Text 17 A Molecules in Gases and Liquids - раздел Образование, Part One THE PREDICATE According To Avogadro's Principle, Equal Volumes Of Gases Regardless Of Compo...
According to Avogadro's principle, equal volumes of gases regardless of composition, contain the same number of molccules at the same temperature and pressure. As a consequence of the principle, the gram- molccular weight of any gaseous substance occupics 22.4 litres at standard temperature (0°C) and pressure (760 mm of mercury). The number of molcculcs per gram-mole has been calculated by different methods of increasing refinement through the years, and is now considered to be 6.023xl0u atoms per gram-atom, or molecules per gram-mole), and it is accurate within 0.1%. For example, one mole of ammonia gas (NHj — weighs 17.073 grams, occupics a volume of 22.4 litre at standard temperature and pressure, and contains 6.023x102* molccules).
At the same temperature, molccules of a liquid move at the same rate as those in a gas. In a liquid, however, the extent of motion must be more restricted. Liquids flow as a stream and tend to form drops to a greater or less extent, thus giving evidence of the importance of the force of cohesion between the molccules in a liquid. Heating liquids, as a rule, results in their expansion, an effect explained by the tendency of the molcculcs to occupy more space when they move at a faster rate. Also, increase in pressure has but slight effect on the volume compressible. From this evidence it is argued that molcculcs in a liquid arc ajacent, close enough to flow in a continuous stream.
The molecules in a liquid, like those in a gas, are not all moving at the same velocity, but at the same average velocity at a given temperature. The molccules at the surfacc of a liquid, unlike those below the surface
layer, have no force of attraction from molcculcs above. Some of the more rapidly moving molcculcs overcome the cohcsivc force of their neighbour and leave the surface. The tendency to leave the surfacc or to evaporate varies from liquid to liquid, and it increases when the temperature is raised. The pressure causcd by the evaporation of molecules from a liquid, measured at equilibrium with the returning molecules at a given temperature, is callcd the vapour pressure. In general, vapour pressure increases when the temperature rises. With continued addition of heat the vapour pressure rises still more until the vapour pressure reaches the vapour pressure of the atmosphere above the liquid. The evaporation goes on throughout the liquid, and the liquid is boiling. Obviously the act of boiling can be accomplished either by raising the temperature of the liquid or by reducing the pressure of the atmosphere above the liquid.
Words and Word-Combinations to Be Memorized
accomplish, ammonia, attraction, average, compress, consequence, equal, equilibrium, evaporation, expansion, extent, fast, flow, go on, layer, litre, mercury, motion, the number of, obviously, occupy, overcome, per, pressure, principle, raise, rate, reducc, regardless of, restrict, result in, return, as a rule, stream, tend, tendency, throughout, unlike, vapour, velocity, weight
Ex. 5. Give the Russian equivalents for the following:
as a consequence of this principle, the gram-molecular weight, calculate by different methods, be accuratc within 0.1 %, move at the same rate, to a greater extent, give evidence of, the force of cohesion, from this evidence, flow in a continuous stream, below the surface layer, overcome the force, rise still more, throughout the liquid, accomplish the boiling, either... or..., 1 reduce pressure
Ex. 6. Give the English equvalents for the following:
равный объем, независимо от состава, одинаковое число молекул, при температуре, под давлением в одну атмосферу, быть ограниченным, в меньшей степени, таким образом, нагревание жидкости, как правило, приводить к, двигаться с большой скоростью, оказывать влияние на, со средней скоростью, при данной температуре, на поверхности жидкости, в отличие от, сила притяжения, тенденция к испарению, достичь атмосферного давления, продолжать нагревание, очевидно, или... или...
Ex. 7. Fill in the blanks with prepositions where necessary.
1. Liquids turn to form drops ... a greater or less extent. 2. One mole ... ammonia gas weighs... 17.073 grams, occupies a volume... 22.4 litres ... standard temperature and pressure. 3. The number ... molecules ... gram-mole was calculated... different methods. 4.... the same temperature,
molcculcs ... a liquid move ... the same rate as those ... a gas. 5. The cffcct ... increasing pressure ... the volume ... a liquid is only slight. 6. The tendency to evaporate varies ... liquid ... liquid. 7. ... general, vapour pressure increases when the temperature rises.
