Chemical Kinetics And Nikolay Semyonov

Chemical kinetics Warm up Answer the following questions. 1. Do you know how chemical reactions occur? 2. What conditions are important to the speed of the reaction? 3. Can any conditions be altered during the reaction? 4. What are the three different states of matter? 5. What is salt made up of? 6. What state does salt exist in?

7. What is a chain made up of? 8. What do you think a chain reaction is? 9. How much do you know about atomic science? 10. What do you think of it (atomic science)?

Vocabulary work a. Match these words with their definitions 1. rate A decay В spring back like a ball 2. consumed С moment 3. rot D as if eaten up 4. collide E the speed at which something happens within a 5. catalyst particular period of time F one moving object crashes into another 6. bounce G strength and power 7. instant H enough 8. compressed I pushed hard together 9. force J a substance that without being affected increases speed of chemical reaction 10. sufficient b. Complete the definitions below with words from the box. thermal explosion by-product analysis transformation primary reactive

expertise field external phenomenon sequence additional

1. A(n) ………………………………… is what is produced as a secondary result of a process. 2. ………………………………… means outer. З. A(n) ………………………………… is an area where a particular force has an effect. 4. ………………………………… means added to. 5. ………………………………… is the process of examining something in order to understand it. 6. A(n) ………………………………… is a series of events, one after the other. 7. A(n) ………………………………… is a complicated chemical process involving heating which leads to exploding. 8. A(n) ………………………………… is any state or process understood according to the senses rather than by reasoning. 9. Repairing the nuclear reactor is our ………………………………… concern at the moment. 10. The surgeon’s medical ………………………………… saved the man’s life. 11. Not all chemical substances are ………………………………… 12. How is the ………………………………… of wood into ash explained? Reading Comprehension 1 Play out the following dialogue Student 1: How's your Chemistry class going? Are you enjoying it? Student 2: I'm enjoying the lab work – the experiments are really good - but I'm having trouble understanding the theory and some of the terms. You did Chemistry last year. Can you help me? Student 1: Sure. What's the problem? Student 2: Well, let's start with chemical reactions. What exactly are they?

Student 1: A chemical reaction is a process that changes substances. The substance or substances that you start with are called reactants. Student 2: ... and the substances that are produced are called products. Student 1: Right. And during a chemical reaction energy is released or absorbed, but there's no change in the total molecular weight - that remains the same. OK? Student 2: Urn ... I'm not sure. Can you give me an example? Student 1: Yes. Let's look at salt, whose chemical name is sodium chloride. Suppose we start with x weight of salt. Student 2: OK. Student 1: Now, let's take that salt and decompose it - that means 'break it down'. Its molecules, which consist of equal parts of sodium and chloride ions, are broken down. The sodium atoms then combine in pairs to form sodium molecules, and the chloride ions combine to form chlorine molecules. Now, instead of salt, you have two different elements. Student 2: And those two elements' combined weight will be the same as the weight of the salt? Student 1: Exactly. Also, in a chemical reaction, substances lose their characteristic properties. Salt, for example, is a solid in crystal form, right? Student 2: Right... Student 1: ... but in decomposing it, we have produced a metal and a gas... Student 2: ... a metal and a gas? Student 1: Yes. Sodium is a metal and chlorine is a gas. Student 2: OK. Student 1: ... so, from a crystal solid - salt - we have produced a metal and a gas. Student 2: OK, I get it. I think. In a chemical reaction, substances combine to form new substances; molecular weight doesn't change -, and the characteristic properties of substances can change. Student 1: Very good! Decide if the following statements are true or false. Correct the false statements 1. A chemical reaction begins with reactants. T / F …………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………… 2. Weight is released in a chemical reaction. T / F …………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………… 3. Salt is a metal. T / F …………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………… 4. Sodium and chlorine are solids. T / F …………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………… 5. In a chemical reaction combined substances make new ones. T / F …………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………… Reading Comprehension 2 Read the following text and do the activities after it. CHEMICAL KINETICS Chemical kinetics is the study of rates of chemical reactions. In the world around us billions of chemical reactions occur; some are incredibly slow while others are amazingly fast. It can take years for wood to rot, while the lighting of a match takes just an instant. Chemical kinetics attempts to understand the factors that control the rates of chemical reactions. These factors are concentration, pressure, surface area, the nature of the reacting substances, temperature and catalysts. In general, increasing the concentration of the reacting substances increases the reaction rate. This is because molecules must collide in order to react. The more concentrated the reacting substances, the more molecules there will be in any given volume, and therefore, the greater the number of molecular collisions.

