КАТЕГОРИИ:
АстрономияБиологияГеографияДругие языкиДругоеИнформатикаИсторияКультураЛитератураЛогикаМатематикаМедицинаМеханикаОбразованиеОхрана трудаПедагогикаПолитикаПравоПсихологияРиторикаСоциологияСпортСтроительствоТехнологияФизикаФилософияФинансыХимияЧерчениеЭкологияЭкономикаЭлектроника
Reading Comprehension. Chemical Kinetics Exercises
Chemical Kinetics Exercises
Phonetics
I. Find the words in the word square and match them with the transcription
| m | a | g | n | e | s | i | u | m | e | p | a |
| m | o | l | e | c | u | l | e | n | o | r | l |
| c | r | o | s | u | b | l | k | w | u | e | i |
| a | h | c | o | n | s | u | m | e | d | c | q |
| t | o | e | c | a | t | a | l | y | s | t | u |
| e | c | o | m | t | a | s | p | z | a | c | i |
| v | c | s | a | i | n | u | r | i | x | o | d |
| s | u | f | f | i | c | i | e | n | t | l | e |
| o | r | p | t | g | e | a | b | c | d | l | m |
| h | y | d | r | o | c | h | l | o | r | i | c |
| m | o | r | e | e | t | q | n | p | i | s | t |
| s | i | r | a | l | s | o | v | w | x | i | m |
| a | o | k | z | v | m | s | g | j | z | o | l |
| h | p | u | t | a | l | m | u | h | s | n | b |
| f | g | d | c | o | p | p | e | r | b | y | c |
| j | c | u | e | t | x | i | d | a | e | s | k |
[kən'sjuːmd] ['kætəlɪst] [sə'fɪʃənt]
['haɪdrəuklɔːrik] [mæg'niːzɪəm] ['kemɪkəl]
[ə'kɜː] ['preʃə] [kə'lɪʒən] ['sʌbstəns] ['kɔpə]
[zɪŋk] ['lɪkwɪd] ['mɔlɪkjuːl]
Reading Comprehension
II. Answer the questions:
1. What does chemical kinetics study?
It’s the study of rates of chemical reactions.
2. Do all the reactions in the world have the same rate? Give the examples.
Not all the reactions in the world have the same rate. For example, it can take years for wood to rot, while the lighting of a match takes just an instant.
3. What are the factors controlling the rates of chemical reactions?
These factors are concentration, pressure, surface area, the nature of reacting substances, temperature and catalyst.
4. Must molecules bounce off to react?
No they mustn’t. Molecules must collide to react.
5. Describe the changes in the reaction if pressure decreases.
Reaction rate decreases with pressure.
6. When does the surface area affect the rate of the reaction?
The surface area will affect the rate of the reaction, if a chemical reaction takes place at a boundary between two states.
7. Are all metals equally reactive? Give the examples.
No they aren’t. For example, if the metal magnesium, zinc and copper are dropped into hydrochloric acid in separate test tubes, three very different results are obtained. Magnesium is more reactive than zinc and the last is more reactive than copper.
8. What is activation energy? What does it depend on?
It’s the minimum amount of energy that the reacting molecules must have to react. Higher temperature gives molecules the energy to collide forcefully.
9. Which substance do we call a catalyst?
A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the reaction.
10. Do all substances have equal activation energy?
No, substances have different activation energy.
11. Complete the table with the factors controlling the reaction rates and their effects:
| Factor | Effect |
| Concentration | Increasing/decreasing the concentration increases/decreases the reaction rate |
| Pressure | Reaction rate increases with pressure |
| Surface area | Increasing the surface area leads to higher reaction rate |
| temperature | 1)Molecules move faster in a hot system than in a cold one à reaction rate increases 2)Higher temperatures give molecules the energy to collide forcefully à reaction rate increases |
| catalysts | Increases the rate of the reaction by reducing the activation energy |
Дата добавления: 2015-09-13; просмотров: 63; Мы поможем в написании вашей работы!; Нарушение авторских прав |
| <== предыдущая лекция | | | следующая лекция ==> |
| | |