Ex. 8. Translate the sentences into Russian, paying attention to different functions of as.
I. As* conscquencc of Avogadro's principle, it is possible to determine the volume occupicd by the gram-molecular weight of any gaseous substancc at standard temperature and pressure. 2. Molcculcs of a liquid move at the same rate as those in a gas at equal temperatures. 3. Liquids can flow as a stream. 4. As a rule, there is a tendency of the molccules to occupy more spacc when they move at a faster rate. 5. As it was radicr late, they dccidcd to put off their work for the next day. 6. Technically, the process of obtaining oxygen is complicated as it requires one of the lowest temperatures used industrially -194.4°C. 7. As the hydrides of the alkali decompose in water, hydrogen is being released. 8. In the laboratory, hydrogen is made by the reaction of an acid such as sulphuric acid, H2S04, with a metal such as zinc. 9. Mcndclcycv is famous as the discoverer of the law of periodicity. 10. The molcculcs move faster as the temperature rises. 11. The explosion occurcd as the mixture was being heated.
Ex. 9. Translate the sentences into Russian.
1. Discussing the topic helped both of us to understand it better.
2. Working in the laboratory is the most important step in training chemists.
3. Professor N's participating in this confercncc attracted many other scientists. 4. His having made detailed notes at the lecture helped him to successfully pass the examination. 5. Our article being accepted in the Journal of Analytical Chemistry is a great honour to us. 6. There is no saying that the difference in temperature is too great. 7. Learning to work accurately is not an easy task. 8. Sometimes, preparing substances requires less skill than keeping them. 9. There is no denying that application of the quantum theoiy to chemistry stimulated its development. 10. Being very soft is characteristic of both calcium and sodium. 11. Lcbedcv's having prepared synthetic rubber paved the way to the synthesis of other materials. 12. Having examined the results led them to the conclusion that the structure of both compounds was alike. 13. Bohr's being awarded the Nobel prize was an international recognition of his great achievement. 14. Adding small quantitcs of other substances to alloys changes their properties, sometimes to a great extent. 15. Their coming to St. Petersburg was quite unexpected. 16. Investigating the weights and properties of elements led him to the discovery of his world-known law.
Ex. 10. Translate the sentences into English.
1. Закон Авогадро утверждает, что равные объемы различных газов содержат одинаковое количество молекул при одинаковых тсм- пературе и давлении нсависнмо от состава. 2. При одинаковой температуре средние скорости движения молекул жидкости и газа одинаковы. 3. Нагревание тела, как правило, приводит к увеличению его объема. 4. Как у жидкости, так и у газа не все молекулы движутся с одинаковой скоростью при данной температуре. 5. Тенденция к испарению увеличивается, когда повышается температура. 6. Нельзя сказать, что все жидкости испаряются с одинаковой скоростью. 7. Точка кипения жидкости определяется температурой и давлением.
Ex. 11. Answer the following questions:
1. What does Avogadro's principle state? 2. In what way can the number of molcculcs per mole be determined? 3. What forces act between the molcculcs in a gas and in a liquid? 4. What affccts the molecular motion? 5. What process is called evaporation? 6. What is the vapour pressure? 7. What does the boiling point of a liquid depend on?
Section II
Упр. 1. Назовите значения следующих интернациональных слов:
container, limit, crystalline, vibration, oscillation, ciystal, phenomenon, sublimation, dioxide, camphor, sublime, coulomb, graphite, hexagonal, hexagon, associate, fix
Упр. 2. Определите значения выделенных слов по контексту.
1. Water turns into ice at 0°C. 2. The temperature at which a solid changes into a liquid is called its melting point. 3. Repeat the rule several times, then you will remember it. 4. H2S04 is apparently* more complcx s compound than H2S.
