English for chemists

THE ADVERBIAL MODIFIER
Lesson 28
ГРАММАТИКА: Обстоятельство. Существительное, наречие, герундий и герундиальный оборот в функции обстоятельства.
Scction I
Ex. 1. Practise your reading.
As long ago as 1833, it was concludcd that clcctrolysis took placc through the transport of cicctricity by mobile charged particlcs.
Ex. 2. State what parts of speech the following words belong to:
clcctron, clcctronic, clcctricity, clcctric, clcctrical, clcctrify, clcctro-chcmistry, clcctrolytc, clcctrolysis, electrolytic, clcctrolyzc, clcctrodc, clcctrostatic
Ex. 3. Define the meanings of the word number in the following sentences:

1. 
   There arc a number of difficulties in the analysis of such systems.
   

2. 
   My telephone number is 2530744. 3. Since the atomic number of hydrogen is 1, a single clcctron makes the atom clcctrically neutral. 4. An ion is regarded to have an clcctrovalcncc equal in number and sign to its chaige. 5. The number of different kinds of molcculcs is enormous. 6. There arc a number of steps which arc common to all metallurgical processes involved in extracting a metal from its ores. 7. An idea able to explain or correlate a number of facts is called a hypothesis. 8. A great number of methods arc now in use preparing silicon.
   

Ex. 4. Analyse the following sentence:

A good deal of succcss in the study of molcculcs in the gas phase prompted chemists to attempt to build up theories of solutions in an analogous way.

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Text 28 A
Interactions in Electrolyte Solutions
In a solution of an cicctrolytc, it is often ncccssary to have a detailed knowledge of the spccics present. New ions or uncharged molcculcs resulting from interactions in the solution may behave quite differently from the constituent ions of the cicctrolytc. Some properties of the solutions will be profoundly affcctcd, and the chcmist, in order to understand these phenomena, will require to know the nature of the spccics present. There arc a number of formidable difficulties in the analysis of such systems and, during the past forty years or so, a great deal of work has been done on the problem. The equilibrium properties of cicctrolytc solutions and the way in which ion-pair and complex formation can be dctcctcd and quantitatively studied arc of primary importance. Although the application of new physical and chcmical methods has produced significant contributions in this field, the information obtained from measurements of a system at equilibrium is to some extent limited, and in studying the phenomenon it is desirable to know the relevant kinetic parameters. Without this understanding, it is sometimes impossible to sketch the actual reaction mechanism by which the system approaches equilibrium. In general, wc may regard the elucidation of the structure of an cicctrolytc solution as a difficult problem which requires as many independent lines of attack as possible.
A good deal of succcss in the study of molcculcs in the gas phase prompted chcmists to attempt to build up theories of solutions in an analogous way. The classical theories regarded the solvent as merely providing spacc in which the solute particles moved and interactions between the ions and the solvent molcculcs were neglected. This

0. 
   assumption can be questioned on the basis of even the most elementary electrostatic considerations.
   

As long ago as 1833, both Faraday and Danicll concluded that electrolysis took placc through the transport of clcctricity by mobile charged particlcs or ions which were discharged at the clcctrodcs. These ions were produced simply by dissolving the cicctrolytc in the solvent and so the conccpt of bond-breaking in the molcculcs of cicctrolytc was first established. It is now realized that the energy required for such a proccss comcs from tlic solvation of the ions. When the ions are introduced into solution, they interact with solvent molcculcs and a considerable heat of solvation may be involved. In order to understand such concepts, it is ncccssary to have a more detailed picture of the structure of the solvent molecules. Although non-aqucous solutions arc of considerable interest, much of the work has been done in aqueous systems and these continue to be of paramount importance.