If the substances involved in the reaction are gases, pressure will have an effect on reaction rate. Solids and liquids can not be compressed, but gases can, so pressure acts as a kind of concentration for gases. The volume of a gas decreases as the pressure increases. For a given amount of gas, increasing the pressure means we are forcing the same number of gas molecules to occupy a smaller volume. In the smaller volume, the molecules will collide more often, which means there will be a greater number of successful collisions in a given period of time. Reaction rate increases with pressure. If a chemical reaction takes place at a boundary between two states (gas, liquid or solid), the surface area will affect the reaction rate. Only the molecules at the surface area are available to react, so increasing the surface area increases the number of molecules that are able to react, and this leads to a higher reaction rate. Some substances are naturally more reactive than others. For example, if the metals magnesium, zinc and copper are dropped into hydrochloric acid in separate test tubes, three very different results are obtained. The magnesium is consumed within seconds, the zinc is consumed but takes much longer, and the copper shows no reaction. Therefore, magnesium is more reactive than zinc and copper. Temperature affects the rate of a chemical reaction in two ways. Firstly, molecules move faster in a hot system than in a cold one, so they will collide more often if they are moving faster. Secondly, increasing the temperature increases reaction rate through its effect on the collision energy (known as activation energy) of the molecules. Molecules must collide with sufficient force in order to combine and produce a chemical reaction. Higher temperatures give molecules the energy to collide forcefully. If they collide with less than a certain amount of energy, they simply bounce off of each other unchanged. Finally, a catalyst is a substance that increases the rate of a chemical reaction without being consumed in the reaction. It increases the reaction rate by reducing the activation energy, that is, the minimum amount of energy that the reacting molecules must have in order to react. a. Choose the correct answer 1 The rate of a chemical reaction A depends on different factors. В is very fast for metals. С is always the same. 2 In order for a chemical reaction to occur A the volume of a gas must increase. В solids must be compressed. С molecules must collide. 3 Higher concentrations of reacting substances will lead to A more chemical reactions. В increased pressure. С reactive products.

4 The metal zinc A is more reactive than magnesium. В reacts more slowly than magnesium. С is less reactive than copper. 5 Higher temperature can make molecules A travel faster with no increase in energy. В travel at the same speed, but with more energy. С travel faster, and with more energy.

b. Circle True (T) or False (F) according to the text? Correct the false statements 1. Pressure acts as a kind of concentration for all the substances: solids, liquids, and gases. T / F ........................................................................................................................................................ ................ ........................................................................................................................................................ ................ 2. Increasing the surface area increases the number of molecules that are able to react, and this leads to a higher reaction rate. T / F ........................................................................................................................................................ ................ ........................................................................................................................................................ ................ 3. A catalyst is a substance that increases the rate of a chemical reaction being itself consumed in the reaction. T/F