Оюва к тексту:
shape—форма; bound — ограничивать; dihedral — образованный двумя плоскостями, гранями; confine — ограничивать; dry — сухой; tie — связывать
Text 17 В
Прочтите текст про себя (контрольное время чтения — 4 минуты). Molecules in Solids
Having their own shape is a characteristic feature of solids since they have their own shape rather than that of the container (as for liquids and gases) and generally do not flow, the extent of molecular motion in a solid is even more limited than that in a liquid. True solids are crystalline, bounded by plane surfaces that meet in a definite dihedral angle, and have a characteristic melting point. The molcculcs in a solid have the same temperature, and if they are molecules of the same
substancc, they arc moving at the same average velocity, the motion of molcculcs in a solid must be confined, and, probably, it is a vibration or oscillation about a fixed point.
Crystals composed of molecules may evaporate in a manner similar to that of liquids. This phenomenon is called sublimation, and it may.be noticed in solid carbon dioxide (dry ice), paradichlorobcnzcnc, camphor, and many odorous solids. Non-molccular solids show little tendency to sublime. The Van dcr Waals force between the particles in molecular solids is, apparently, less in general than the coulomb forces between ions in non-molccular solids. As with liquids, solids vaiy greatly in their tendency to sublime, and the rate of sublimation varies with the temperature and inversely with the pressure. In some solids the ciystal is composed of molecules in a pattern Uiat repeats.
Упр. 3. Передайте основное содержание текста в нескольких предложениях.
Упр. 4. Составьте план текста.
Упр. 5. Прочтите предложения н скажите, соответствуют ли онн содержанию текста. Если нет, исправьте их.
1. Liquids and gases usually have the form of their container.
2. Characteristic feature of solids is that they have their own form.
3. Crystalline solids cannot evaporate like liquids. 4. Sublimation is the evaporation of solids. 5. The rate of sublimation increases with the rise of the temperature and the pressure. 6. Planar structure of the carbon atoms in graphite makes its properties different from those of a diamond.
Упр. б. Найдите в тексте и переведите на русский язык предложения, в которых говорится о движении молекул внутри вещества.
Section Ш
Ex. 1. Answer the questions, using the verb make.
1. When arc you going to make calculations? 2. Who advised you to make this approach to the problem? 3. Have you finished making your measurements? 4. Do you make many mistakes in your English? 5. Don't you remember when Mendeleyev made his greatest discovery? 6.1 think he won't make use of this law and what about you? 7. His lecture made a deep impression on me, and what about you? 8. How long did it take you to make your experiment?
Ex. 2. Translate the sentences into English.
1. Я думаю, необходимо еще раз провести расчеты. 2. Она всегда делает ошибки в чтении. 3. Наш лектор — большой ученый, он сделал важное открытие в физической химии. 4. Сначала вам надо изучить литературу по этому вопросу. 5. Никто не пользуется этим при
бором сейчас, вы можете выполнить свои измерения. 6. Она внссла предложение поехать за город вместе. 7. Он произвел на нас очень хорошее впечатление.
Ex. 3. Make up short dialogues according to the model.
Model: — A request.
— An answr. (+, -)
— Give me your pen, please.
— Here you are. (Sorry, but Vm writing just now.)
Ex. 4. Give detailed answers to the following questions:
1. What is the essence of Avogadro's principle? 2. In what way can Avogadro's principle be used? 3. What do you know about the molecular motion? 4. What is the principal diiTcrcnce between gases, liquids and solids? S. What is the diiTcrcnce in properties between crystalline and non-crystalline solids?
Ex. 5. Discuss the following topics:
1. The Characteristic Features of Gases, Liquids and Solids.
2. The Difference of the Molecular Motion in Various States of a Substancc.
3. The Influence of the Temperature and the Pressure on the State of a Substancc.
WHAT IS IT?
A compound of oxygen and another element (metallic or non-metallic).
Все темы данного раздела:
Fluorine
Fluorine, the lightest of the halogens, is the most rcactivc of all the elements, and it forms compounds with all the elements cxccpt the lighter inert gases. This great reactivity may be attribute
Lesson 10
ГРАММАТИКА: Формы н употребление сослагательного наклонения.
Section I
Ex. 1. Pronounce the following words:
С + e, i,y
M
Text 10 В
Прочтите текст про себя (контрольное время чтения — б минут). Uses of Indium
Indium finds most of its uses as an addition to other materials for the purpose of obtaining more desirable pro
Lesson 11
ГРАММАТИКА: Употребление и перевод глаголов may, might, could, ought в сослагательном наклонении.