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Words and Word-Combi nations to Be Memorized
assumption, behave, conclude, considerable, a good deal of, a great deal of, detect, discharge, clcctricity, to some extent, interest, interaction, kinetic, merely, mobile, ncglcct, or so, parameter, primary, realize, result from, transport
Ex. 5. Give the Russian equivalents for the following:
a detailed knowledge, result from interactions, affect profoundly, during forty years or so, the equilibrium properties of solutions, produce a signi­ ficant contribution, the relevant kinetic parameters, ncglcct some parame­ ters, the energy comes from, be of considerable interest
Ex. 6. Give the English equivalents for the following:
взаимодействия ионов и молекул в растворе, влиять на свойства, чтобы понять эти явления, есть ряд трудностей, в течение последних сорока лет, изучать количественно, иметь первостепенное значение, получать информацию, ограничивать до некоторой степени, желатель­ но знать, приближаться к равновесию, посредством переноса, по­ движная заряженная частица, разорвать связь в молекуле, вводить в

раствор, для того чтобы понять, «сводный раствор

Ex. 7. Fill in the blanks with articles where ncccssary.
1. Sometimes it is ncccssary to have ... detailed knowledge about...
composition o f... solution under test. 2. It is desirable to know... relevant kinetic parameters. 3. To understand... structure o f... electrolyte solution is ... difficult problem. 4. It was concluded that... clcctrolysis took place through ... transport o f ... clcctricity by ... mobile charged particles. 5. Much o f ... work has been done in ... aqueous systems.
Ex. 8. Give synonyms for the following:
a number of, a great deal of, do, produce, significant, information, obtain, study, actual, regard, analogous
Ex. 9. Give antonyms for the following:
present, new, uncharged, differently, with, difficult, many, move, more
Ex. 10. Translate the sentences into Russian.
1. It is often ncccssary to understand interactions in clcctrolytc solutions. 2. Some properties of the solutions will be profoundly affected. 3. In studying the properties of a solution, it is desirable to know its composition. 4. Interactions between the ions and the solvent molcculcs were sometimes neglected. 5. On returning, wc shall continue our investigation. 6. Tomorrow you must finish it up. 7. In studying a foreign language, one must leam a lot of foreign words by heart. 8. You arc not allowed to work in the laboratory without learning the safety instruction.

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9. 
   In the proccss of oxidation, the oxygen may be supplied by the air.
   

10. 
    Solids dissolve in liquids only to a limited extent. 11. Pure water conducts the electric current hardly at all. 12. Existence of germanium was predicted by D. 1. Mendeleyev in 1871.13. Crystalline salts generally diflUse rapidly. 14. Due to crowding during formation or to erosion after formation, crystals arc seldom perfect 15. The chcmical properties of ozone are similar to those of oxygen except for its being more activc. 16. Silicon resembles carbon in forming a scries of volatile hydrides. 17. In dealing with crystals, one first encounters ions— atoms or groups of atoms carrying electrical charges. 18. Nearly all mercuric compounds sublime on being heated in the closed vessel. 19. Two elements may combine spontaneously upon being mixed or under special conditions. 20. A catalyst is defined as a substancc that will change the rate of a chcmical reaction without itself being changed. 21. Carbon burns in oxygen on strong heating. 22. In studying chcmistry, it is ncccssary to consider the nature of all kinds of matter. 23. By changing the temperature of the reacting substanccs or by changing the concentration (mass, per unit volume), the inherent tendency to react may be incrcscd or decreased. 24. Water, a compound of hydrogen and oxygen, is widely distributed over the earth. 25. Natural radioactivity was discovered by the French physicist Henri Bccqucrcl (1851-1908) in 1896 just shortly after W. K. Roentgen’s discovery of X-rays in 1895.
    

26. 
    Different real gases have slightly different molar volumes. 27. The forces acting between atoms in a molcculc are very strong, and those acting between molcculcs arc weak. 28. The heat capacity of a substancc at, say, 25°C is not necessarily the same as that measured at another temperature.
    

29. 
    Covalency links arc those commonly met with in carbon compounds.
    
30. 
    Finely divided barium sulphate has a great tendency to absorb other ions from solutions.
    

Ex. 11. Translate the scntenccs into English without using a dictionary.

