Здравствуйте, уважаемые студенты. Напоминаю вам о занятиях он лайн с пн. по пт. -
https://join.skype.com/e55vdytqxevA
1);Grammar - pick out all the sentences which have infinitive from the text -
https://www.bbc.co.uk/learningenglish/english/features/6-minute-english/ep-200312
2) Speaking - make up a presentation of the main idea from the link above - 10-15 sentences
3) Text Book -
https://www.ck12.org/book/ck-12-chemistry-intermediate/section/18.0/
https://www.ck12.org/book/ck-12-chemistry-intermediate/section/18.1/
https://join.skype.com/e55vdytqxevA
1);Grammar - pick out all the sentences which have infinitive from the text -
https://www.bbc.co.uk/learningenglish/english/features/6-minute-english/ep-200312
2) Speaking - make up a presentation of the main idea from the link above - 10-15 sentences
3) Text Book -
https://www.ck12.org/book/ck-12-chemistry-intermediate/section/18.0/
https://www.ck12.org/book/ck-12-chemistry-intermediate/section/18.1/
Text 18.1
ОтветитьУдалитьCollision Theory
The behavior of the reactant atoms, molecules, or ions is responsible for the rates of a given chemical reaction. Collision theory is a set of principles based around the idea that reactant particles form products when they collide with one another, but only when those collisions have enough kinetic energy and the correct orientation to cause a reaction. Particles that lack the necessary kinetic energy may collide, but the particles will simply bounce off one another unchanged. The figure below illustrates the difference. In the first collision, the particles bounce off one another, and no rearrangement of atoms has occurred. The second collision occurs with greater kinetic energy, and so the bond between the two red atoms breaks. One red atom bonds with the other molecule as one product, while the single red atom is the other product. The first collision is called an ineffective collision, while the second collision is called an effective collision.
Supplying reactant particles with energy causes the bonds between the atoms to vibrate with a greater frequency. This increase in vibrational energy makes a chemical bond more likely to break and a chemical reaction more likely to occur when those particles collide with other particles. Additionally, more energetic particles have more forceful collisions, which also increases the likelihood that a rearrangement of atoms will take place. The activation energy for a reaction is the minimum energy that colliding particles must have in order to undergo a reaction. Some reactions occur readily at room temperature because most of the reacting particles already have the requisite activation energy at that temperature. Other reactions only occur when heated because the particles do not have enough energy to react unless more is provided by an external source of heat.
Теория Столкновений
Поведение атомов, молекул или ионов реагента отвечает за скорость протекания данной химической реакции. Теория столкновений - это набор принципов, основанных на идее, что частицы реагента образуют продукты, когда они сталкиваются друг с другом, но только тогда, когда эти столкновения имеют достаточную кинетическую энергию и правильную ориентацию, чтобы вызвать реакцию. Частицы, которым не хватает необходимой кинетической энергии, могут сталкиваться, но частицы будут просто отскакивать друг от друга без изменений. Рисунок ниже иллюстрирует эту разницу. При первом столкновении частицы отскакивают друг от друга, и никакой перестройки атомов не происходит. Второе столкновение происходит с большей кинетической энергией, и поэтому связь между двумя красными атомами разрывается. Один красный атом связывается с другой молекулой как один продукт, в то время как другой красный атом является другим продуктом. Первое столкновение называется неэффективным столкновением, а второе столкновение - эффективным .
Подача энергии частицам реагента заставляет связи между атомами вибрировать с большей частотой. Это увеличение вибрационной энергии делает химическую связь более вероятной для разрыва, а химическую реакцию - более вероятной, когда эти частицы сталкиваются с другими частицами. Кроме того, более энергичные частицы имеют более сильные столкновения, что также увеличивает вероятность того, что произойдет перестройка атомов. Энергия активации для реакции - это минимальная энергия, которую должны иметь сталкивающиеся частицы, чтобы провести реакцию. Некоторые реакции легко протекают при комнатной температуре, поскольку большинство реагирующих частиц уже обладают необходимой энергией активации при этой температуре. Другие реакции происходят только при нагревании, потому что частицы не обладают достаточной энергией для реакции, если только внешний источник тепла не дает больше энергии.
Test 18.1
ОтветитьУдалить1. A reaction rate is the change in concentration of a reactant or product with time(molarity per second).
2. Reactant particles form products when they collide with one another, but only when those collisions have enough kinetic energy and the correct orientation to cause a reaction.
3. Enough kinetic energy and the correct orientation
4. The activation energy for a reaction is illustrated in the potential energy diagram by the height of the hill between the reactants and the products. For this reason, the activation energy of a reaction is sometimes referred to as the activation energy barrier. Reacting particles must have enough energy so that when they collide, they can overcome this barrier
5. An activated complex is an unstable arrangement of atoms that exists momentarily at the peak of the activation energy barrier. Because of its high energy, the activated complex exists only for an extremely short period of time (about 10−13 s).