Scction I
Ex. 1. Pronounce the following words.
pb
Fascinating Phosphorus
Phosphorus is one of the most interesting of all the elements. Its peculiar property of glowing in the dark places it in a special and rare category. For some unexplained reason, man has always bee
Modifications of Phosphorus
Yellow Phosphorus. Phosphorus may occur in three allotropic forms: yellow, violet, and black. However, the two most common forms arc yellow and red. There can be traccd a difference of opinion as t
Lesson 12
ГРАММАТИКА: Повторение темы «Сказуемое».
Section I
Ex. 1. Pronounce the following words:
Помните, что в многосложных словах ударение часто падает на 3-й слог от конца сло
Chemical Symbols for Representing Compounds
It is a short step from using a symbol for an element to using a formula for a compound. However, it is often forgotten that die very act of writing the formula for a compound assumes the law of co
Weight of У12 atom of carbon 12
can be measured experimentally. Therefore the formula NHj can either refer to one molcculc of ammonia, containing one atom of nitrogen, and three atoms of hydrogen, or, alternatively, to one gram-m
Lesson 13
ГРАММАТИКА: Подлежащее. Существительное в функции подлежащего. Местоимение в функции подлежащего.
Section I
Ex. 1. Practise your pronunciation.
a) period ['pionod], anci
Text 13 A The History of Chemistry
There arc five periods in the history of chemistry. The ancient period comprising the older civilizations of China, India, Greece, and their contemporaries to 350 A. D. developed practical arts as
Text 13 В
Прочтите текст про себя (контрольное время — 4 минуты). New Frontiers in Chemistry
Twenty-first-ccntury chemistry has narrowed into units such as instrumental analysis, biochemistry, chemi
Lesson 14
ГРАММАТИКА: Оборот «именительный падеж с инфинитивом».
Section I
Ex. 1. Practise your pronunciation.
a) thought [0o:t], continuous [kon'tinjoos], surfacc ['s3:fis], argue
Text 14 A The Idea of the Atom
Many times during the coursc of history men believed that the solid matter, of which the different things in the world arc made, was really continuous matter. They thought that if you could look at
Text 14 В
Прочтите текст про себя (контрольное время чтения — 3 минуты). The Atomic Theory of Democritus and Dalton
The Greek philosopher Democritus (about 460-370 B.C.) who had adopted some of his
Lesson 15
ГРАММАТИКА: Некоторые особенности перевода на русский язык оборота «именительный падеж с инфинитивом». Оборот «именительный падеж с причастием, прилагательным, числительным».
Section I
Text 15 A The Atomic Theory
In 180S the English chemist and physicist John Dalton (1766-1844) put forward the hypothesis according to which all substanccs were stated to consist of small particles of matter, of several differ
Text 15 В
Прочтите текст про себя (контрольное время чтения — 3 минуты). The Bohr Theory of the Hydrogen Atom
Most our knowledge of the electronic structure of atoms has been obtained by the study o
Lesson 16
ГРАММАТИКА: Инфинитив и инфннитивный оборот в функции подлежащего.
Section I
Ex. 1. Practise your pronunciation.
a) molcculc ["mohkju:!], peculiar [pi'kjuiho], rear
Text 16 A Molecules
To the modern chcmist, the atom is the smallest particle of an clement that can enter into a chcmical reaction. Thus, each clement has atoms that are peculiar to itself and different from those of
Molecular Composition and Size
Molecules are chemical units composed of one or more atoms. The simplest molecules contain one atom each; for example, helium atoms (one atom per molecule) arc identical with helium molccules. Oxyg
I Section I
Ex. 1. Practise your pronunciation.
a) equal ['i.kwolj, pressure ['prcjo], consequence ['konsikwons], gaseous ['gasidsj, weight [weit], cohesion [кэо'Ы.зэп], adjacent [o'dseisont], average
Lesson 18
ГРАММАТИКА: Придаточное предложение в функции подлежащего.
