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2Нг + Oj —» 2НгО.
A mixture of hydrogen and oxygen can be kept for years but we can observe no appreciable reaction taking place.
That is why it is not unusual to hear chcmists speaking about the factors that determine the rate of a reaction. These are manifold. The rate depends not only upon the composition of the reacting substances, but also upon their physical form, the intimacy of their mixture, the temperature and pressure, the concentrations of the reactants, spccial physical circumstances such as irradiation with visible light, ultraviolet light, X-rays, neutrons, or other waves or particles, and the presence of other substances that affect the reaction but arc not changed by it.
W ords and W ord-Com binations to Be M emorized
affect, appreciable, collidc, collision, concentration, fcnic, a few, on the other hand, influence, ion, ionic, neutralization, in order for, permit, proceed, reduction, take place, that is why, transfer, ultraviolet, unusual, visible, wave, X-ray
Ex. S. Give the Russian equivalents for the following:
require time for, oxidation state, be extremely fast, nearly every time, collide with, form the precipitate, oxidation-rcduction reactions, in order for a reaction to take place, transfer electrons, observe a reaction, the intimacy of mixture, irradiation with light, ultraviolet light, affect the reaction, hydronium ion
Ex. 6. Give the English equivalents for the following:
влиять на скорость реакции, без изменения окислительного со стояния, нейтрализация кислоты основанием, смешивать растворы, число столкновений, так что, такой как, хлорид серебра, несколько секунд, с другой стороны, сталкиваться для того чтобы, при комнат ной температуре, смесь водорода и кислорода, наблюдать, вот поче му, зависеть от, видимый свет, рентгеновские лучи
Ex. 7. Fill in the blanks with prepositions where necessary.
1. One can give ...
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an example
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... a reaction which may require ...
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a
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few seconds ...
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its completion. 2 ....
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the other hand, oxidation-rcduction
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reactions arc sometimes very slow. 3. An example ...
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a reaction that is
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extremely slow
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... room temperature is that
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... hydrogen and oxygen. 4. It
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is quite usual to hear chemists speaking ...
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the factors that influence ...
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the rate ... a'reaction.
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5. The reaction rate depends
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... many factors.
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Sometimes the presence ... other substances affects ... the reaction.
Every reaction takes different time ... its completion.
Ex. 8. Translate the scntcnccs into Russian, paying attention to different functions of the word order.
1. St. Petersburg University was awarded the Order of Lenin in 1944 and the Order of the Red Banner of Labour in 1969.2. In arranging his ideas for the book Principles o f Chemistry Mendeleyev felt the need to bring to inorganic chcmistry the same degree of order that was being achieved in organic chcmistry. 3. We were ordered to start the work immediately. 4. In order for a reaction to take place, the collision between the ions must result in the transfer of electrons from one ion to another. 5. In order that the reaction might occur, the reactants should be heated. 6. We must measure all the parameters in order to summarize them in a table. 7. Crystalline compounds have their atoms arranged in a certain order.
Ex. 9. Translate the sentences into Russian.
The door was open and we could hear Prof. N giving his lecture.
Coming up to him for the second time I found his experiment finished.
We saw the powdcr darkcning when it was exposed to light. 4. We shall have our papers checked and then we shall be permitted to do the experimental part. 5. We all heard her saying so.Ss wc may treat the
clcctrons in the shared clcctron pair as belonging to both atoms. 7. Wc usually think of a substancc as being in a certain physical state. 8. Solutions arc often thought of as being liquids. 9. They watched the sugar crystals disappearing in water. 10. Lavoisier considered oxygen as being a constituent of all acids. 11. After Dalton wc find the atomic theory developed rather than rejected. 12. The inertness of the noble gases is accounted for by the fact that they have all their shells completely filled. 13. Wc had our laboratory equipped by the beginning of a new academic year. 14. Wc saw the solution turning blue as the reaction proceeded.
They observed the temperature slowly rising. Ex. 10. Translate the sentcnccs into English.
Все химические реакции происходят с различной скоростью.
Скорость реакции зависит от состава реагирующих веществ и ус ловий реакции. 3. Существует множество факторов, которые оказы вают влияние на реакцию. 4. Среди них прежде всего следует на звать температуру, концентрацию, наличие катализаторов и другие.
С точки зрения молекулярной кинетики легко объяснить влияние температуры. 6. Иногда скорость реакции в значительной степени зависит от присутствия катализатора.
Ex. 11. Answer the following questions:
What reactions procccd fast? 2. What reactions arc usually slow?
In what way is silver chloride formed? 4. What example of oxidation-rcduction reaction can you give? 5. What factors influence the reaction rate? 6. In what way can one classify these factors?
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