6. Increasing the concentration of one or more of the reacting substances generally increases the reaction rate.
An increase in the pressure of a gas is also an increase in the concentration of the gas.
An increase in the surface area of a reactant increases the rate of a reaction.
7.A catalyst is a substance that increases the rate of a chemical reaction without being used up in the reaction. It accomplishes this task by providing an alternate reaction pathway that has a lower activation energy barrier.
8. 0,0094 M/s
9. d
10.a)20 kJ/mol
b)50 kJ/mol
c)30 kJ/mol
d)100 kJ/mol
e)80 kJ/mol
f) endothermic
g) energy of the activated complex(d)
the activation energy for the reaction(e )
Grammer
ОтветитьУдалитьSam and Neil discuss our future and whether we need to start panicking but not before they teach you some useful vocabulary.
Listen to the programme to find out the answer.
We’re far too clever to die out, aren’t we?
Instead, they could destroy civilisation as we know it, leaving pockets of survivors to struggle on in a post-apocalyptic world.
And there’s not much we can do to stop disasters like that!
True, Sam, but what about individuals who actively work to bring about the end of the world - like apocalyptic terrorists, rampage shooters and fundamentalist cults like those who organised the poisonous gas attack on the Tokyo subway.
Those are people who want to end human life on Earth and bring about Doomsday - another word for the final, apocalyptic day of the world’s existence.
Nuclear Armageddon was only averted by the actions of one clear-thinking Russian general who decided not to push the red button.
Well, Neil, all this doomongering has made me want to just give it all up and live on a desert island!
So, to recap, in this programme we’ve been discussing Doomsday – the final day of life on Earth and other existential threats - dangers threatening the survival of humans on the planet.
We looked back throughout the historical record - all recorded human history, to see examples of threats which have wiped out, or killed millions of people in the past, including wars and plagues which spread epidemic diseases between populations.
1. The rate for the reaction is positive, and the units are molarity per second or M/s.
ОтветитьУдалить2. Reactant particles form products when they collide with one another, but only when those collisions have enough kinetic energy and the correct orientation to cause a reaction.
3. They must have enough kinetic energy and the correct orientation to cause a reaction.
4. The activation energy for a reaction is illustrated in the potential energy diagram by the height of the hill between the reactants and the products. For this reason, the activation energy of a reaction is sometimes referred to as the activation energy barrier. Reacting particles must have enough energy so that when they collide, they can overcome this barrier.
5. An activated complex is an unstable arrangement of atoms that exists momentarily at the peak of the activation energy barrier. Because of its high energy, the activated complex exists only for an extremely short period of time (about 10^−13 s).
6. Increasing the concentration of one or more of the reacting substances generally increases the reaction rate. When the pressure of a gas is increased, its particles are forced closer together, decreasing the amount of empty space between them. Therefore, an increase in the pressure of a gas is also an increase in the concentration of the gas. For gaseous reactions, an increase in pressure increases the rate of reaction for the same reasons as described above for an increase in concentration. An increase in the surface area of a reactant increases the rate of a reaction.
7. Catalyst is a substance that increases the rate of a chemical reaction without being used up in the reaction. The important point is that the use of a catalyst lowers the overall activation energy of the reaction.
8. 0,0094 M/s
9. d
10. a. 20 kJ/mol b. 50 kJ/mol c. 30 kJ/mol d. 100 kJ/mol e. 80 kJ/mol f. endothermic g. the potential energy of the activated complex –d, the activation energy for the reaction - e
Text 18.1
ОтветитьУдалитьChemical reactions vary widely in the speeds with which they occur. Some reactions occur very quickly. If a lighted match is brought in contact with lighter fluid or another flammable liquid, it erupts into flame instantly and burns fast. Other reactions occur very slowly. A container of milk in the refrigerator will be good to drink for weeks before it begins to turn sour. Millions of years were required for dead plants under Earth’s surface to accumulate and eventually turn into fossil fuels such as coal and oil.
Chemists need to be concerned with the rates at which chemical reactions occur. Rate is another word for speed. If a sprinter takes 11.0 seconds to run a 100 meter dash, his rate or speed is given by the distance traveled divided by the time.
The sprinter’s average running rate for the race is 9.09 m/s. We say that it is his average rate because he did not run at that speed for the entire race. At the very beginning of the race, while coming from a standstill, his rate must be slower until he is able to get up to his top speed. His top speed must then be greater than 9.09 m/s so that taken over the entire race, the average ends up at 9.09 m/s.