........................................................................................................................................................ ................ ........................................................................................................................................................ ................ c. Answer the following questions by referring to the reading text 1. Which factors does chemical kinetics attempt to understand? Which are these? ........................................................................................................................................................ ................ ........................................................................................................................................................ ................ 2. How does temperature affect the rate of a chemical reaction ? ........................................................................................................................................................ ................ ........................................................................................................................................................ ................ Translation Skills Translate the following sentences into your native language. 1 The study of reaction rates and reaction mechanisms is known as chemical kinetics. ........................................................................................................................................................ ................ ........................................................................................................................................................ ................ 2 The rate of a reaction depends on the concentration of the reacting substances, the temperature, the presence of catalysts and the nature of the reactants. ........................................................................................................................................................ ................ ........................................................................................................................................................ ................ 3 A change in the concentrations of the substances will change the number of molecular collisions. ........................................................................................................................................................ ................ ........................................................................................................................................................ ................ 4 If the substances involved in the reaction are gases, pressure will have an effect on reaction rate. Reaction rate increases with pressure. ........................................................................................................................................................ ................ ........................................................................................................................................................ ................ 5 Increasing the surface area where a chemical reaction takes place, increases the reaction rate. ........................................................................................................................................................ ................ ........................................................................................................................................................ ................ 6 An increase in temperature generally increases the rate of reaction. ........................................................................................................................................................ ................ ........................................................................................................................................................ ................ 7 A catalyst is a substance that influences the rate of the reaction. ........................................................................................................................................................ ................ ........................................................................................................................................................ ................

FAMOUS PEOPLE Nikolay Semyonov Nikolay Semyonov, a physicist and chemist, and a leader of the Soviet nuclear weapons programme, was born on 15th April, 1896, and died on 25 th September, 1986 in Moscow. His primary scientific contributions are related to the quantitative theory of chemical chain reactions, the theory of thermal explosion, and the burning of gaseous mixtures. He was a Physics graduate of Petrograd (St Petersburg) University, and in 1920 he was put in charge of the electron phenomena laboratory of the Phvsico-Technical Institute in Petrograd. It was at this time, while working with Pyotr Kapitsa, that he discovered a way to measure the magnetic field of an atomic nucleus. In 1931, he became Director of the Institute of Chemical Physics of the USSR Academy of Sciences, and from 1944 he was a professor at the Moscow State University. For his work on the mechanism of chemical transformation, he was awarded the 1956 Nobel Prize for Chemistry. Semyonov's work on the mechanism of chemical transformation includes an important analysis of the application of the chain theory (a sequence of reactions where a reactive product or by-product causes additional reactions) to different reactions, particularly combustion processes. In chemistry and physics, a chain reaction is a reaction that, once started, continues without further outside influence. Proper conditions for a chain reaction depend not only on various external factors, such as temperature, but also on the quantity and shape of the substance in the reaction. A chain reaction can be of various types, but nuclear chain reactions are the best known, and it was in this particular area that Semyonov contributed his expertise to the nuclear weapons programme. He also made valuable contributions to the field of molecular physics and electron phenomena. Semyonov published his work in three important books. The first was Chemistry of the Electron, published in 1927. This was followed by Chemical Kinetics and Chain Reactions in 1934, which was the first book in the USSR to propose a theory of chain reactions in chemistry. Further studies in chemical kinetics led to the publication, in 1954, of Some Problems of Chemical Kinetics and Reactivity, which was translated into many languages. Semyonov received many awards and honours in his lifetime, including five Orders of Lenin. He was a member of the Chemical Society in London, Foreign Member of the Royal Society and Foreign Member of the American, Indian, German, and Hungarian Academies of Sciences. He held honorary doctorates from the University of Oxford and Brussels University. I. Choose the best title for each paragraph. There is one title which you do not need to use. PARAGRAPH PARAGRAPH PARAGRAPH PARAGRAPH PARAGRAPH PARAGRAPH

1 2 3 4 5 6

II. Ask 10 questions to the text

A Scientific career В Lifetime recognition С Basic facts D Famous author E The highest honour F The combustion process G Explanation of a scientific process

