g.to have/lose, restore confidence in. Arrange,vt, vi — 1. put in ordere.g. to arrange flowers; make plans in advancee.g. to arrange to meet smb 2. came to an agreement 3. adapt (a piece of music) II. Reading Read the text and write down all key words. D.I. MENDELEYEV Dmitry Mendeleyev was a Russian chemist and an inventor. He was also the father of Periodic Table of Elements. Mendeleyev was born on February 8, 1834 in Verkhnie Aremzyani village, near Tobolsk (Russia). At the age of fourteen, after the death of his father, Mendeleyev attended Tobolsk Gymnasium. He enrolled (1850) in the Faculty of Physics and Mathematics of the Main Pedagogical Institute in Saint Petersburg, from which he graduated with a brilliant record in 1855. He taught (1855—56) at the Odessa lyceum, where he continued work on the relationships between the crystal forms and the chemical composition of substances.  Between 1859 and 1861 he worked on the density of gases in Paris, and the workings of the spectroscope with Gustav Robert Kirchhoff in Heidelberg. In 1860, Mendeleyev discovered the concept of critical temperature and attended the first International Chemical Congress at Karlsruhe, where Stanis-lao Cannizzaro's views on atomic weights planted the seeds for the concept of the periodic table. In 1863, after returning to Russia, he became Professor of Chemistry at the Saint Petersburg Technological Institute (1864—66) and at the University of Saint Petersburg (1867—90), where he gave a course of lectures in theoretical and practical importance. Because he found no suitable text for his students, he wrote his own — Principles of Chemistry (1868—71). The systematization of ideas required for this book led Mendeleyev to formulate the periodic law in March 1869. The law organized the chemical elements known at the time according to their atomic weights and predicted the existence of more elements. He was sent (1876) by the Russian government to study petroleum production in the United States. Mendeleyev also worked on the liquefaction of gases; the expansion of liquids; a theory of solutions; a theory of the inorganic origin of petroleum; the chemistry of coal; Russian weights and measures; and the universal ether. He helped to found the Russian Chemical Society in 1868. Though Mendeleyev was widely honored by scientific organizations all over Europe including the Copley Medal from the Royal Society of London. In his later years, he worked out and investigated the composition and fields of oil and helped to found the first oil refinery in Russia. He died in St. Petersburg (1907), Russia from influenza. His name will be perpetuated in the discovery of new artificial elements and in our better understanding of the mysteries of nature. Element number 101, the radioactive mendelevium, is named after him. III. Post-reading activities 1. Check how well your partner understands the text D.L Mendeleyev by asking him/her the following questions. Use:I think... I suppose... I know...
10. What did he discover (predict)? 2. Are these statements true or false?
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