1. Для анализа раствора электролита необходимо знать, какие частицы находятся в нем. 2. Ионы электролита и новые ионы, полу­ чающиеся в результате взаимодействий в растворе, ведут себя по-разному. 3. Большое внимание уделялось изучению растворов за пос­ леднее время. 4. Еще в 1833 году был сделан вывод, что электролиз происходит посредством переноса электричества подвижными заря­ женными частицами. 5. Как водные, так и неводные растворы пред­ ставляют интерес для исследователей.
Ex. 12. Answer the following questions:
1. Why is it ncccssary to know the spccics present in solution? 2. Wh do the properties of cicctrolytc solutions depend on? 3. What knowledge helped chcmists to build up theories of solutions? 4. What fundamental conclusion made it possible to investigate cicctrolytc solutions successfully? 5. What processes take placc in electrolyte solutions?

Scction II

Упр. 1. Назовите значения следующих интернациональных слов:
postulate, ionization, dissociate, equivalent, association, neutral, opposite, specific, base, conccpt, statistical, attraction, interpret, polarize, identical, potential, dielectric, deviation, ideal, mobility, approximation
Упр. 2. Проверьте, помните ли вы значения следующих слов; если ист, обратитесь к словарю:
infinite, dilution, conform, assume, decrease, increase, valid, owing to, remarkably, distribute, seek (+ инфинитив), ascribe
Text 28 В
Прочтите текст про себя (контрольное время чтения— 3,5 минуты).
Ionic Theories
About the mid-1880’s, Arrhenius postulated in his ionization theory that (1) electrolytes are completely dissociated into their constituent ions in the limit of infinite dilution, (2) the equivalent conductance of the free ions is independent of concentration, (3) the equilibrium between the ions and the undissociatcd molcculcs conforms to the law of mass action. Thus, in the second postulate Arrhenius assumed that the decrease in conductivity with increasing concentration is due to the association of free ions to form neutral molcculcs. Wc now know that the original postulate is invalid sincc the mobility of the free ions decrease with increasing concentration owing to interaction between ions of opposite charge. In 1920, Bronstcd’s theory of specific ion interaction was based on the approximation that chemical interaction is limited to that between ions of opposite sign. By the reasoning given, it was shown that ions of the opposite chaigc arc more likely to approach close to one another than arc ions of the like charge, and this basic conccpt led to the considerable advances made by Brdnstcd in his own studies of mixed electrolyte solutions.
The first statistical theory of clcctrolytc solutions, the intcrionic attraction theory, was developed by Dcbyc and Huckcl in 1923 and its application has been remarkably successful in interpreting the behaviour of very dilute solutions. The ions arc regarded as unpolarizablc point chaigcs distributed in a continuum possessing a dielectric constant identical with that of the pure solvent, and it is also recognized that ions group themselves a little eloser around an ion of the opposite chargc than they do around ions of the like chargc. This leads to an ion atmosphere surrounding each ion in solution. From the theory, it is sought to calculate the average potential energy of a given ion in solution due to all the other ions, assuming the medium to have the dielectric constant of the pure solvent. In the argument strong electrolytes arc assumed to be completely

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dissociated into ions, and observed deviations from this ideal behaviour arc then ascribed to electrical interactions between the ions.
Упр. 3. Передайте основное содержание текста в нескольких пред­ ложениях.
Упр. 4. Какие слова в тексте означают «закон действия масс»? Упр. 5. Найдите в тексте ответы на следующие вопросы:

1. Каковы основные положения теории ионизации? 2. Чем, по мнению Аррениуса, объяснялось уменьшение проводимости при уве­ личении концентрации? 3. Какое допущение послужило основанием для теории Брснсгсда? 4. Какая теория наиболее успешно объясняла поведение разбавленных растворов? 5. Как объясняется поведение ионов в растворе на основе теории Дебая и Хюкксля?

Упр. б. Закончите следующие предложения:

1. 
   The original postulate suggested by Arrhenius is invalid bccausc...
   

2. 
   Bronstcd made considerable advances in... 3. The first statistical theory of cicctrolytc solutions was... 4. According to the theory developed by Debye and Hiickcl, an ion atmosphere surrounding each ion in solution is due to... 5. Using the theory by Debye and Hiickcl one can calculate...