1. ……………………………………………………………………………………………………………………... . 2. ……………………………………………………………………………………………………………………… 3. ……………………………………………………………………………………………………………………… 4. ……………………………………………………………………………………………………………………… 5. ……………………………………………………………………………………………………………………… 6. ……………………………………………………………………………………………………………………… 7. ……………………………………………………………………………………………………………………… 8. ……………………………………………………………………………………………………………………… 9. …………………………………………………………………………………………………………….. ……….. 10.……………………………………………………………………………………………………………………… III. Translate the following sentences into your native language. 1 Nikolay Semyonov was a Soviet physicist and chemist who, together with Sir Cyril Hinshelwood, was awarded the 1956 Nobel Prize for Chemistry for research into chemical kinetics. Nikolay Semionov a fost un fizician și chimist sovietic, care , împreună cu Sir Cyril Hinshelwood , a primit 1956 Premiul Nobel pentru Chimie pentru cercetarea în cinetica chimic ă . 2 Semyonov had a successful career and became a Professor at the Moscow State University and Director of the Institute of Chemical Physics of the USSR Academy of Sciences. Semionov a avut o carieră de succes și a devenit profesor la Universitatea de Stat din Moscova și director al Institutului de Chimie Fizică al Academiei de Științe a URSS . 3 Semyonov conducted research into the mechanisms of chemical chain reactions. Semionov a efectuat cercetarea în mecanismele de reac ții în lanțul chimic . 4 A chain reaction is a reaction that, once started, continues without further outside influence. O reacție în lanț este o reacție care , odată începută , continuă fără alte influențe din afară . 5 A chain reaction can be of various types, but nuclear chain reactions are the best known. O reacție în lanț poate fi de diferite tipuri , dar reac țiile în lanț nucleare sunt cele mai cunoscute. 6 Semyonov contributed much to the study of chemical chain reactions, the theory of thermal explosions and the burning of gaseous mixtures. Semionov a contribuit mult la studiul reac țiilor chimice în lanț, teoria exploziilor termice și arderea amestecurilor gazoase . 7 Professor Semyonov received many awards and honours from foreign universities and scientific societies. Profesorul Semionov a primit numeroase premii și distincții din universități străine și societăți științifice . Here is a text on atomic and nuclear energy. Read it. Atomic and nuclear power can be very destructive - we need only remember Hiroshima and Nagasaki. This kind of power involves the forces that hold the nucleus of an atom together. These forces contain incredible amounts of energy, and there are two basic ways that nuclear energy can be released from an atom. Now, the first one is nuclear fission – fission means separating. In this process a neutron splits the nucleus of a uranium atom into two smaller fragments. The other method is nuclear fusion, which involves bringing atoms together. Two smaller atoms, usually hydrogen, are brought together to form a larger one such as helium; in fact, this is how the sun produces energy. In both processes, fission and fusion, large amounts of heat and radiation are given off. A fission bomb uses an element like uranium to create a nuclear explosion. Uranium is one of the few materials that can become unstable and split immediately when it absorbs a neutron. As soon as the uranium nucleus captures the neutron, it splits into two lighter atoms and also throws off two or three new neutrons. These then emit gamma radiation. The neutrons that are released during the reaction can, in turn, cause another fission