Scction I
Ex. 1. Practise your pronunciation.
a) iodine faiodirn], equilibrium [ ,i:kwi'libnom], fluidity [flu'
Text 18 A The Nature of a Liquid
When iodine crystals arc heated to 114°C, they melt forming liquid iodine. The temperature at which the crystals and the liquid arc in equilibrium — that is, at which crystals have no tendency to m
Text 18 В
Прочтите текст про себя (контрольное время чтения — 3 минуты). The Nature of a Gas
That the molcculcs of a gas arc not held together, but arc moving freely in a volume rather large compare
Lesson 19
ГРАММАТИКА: Место дополнения в предложении. Существительное и местоимение в функции дополнения.
Section I
Ex. 1. Practise your pronunciation.
a) originally [o'ridsonoh],
The Study of the Structure of Molecules
The study of the structure of molcculcs was originally earned on by chemists using methods of investigation that were essentially chcmical in nature, relating to the chemical composition of a subst
Lesson 20
ГРАММАТИКА: Инфинитив и инфинитивный оборот в функции дополнения.
Section I
Ex. 1. Practise your pronunciation.
a) covalent [koo'veilont], distribute [dis'tribjot], elec
The Structure of Covalent Compounds
The clcctronic structure of molcculcs of covalcnt compounds involving the principal groups of the periodic table can usually be written by counting the number of valcncc electrons in the molcculc a
Covalcncc
Many compound substanccs do not have particularly high melting and boiling points, do not conduct electricity when they arc molten, and, thus, give no indication of being ionic. The particlcs of su
Lesson 21
* ГРАММАТИКА: Причастный оборот в функции дополнения.
Section I
Ex. 1. Practise your pronunciation.
a) require [n'kwaid], completion [kom'pli'Jon], extremely (iks'tri:mh]
Factors Influencing the Rate of Reactions
Eveiy chemical reaction requires some time for its complctiQn, but some reactions arc very fast and some arc very slow. Reactions between ions in solution without changc in oxidation state arc usua
A Catalyst
A catalyst is a substancc that alters the speed of a chcmical reaction without itself undergoing any chcmical change, usually only a small quantity of it is required.
Catalysts arc usually
Lesson 22
ГРАММАТИКА: Герундий и герундиальный оборот в функции дополнения.
Section I
Ex. 1. Practise your pronunciation.
a) determine [df t3:min]f prevail [pn'veil], co
Text 22 A Factors Affecting the Boiling Point
The temperature at which a liquid boils, is dependent not only upon the nature of the liquid itself, but also upon the pressure prevailing at the time the boiling point is determined. An increase i
Text 22 В
Прочтите текст про себя (контрольное время чтения—4,5 минуты). Temperature Scales
If two objects are placed in contact with one another, thermal energy may flow from one objcct to the othe
Lesson 23
ГРАММАТИКА: Придаточное предложение в функции дополнения.
Section I
Ex. 1. Practise your pronunciation.
a) measure ['тезэ], centigrade ['scntigrcid], advance [od'va:ns],
Text 23 A Celsius versus Centigrade
The Ninth General Conference on Weights and Measures, held in October, 1948, adopted the name "Celsius" for the scalc of temperature which had more commonly been callcd "ccntigradc&q
The Kelvin Temperature Scale and Modern Means of Measuring the Temperature
About 200 years ago scientists noticed that a sample of gas that is coolcd decreases in volume in a regular way, and they saw that if the volume were to continue to dccrcasc in the same way, it wou
Gas Thermometer
The establishment of the International Temperature Scalc has required that the thermodynamic temperatures of the fixed points be determined with as much accuracy as possible. For this purpose a dcv
Lesson 24
ГРАММАТИКА: Повторение тем «Подлежащее» и «Дополнение»
Section I
Ex. 1. Practise your pronunciation.
a) recognize ['rckognaiz], relative ['relotiv], carefully ['kcofuli],
The Composition and Structure of Water
Water was thought by the ancients to be an clement. Henry Cavendish in 1781 showed that water is formed when hydrogen is burned in air, and Lavoisier first recognized that water is a compound of th
Lesson 25
ГРАММАТИКА: Определение. Прилагательное, местоимение, существительное, наречие в функции определения.
Scction I
Ex. 1. Practise your reading.