Химические реакции сильно различаются по скорости, с которой они происходят. Некоторые реакции происходят очень быстро. Если зажженная спичка соприкасается с керосином или другой горючей жидкостью, она мгновенно вспыхивает и быстро сгорает. Другие реакции происходят крайне медленно. Молоко хранящееся в холодильнике можно употреблять в течение нескольких недель, прежде чем он скиснет. Потребовались миллионы лет, чтобы мертвые растения под поверхностью Земли накапливались и в конечном итоге превращались в ископаемые виды топлива, такие как уголь и нефть.
Химики должны знать скорость, с которой происходят химические реакции. Расход это еще одно слово для обозначения скорости. Если спринтеру требуется 11,0 секунд, чтобы пробежать 100 метров, его скорость определяется пройденным расстоянием, деленным на время.
Средняя скорость бега спринтера составляет 9,09 м / с. Мы говорим, что это его средняя скорость, потому что он не бегал на этой скорости всю гонку. В самом начале гонки, когда он выходит из состояния покоя, его скорость ниже, чем максимальная. Его максимальная скорость должна быть больше 9,09 м / с, чтобы в среднем достичь 9,09 м/с.
Test 18.1
Удалить№ 1. A reaction rate is usually expressed in mols per second.
№ 2. Those collisions form product only when they have enough kinetic energy and the correct orientation to cause a reaction.
№ 3. Enough kinetic energy and the correct orientation
№ 4. The activation energy for a reaction is illustrated in the potential energy diagram by the height of the hill between the reactants and the products. For this reason, the activation energy of a reaction is sometimes referred to as the activation energy barrier. Reacting particles must have enough energy so that when they collide, they can overcome this barrier
№ 5. An activated complex is an unstable arrangement of atoms that exists momentarily at the peak of the activation energy barrier. Because of its high energy, the activated complex exists only for an extremely short period of time (about 10−13 s).
№ 6. Increasing the concentration of one or more of the reacting substances generally increases the reaction rate.
An increase in the pressure of a gas is also an increase in the concentration of the gas.
An increase in the surface area of a reactant increases the rate of a reaction.
№ 7. A catalyst is a substance that increases the rate of a chemical reaction without being used up in the reaction. It accomplishes this task by providing an alternate reaction pathway that has a lower activation energy barrier.
№ 8. 0,0094 M/s
№ 9. d
№ 10.a. 20 kJ/mol
b. 50 kJ/mol
c. 30 kJ/mol
d. 100 kJ/mol
e. 80 kJ/mol
f. endothermic
Grammer
ОтветитьУдалитьSam and Neil discuss our future and whether we need to start panicking but not before they teach you some useful vocabulary.
Listen to the programme to find out the answer.
We’re far too clever to die out, aren’t we?
Instead, they could destroy civilisation as we know it, leaving pockets of survivors to struggle on in a post-apocalyptic world.
And there’s not much we can do to stop disasters like that!
True, Sam, but what about individuals who actively work to bring about the end of the world - like apocalyptic terrorists, rampage shooters and fundamentalist cults like those who organised the poisonous gas attack on the Tokyo subway.
Those are people who want to end human life on Earth and bring about Doomsday - another word for the final, apocalyptic day of the world’s existence.
Nuclear Armageddon was only averted by the actions of one clear-thinking Russian general who decided not to push the red button.
Well, Neil, all this doomongering has made me want to just give it all up and live on a desert island!
So, to recap, in this programme we’ve been discussing Doomsday – the final day of life on Earth and other existential threats - dangers threatening the survival of humans on the planet.
We looked back throughout the historical record - all recorded human history, to see examples of threats which have wiped out, or killed millions of people in the past, including wars and plagues which spread epidemic diseases between populations.
Диаграммы Потенциальной Энергии
Энергетические изменения, происходящие во время химической реакции, могут быть показаны на диаграмме, называемой диаграммой потенциальной энергии, иногда называемой кривой хода реакции. Диаграмма потенциальной энергии показывает изменение потенциальной энергии системы по мере превращения реагентов в продукты. На рисунке ниже (Рис.ниже) показаны основные диаграммы потенциальной энергии для эндотермической (слева) и экзотермической (справа) реакций. Напомним, что изменение энтальпии (ΔH) положительно для эндотермической реакции и отрицательно для экзотермической реакции. Это можно увидеть на диаграммах потенциальной энергии. Общая потенциальная энергия системы увеличивается для эндотермической реакции, поскольку система поглощает энергию из окружающей среды. Общая потенциальная энергия системы уменьшается для экзотермической реакции, поскольку система высвобождает энергию в окружающую среду.
Диаграмма потенциальной энергии показывает полную потенциальную энергию реагирующей системы по мере протекания реакции. (слева) в