reaction. This is what is called a chain reaction - it continues by setting off more reactions. In this way, an incredible amount of energy is released when an atom splits. The science behind the process is simple to understand, but it can cause total destruction. In the 1980s, scientists considered the possible effects of a nuclear war and proposed the theory that a 'nuclear winter' could occur. The explosion of many bombs would raise huge clouds of dust and radioactive huge clouds of dust and radioactive material that would travel high into the Earth's atmosphere. These clouds would block out sunlight. Without sunlight, plants would not survive, and this would disrupt the food chain, resulting in the end of all life on the planet. 1. Based on the text, answer the following questions 1 Where is energy contained? Atomic and nuclear power contain incredible amounts of energy. 2 What is nuclear fission? Nuclear fission means separating, and in this process a neutron splits the nucleus of a uranium atom into two smaller fragments. 3 What is used to split an atom? 4 What is nuclear fusion? Nuclear fusion is a process which involves bringing atoms together. 5 When a uranium atom is split into two, what particles are released? Uraniumatom splits into two lighter atoms and also throws off two or three new neutrons, also these then emit gamma radiation. 6 How could a nuclear winter affect life on Earth? A 'nuclear winter' could affect the Earth's atmosphere because of huge clouds of dust and radioactive huge clouds of dust and radioactive, having negatively impact on sunlight,plants ,the food chain, resulting in the end of all life on the planet. 2. Translate the above passage into your native language in written form Putere atomică și nucleară poate fi foarte distructivă - avem nevoie doar amintim Hiroshima și Nagasaki . Acest tip de putere implică forțe care mențin nucleul unui atom împreună . Aceste forțe conțin cantități incredibile de energie , și există două moduri de bază că energia nucleară poate fi eliberată dintr-un atom . Acum , prima este fisiune nucleară - fisiune înseamnă separare . In acest proces un neutron scindează nucleul unui atom de uraniu în două fragmente mai mici . Altă metodă este fuziunea nucleară , care presupune aducerea laolaltă de atomi . Doi atomi mai mici , de obicei hidrogen , sunt aduși împreună pentru a forma unul mai mare , cum ar fi heliu ; de fapt , acesta este modul în care soarele produce energie . In ambele procese , fisiune și fuziune , cantități mari de căldură și de radiații sunt eliminate. O bombă de fisiune utilizează un element similar de uraniu pentru a crea o explozie nucleară . O bombă de fisiune utilizează un element similar de uraniu pentru a crea o explozie nucleară . Uraniu este unul dintre puținele materiale care pot deveni instabil și divizat imediat când absoarbe un neutron . De îndată ce nucleul de uraniu captează neutronul , acesta se imparte in doi atomi mai ușoari și , de asemenea, aruncă doi sau trei noi neutroni . Acestea apoi emit radiații gamma . Neutronii care sunt eliberați în timpul reacției pot , la rândul său , provoca o altă reacție de fisiune . Aceasta este ceea ce se numește o reacție în lanț - se continuă prin compensarea a mai multor reacții . În acest fel , o cantitate incredibila de energie este eliberată atunci când un atom se desparte . Știința din spatele procesul este simplă de înțeles , dar aceasta poate provoca distrugerea totală . In 1980 , oamenii de știință considerau efectele posibile ale unui război nuclear și au propus teoria că ar putea avea loc o " iarna nucleara " . Explozia multor bombe ar ridica nori mari de praf și de materiale radioactive, care se va deplasa în atmosfera inalta a Pământului . Acești nori ar bloca lumina soarelui . Fără a luminii solare , plantele nu ar supraviețui , iar acest lucru ar perturba lanțul alimentar , rezultând un final întregii vieți de pe planetă .

Speaking Skills

(10 minute-activity)

Pair work Discuss with your partner the dangers of nuclear war. Say what you think and find out if your partner agrees or disagrees with you.

1. Talk about: • the main idea behind nuclear energy • nuclear fission • nuclear fusion • the future 3. Remember to: • try to use your own examples • explain yourself clearly • listen to your partner

2. Use these notes to help you The main idea: chemical kinetics and chain reactions Nuclear fusion: what happens? The future: what might happen? Use expressions such as 'I agree / disagree', 'In my opinion'. Invite your partner to speak by asking 'What do you think?' Don't say everything at once remember, it is a discussion not a lecture.

4. Speaking tips

Writing Skills Write a report on the topic:

'Factors affecting chemical reaction rates'

REPORT: Factors affecting reaction rates

Surface area Vocabulary: reaction rate, molecules

By: (Your name)

SECTION 4

Date: (The date) INTRODUCTION Say what the report is about, and briefly list the areas you will discuss. SECTION 1 Concentration Vocabulary: collide SECTION 2 Pressure Vocabulary: compress, force SECTION 3

Reactivity Vocabulary: metals, consumed SECTION 5

Temperature Vocabulary: hot system, activation energy, bounce off SECTION 6

Catalysts Vocabulary: increase rate, minimum energy CONCLUSION

Sum up by giving an outline of the six main areas. Write 200-300 words.