The subject of acids and ba
Text 25 A Bases
The subject of acids and bases has long been one of the most controversial in chcmistry, and led to the development of an interesting series of theories.
In the 17th century, during t
The Arrhenius Theory of Acids and Bases
There is perhaps no other class of equilibria as important as that involving acids and bases. As wc continue the study of chcmistry, wc shall find that the classification "acid-base reaction&q
Lesson 26
ГРАММАТИКА: Герундий и герундиальный оборот в функции определения. Причастие и причастный оборот в функции определения. Инфинитив после причастия II и слов likely, sure, certain.
Section
Text 26 A Liquids and Solutions
Solids and gases represent the extreme states of behaviour of molcculcs. The liquid state can be thought of as an intermediate condition in which some of the properties found in cither solids or ga
Lesson 27
ГРАММАТИКА: Инфинитив и инфинитивный оборот в функции определения. Придаточное предложение в функции определения.
Section I
Ex. 1. Practise your reading.
It is often tr
Text 27 A The Properties of Solutions
It is difficult to give a definition which tells clcarly and briefly how <r solutions differ from mixtures and compounds, in spite of the fact that solutions arc among the most familiar substanc
Text 27 В
Прочтите текст про себя (контрольное время чтения — 3 минуты). Types of Solutions
Just as the variables, pressure, volume, and temperature, were used to describe the state or condition of
Lesson 28
ГРАММАТИКА: Обстоятельство. Существительное, наречие, герундий и герундиальный оборот в функции обстоятельства.
Section I
Ex. 1. Practise your reading.
As long ago as 183
Interactions in Electrolyte Solutions
In a solution of an electrolyte, 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 qu
Text 28 В
Прочтите текст про себя (контрольное время чтения—3,5 минуты). Ionic Theories
About the mid-1880's, Arrhcnius postulated in his ionization theory that (1) electrolytes arc completely disso
Lesson 29
ГРАММАТИКА: Причастие и причастный оборот в функции обстоятельства. Независимый причастный оборот.
Section I
Ex. 1. Practise your reading.
The temperature remaining cons
Text 29 A Liquid-Vapour Equilibrium
A liquid of relatively low boiling temperature, when placed in a container open to the atmosphere, will eventually evaporate entirely. Remembering that molcculcs in the liquid arc "bound&
Temperature Dependence of Vapour Equilibrium
Experimental measurements show that the equilibrium vapour pressure of a liquid increases as the temperature increases. In the temperature range in which the vapour pressure is small, it is relativ
Lesson 30
ГРАММАТИКА: Инфишпив и инфинитивный оборот в функции обстоятельства. Придаточные обстоятельственные предложения.
Section I
Ex. 1. Practise your reading.
It is a matter o
Text 30 A Solubility
While there arc many pairs of substanccs which, like water and tfthyl alcohol, can be mixed in any proportions to form homogeneous solutions, it is a matter of common experience that the capacity o
Nonideal Solutions
Consider a solid substancc dissolving in a liquid solvent. The solid is such that when melted, it is converted to a liquid that, in turn, can form an ideal solution with the solvent. The dissolutio
Lesson 31
ГРАММАТИКА: Вводные члены предложения. Инфинитив и причастие в функции вводного члена предложения.
Section I
Ex. 1. Practise your reading.
The terms "oxidation"
Text 31 A Oxidation and Reduction
Generally speaking, the simple meanings of these terms arc that oxidation is the addition of oxygen to a substancc and reduction is the
removal of oxygen. Needless to say, hydrogen se
Text 31 В
Прочтите текст про себя (контрольное время чтения — 3 минуты). Original Meanings of Oxidation and Reduction
Prior to the discovery of oxygen independently by Scheclc of Sweden in 1771-1772
Lesson 32
ГРАММАТИКА: Эмфатические конструкции. Усилительное do. Эмфатические конструкции типа It is... that...
Scction I
Ex. 1. Practise your reading.
