2018-02-13
1607
5. Complete the sentences using chemical terms from the list below. Some of them can't be used in the given sentences, while the others can be used several times:
Combustion, rusting, hydrogen, oxygen, nitrogen, ardon, inert, reactive, atmosphere, carbon dioxide, cooling, heating, remove, mixture, substance, isolate.
1.... is a corrosion of iron or steel to form a hydrate iron (III) oxide.
2.... occurs in the air (78%) and is an essential constituent of proteins and nucleic acids in living organisms.
3.... is a chemical reaction in which a... reacts rapidly with... producing heat and light.
4.... is a colorless, odorless gas, soluble in water, ethanol and acetone.
5.... occurs only in the presence of both water and....
6. Reactions of... are often free-radical chain reactions, which can usually be summarized as the oxidation of carbon to form its oxides and the oxidation of... to form water.
7.... is really prepared in the laboratory by the action of dilute acids on metal carbonates.
8. Though... is essential to all forms of life, the huge amount present in the... is not directly available to most organisms.
9.... is the lightest element and most abundant at the universe.
10.... is an electrochemical process in which different parts of iron surface act as electrodes in a cell reaction.
11.Flame is a luminous... of gases undergoing....
12.... is a by-product (супутній продукт) from the manufacture of lime (вапно) and from fermentation process.
6. Match the words, word combinations and chemical terms in A with their synonyms in B:
| A | B |
| 1. stuff | a) inert |
| 2. evidence | b) usual |
| 3. to contaminate | c) precisely |
| 4. to sort out | d) to delete |
| 5. ordinary | e) testimony |
| 6. suddenly | f) to isolate |
| 7. exactly | g) much |
| 8. spontaneously | h) matter |
| 9. plenty | i) combustion |
| 10. gradually | j) impulsively |
| 11. burning | k) to pollute |
| 12. rusting | l) corrosion |
| 13. unreactive | m) unexpectedly |
| 14. to remove | n) amalgam |
| 15. mixture | o) little by little |
7. Translate the following text into English paying attention to the italicized parts of the sentences:
За нормальних умов кисень є газом без кольору та запаху, який складається з двохатомних молекул. Для отримання кисню в лабораторних умовах застосовують декілька методів. Кисень – сильний окислювач і, з’єднуючись з багатьма елементами, утворює оксиди. Реакції утворення оксидів екзотермічні (exothermic), що часто призводить до загоряння елемента, який сполучується з киснем або того, який утворює це сполучення.
Кисень та його сполуки необхідні для підтримання життя. Вони відіграють важливу роль у процесах обміну речовин та дихання.
Озон – один із алотропів (allotrope) кисню. Це блакитний газ, що володіє невеликою розчинністю в воді. За низьких концентрацій він нетоксичний, але в концентраціях, які перевищують 100 мільйонних долів, стає токсичним.
Озон реагує з алкенами (alkene), розщеплюючи (to split) їхні подвійні зв’язки (bond) у процесі, відомому як озоноліз (ozonolysis), та утворюючи органічні сполуки, що називаються озонідами (ozonide).
TEXT 11
REACTIONS OF OXYGEN
Learn the new vocabulary:
| the most widely distributed | найпоширеніший |
| globe | глобус, планета Земля |
| maintenance of life | підтримання життя |
| within a few minutes | протягом декількох хвилин |
| supply of oxygen | подача / запаси кисню |
| oxidation | окислення |
| to be unaffected (by) | не зазнавати впливу |
| to liberate heat | виділяти тепло |
| combustion | горіння |
| to catch fire | загорітися |
| to ignite | запалювати, загорятися |
| kindling point | точка горіння |
| to be radiated (to) | випромінюватися / попадати (в) |
| rate of reaction | швидкість / темп реакції |
1. Read and translate the text:
No other element is more important to life than oxygen. It is not only the most widely distributed element on the surface of the globe, but it is absolutely necessary to the maintenance of life. To be sure, air breathing animals would die within a few minutes if the supply of oxygen in the atmosphere stopped suddenly. After we have learned the methods of oxygen's preparation, let us study its main reactions.
Combining with an element, oxygen forms a product called an oxide. The process is called oxidation. There are only a few elements which are attacked by oxygen. Among the substances which are unaffected by it we should mention inert gases.
Combinations with oxygen often liberate heat and light and this process is known as combustion. There are some elements which do not catch fire unless they are heated. Some substances will ignite even if slightly heated; others have to be heated before taking fire. The temperature at which a substance ignites is called its kindling point. Once these reactions are started, they liberate heat and light. The heat which is liberated maintains the substance at or above the kindling temperature.
The amount of heat which is liberated by very slow oxidation such as rusting of metals and the decay of wood is the same as that which is liberated by rapid combustion, but there is no rise in temperature because the heat is radiated to the surrounding air. The difference between combustion, on the one hand, and corrosion and decay, on the other, is one of the rates of reaction and temperature at which these reactions take place.
2. State which of the following statements are true (T), false (F) or not mentioned (NM) in the text:
1. There are many elements that are more important than oxygen.
2. Oxygen is very reactive.
3. Oxygen is a blue-colored gas.
4. The amount of heat liberated on oxidation doesn't depend on the rate of oxidation.
5. Combinations with oxygen seldom liberate heat.
6. Liquid oxygen boils at -185.5°C.