Additional Vocabulary work I. Choose the right word. In each of the sentences below, decide which word in bold is more suitable. 1. During the 1970's and 1980's, it became increasingly evident / visible that companies in the West were uncompetitive. 2. The United Kingdom makes / publishes more books than any other country. 3. There has been a major road accident, involving / including 23 cars and 16 lorries. 4. On the basis of the latest survey, we know that most people have a very negative / bleak view of politicians and their parties. 5. In many parts of the world, people are becoming more worried about the danger of pollution and its effect on the environment / ecology. 6. Education experts from France travelled to Japan to evaluate / judge the secondary school system there. 7. Although it is not very big, the library has an excellent range / variety of books, journals and other resources for study. 8. Increasingly, the design of buildings is being adjusted / modified to allow easier access for disabled people.

9. The lack of extra student accommodation restricted / narrowed the expansion in student numbers which the university was planning. 10. Many students acquire / derive a great deal of enjoyment and satisfaction from their time at university. 11. Although the world is getting warmer slowly, the increase in temperature varies / fluctuates from country to country. 12. Following the bank raid, the police followed / pursued the robbers but were unable to catch them. 13. Assessment on this course includes / consists of coursework (30%) and examinations (70%).

II. Finish the sentence Choose the best ending for each of the sentence extracts below from the list underneath: 1. I like your essay, but I want you to illustrate… 2. What will the result be if in the future we assume… 3. Students may be asked to compare many alternative… 4. The Channel Tunnel between France and England was constructed… 5. Everyone wants to be happy, but we probably all define… 6. Many universities now have language centres to facilitate… 7. Numbers and results are not particularly useful in themselves; we need to interpret… 8. In spite of warnings about cancer, many Westerners equate… 9. Advertisers use a variety of techniques… 10. At first, the police viewed the crimes as random… 11. It may be the case that no solution is possible, given the magnitude… 12. Although computers are becoming increasingly complex,…

13. The investigation was stopped because the witnesses could not identify… a. …theories, from which they have to select the most convincing. b. …happiness in many different ways. c. …that nearly everyone has access to a motor car? d. …the programs they use are becoming much easier to operate. e. …a sun tan with health and youthfulness. f. …the man they had seen commit the robbery. g. …language learning for international students. h. …at a cost of over £8 billion. i. …of this problem. j. …them to understand what they actually mean. k. …events, but realised later that there was a pattern linking them. l. …to persuade consumers to buy products and services. m. …your points by providing some supporting examples.

III. Adjectives to nouns NB: A lot of adjectives can be changed to nouns by the addition of a suffix (e.g., brave - bravery, equal - equality,, etc), or by changing other features of the word (e.g., proud - pride, sympathetic - sympathy, etc). Some nouns need a prefix and a suffix, depending on how they are being used (e.g., equal = equality or inequality)

Look at these sentences, and decide if the nouns in bold are correct or incorrect (the key adjectives are in brackets at the end of each sentence). Look at the meaning of the whole sentence before you decide, and don't forget to check the spelling. 1. I'm not sure you're old enough to be given such a responsibility. (responsible) 2. Although there are several differents between British and American English, there are also many similarity. (different / similar) 3. It was a terrible lesson, the hotness in the room was unbearable, we were almost falling asleep with boredom, and our stomachs were rumbling with hungryness. (hot / bored / hungry) 4. I asked her if she was telling the trueth. (true) 5. The check-in staff said that the flight was late and apologised for the convenience, although they didn't show much sympathetically. (convenient / sympathetic) 6. They almost died of thirstiness before they were rescued. (thirsty) 7. Your calculations are wrong; there are several accuracies. (accurate) 8. We had to measure the length, the wideth and the deepth of the swimming pool, and then measure the hight of the diving board. (long / wide / deep / high) 9. She experienced a lot of happyness and lonelyness in her lifetime; her parents died when she was still in her youth, her first husband left her, and her only child ran away from home. (happy / lonely / young) 10. He lacked confidence in his ableness, and seemed unaware of his own intelligence. (confident / able / intelligent) 11. There's a strong probableness, perhaps even a certainty, that he's going to get a grade A in the exam. (probable / certain)