It was largely analytical c
Analytical Chemistry — the Oldest Field of Chemistry
Analytical chcmistiy is probably the oldest field in the broad spectrum of the scicncc of chcmistry. Many years were required to dispel the lure of alchcmy; more were needed to demonstrate the fall
Two Branches of Analytical Chemistry
The relatively small chcmical manufacturing plants producing such chcmicals as alkalis, sulphuric acid, ctc., indeed, some of the factories making consumer goods and employing chcmicals in the proc
Lesson 33
ГРАММАТИКА: Эмфатические уступительные предложения.
Section I
Ex. 1. Practise your reading.
Gradually, chemists began synthesizing some things found in nature and later t
Text 33 A Classical Methods of Analysis
Strange as it may seem now, the analyst and the "works chemist" of the 18th and 19th ccnturics depended almost entirely on what arc frequently defined today as the classical methods of an
Text 33 В Modern Methods of Analysis
Прочтите следующий текст про себя (контрольное время чтения — 3 минуты).
The so-called classical gravimetric and volumctric methods have by no means been superseded by physical chcmistry a
Lesson 34
ГРАММАТИКА: Различные случаи инверсии.
Scction I
Ex. 1. Practise your reading.
Used in the design and interpretation of chcmical experimentation are various statistical m
Statistical Methods in Analytical Chemistry
Statistical methods, as used in the design and interpretation of chcmical experimentation, arc not a substitute for common sense or for what scientists refer to as scientific judgement; they rather
Lesson 35
ГРАММАТИКА: Предложения с парным союзом the... the... . Двойное отрицание.
Scction I
Ex. 1. Practise your reading.
When a solid is heated to incandescence, it emits more
Text 35 A Investigations of Spectra
The more profound is the investigation of the structure of atoms and molcculcs, the more problems arise. It was not long ago that consideration of the cxtra-nuclcar clcctrons was rcstrictcd to
Text 35 В
Прочтите текст про себя (контрольное время чтения — 3 минуты). Who Is the Discoverer of Spectrum Analysis?
The more detailed is the scrutiny of the history of chcmistry, the greater is the
Lesson 36
ГРАММАТИКА: Обшсе повторение.
Section I
Ex. 1. Practise your reading.
The guiding light of theory must be confirmed by the bench of physical manipulation.
Ex. 2.
Lesson 36
ГРАММАТИКА: Обшсе повторение.
Section I
Ex. 1. Practise your reading.
The guiding light of theory must be confirmed by the bench of physical manipulation.
Ex. 2.
Why Study Chemistry?
Certainly, the student who has had one year of chcmistry remembers virtually no detail after a few months. The things that stick will generally include some notion of atomic structure, and this inf
Conductance and Electrolysis
Generally speaking, the classification of a substance as a non-clcctrolytc or as an clcctrolytc is based on the conductance of its aqueous solution. Aqueous solutions of non-clcctrolytcs do not con
Text 2 Library and You
Because of the vast accumulation of data, today's student of chcmistry must rely on the literature more than ever before; it is therefore to his advantage to bccomc acquainted with the organization
Text 3 Infrared Spectroscopy
Infrared spectroscopy resembles Raman spectroscopy in that it provides information on the vibrational and rotational energy levels of a spccics, but it differs from the latter technique in that it
Nuclear Magnetic Resonance
The nuclei of atoms can be likened in some respects to. elementary magnets. In a strong magnetic field, the different orientations that the elementary magnets assume correspond to different energie
Text 5 Gold
Perhaps no other metal has played such an important part in the destiny of man as gold has. For ccnturics, it has stood as a barometer of wealth and nobility. To secure it, men have fought, suffere
Text 6 Actinium
Radioactive transition metal of Group III. Atomic number 89. Symbol Ac. All isotopes arc radioactive; atomic weight tables list the atomic weight as [227], the mass number of the most stable isotop
Radiation Effects on Polymers
Radiation exerts two opposing cffccts on polymers. On the one hand, it breaks up the polymer molcculcs into smaller picccs. On the other, it causes liberation of a hydrogen atom from cach of the tw
Radiation Effects on Polymers
Radiation exerts two opposing cffccts on polymers. On the one hand, it breaks up the polymer molcculcs into smaller picccs. On the other, it causes liberation of a hydrogen atom from cach of the tw
Insulator Itirns into Superconductor
Having used ultrahigh pressures and critically low temperatures, scientists at the Institute of High Pressures of the USSR Academy of Sciences have managed to cffcct such a unique transformation as
Text 10 Salt Shaker Wedding
On Friday evening, April 13, at five o'clock, Miss Chlorinc Halidc became the bride of Mr. Sodium Alkali in a double beaker ccrcmony at the Little Church of Mother Nature. Rev. Elcctro Valcncc perf
The Role of Theory in Chemistry
We start at the beginning and define science as a set of observations and theories about observations. Wc then define theory as a device for making predictions and correlations of observations. A t
Theories of Matter
There is a wide varicly of chcmical and physical theories from which wc select as our example theories of matter (atoms, molcculcs, solids, nuclei, and elementary particles). Wc can illustrate the
Molecular Theory
Matrix mechanics theory of matter (MMTM) is a better molecular theory than the ball-and-stick molccular theory. In thcal> initio MMTM molecular theory the only parameters required by the procedu
Differentiating between Primary, Secondary, and Tertiary Alcohols
A primary or secondary aliphatic alcohol dissolved in pure glacial acetic acid decolourizes a water solution of KMnO*, while a tertiary alcohol fails to do so. A secondary alcohol will continue to
A Brief History of Polypeptide Chemistry
Protein chcmistry really began in the 1830s with Mulder's systematic investigation of nitrogenous biological materials, such as blood fibrin, egg white, gelatins, and silk. In 1840, Huncfeld was th
Characteristics of Mossbauer Spectra
To obtain a resonant gamma-ray absorption spectrum it is ncccssary to relate the transmission intensity to the instantaneous source-absorber velocity. In practice there arc a number of methods whic
Text 17 Free Radicals
An atom or group of atoms with one or more unshared electrons, which may enter into chemical-bond formation is callcd a free radical. (The same group in a molcculc is called a radical; for example
The Manufacture of Sulphuric Acid
It is a matter of common knowledge among chemists that sulphuric acid is made by two processes, the contact proccss and the lead-chamber proccss, which arc now about equally important.
In
What Is Light? What Is an Electron?
During rcccnt years many people have asked the following questions: "Docs light really consist of waves or of particles? Is the electron really a particlc, or is.it a wave?"
Thes
Text 20 The Nature of Resonance
The idea of resonance has brought clarity and unity into modern structural chcmistry, has led to the solution of many problems of valence theory, and has assisted in the correlation of the chcmical
Benjamin Franklin and Electricity
January 17,2006, will be the 300th anniversary of the birth of Franklin.
Kant once remarked that Benjamin Franklin was a new Prometheus who had stolen fire from heaven. In his own day, Fra
Text 22 Future Perspectives
The production of protein from chemicals is not the only proccss one can employ for converting chemicals to food, but it is representative of one major type of proccss: fermentation. Microorganisms
Gas Chromatography Methods
Gas chromatography (GC), or, more recently, gas-liquid chromatography, is based on the volatilization of thermally stable analytcs which have a vapour pressure of approximately 0.1 mm or greater a
Liquid Chromatography Detectors
During the last years, there has been a marked increase of interest in column liquid chromatography (LC). One reason that this technique, whose discovery preceded gas chromatography (GC) by many ye
Miscellaneous Grammar
Translate the sentences into Russian.
1. The work referred to also brought to light many examples of abnormal behaviour. 2. Having examined it carefully, wc found out that the gas under in
Words a Student Should Know before Studying the Textbook
a[10]
about* above active after
afternoon
in the afternoon again against ago agree all* alo
Struggle
student
study
suit
summer
in summer sun
Sunday supper swim
table take
take part in tea teach teacher tell ten tenth
that* (th
Chemical Elements
Ac
actinium
(rck'tiniom)
актиний
Ag
silver
j'sdvoj
серебро
Word-building
В английском языке словопроизводство (derivation), т. е. образование одного слова из другого, является самым распространенным способом образования слов.
Образование одного слова из другог
Общие схемы образования производных слов
{ Г"
anion cation
I i
ion
an
Irregular Verbs
arise
arose
arisen
возникать
be
was, were
been
быть, являться; находиться
Новости и инфо для студентов