Tài liệu tập huấn giảng viên dạy chuyên ngành Hóa học bằng tiếng Anh

TÀI LIỆU TẬP HUẤN GIẢNG VIÊN DẠY CHUYÊN NGÀNH BẰNG TIẾNG ANH KHOA: HÓA HỌC 1 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh MỤC LỤC BÀI 1: KINH NGHIỆM XÂY DỰNG CHƯƠNG TRÌNH MÔN HÓA HỌC BẰNG TIẾNG ANH.......................................................................................................... 2 BÀI 2: MATTER AND CLASSIFICATION OF MATTER .................................. 4 BÀI 3: ELEMENTS AND PERIODIC TABLE ...................................................... 12 BÀI 4: THE ALKALI METALS .................................................................................. 23 BÀI 5: ANKANES ........................................................................................................... 32 2 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh BÀI 1: KINH NGHIỆM XÂY DỰNG CHƯƠNG TRÌNH MÔN HÓA HỌC BẰNG TIẾNG ANH 1.1 Cơ sở lý thuyết Chương trình chi tiết giáo dục đại học ngành Sư phạm Hóa học dạy bằng tiếng Anh được xây dựng trên cơ sở chương trình khung giáo dục đại học ngành Sư phạm Hóa học trình độ đại học, ban hành theo quyết định số 2682/QĐ – ĐHSP HN, ngày 21 tháng 9 năm 2009 của Hiệu trưởng trường Đại học Sư phạm Hà Nội. Chương trình chi tiết giáo dục đại học ngành Sư phạm Hóa học bằng tiếng Anh được xây dựng trên cơ sở kế thừa bề dày truyền thống gần 64 năm đào tạo giáo viên của khoa Hóa học, trường Đại học Sư phạm Hà Nội, kết hợp với nguyên tắc đảm bảo tính hiện đại, tính hiệu quả, tính hệ thống và tính phát triển, tính thực tiễn và mềm dẻo. Trên cơ sở đó, chương trình phát triển phù hợp với các yêu cầu và đòi hỏi ngày càng cao của đời sống xã hội, về sự hòa nhập quốc tế và khu vực, thực hiện tốt hơn nhiệm vụ đào tạo giáo viên giảng dạy Hóa học ở các trường THPT. Chương trình đào tạo nhằm đào tạo đội ngũ giáo viên có năng lực chuyên môn, nghiệp vụ chất lượng cao, có khả năng giảng dạy Hóa học ở phố thông bằng tiếng Anh, thể hiện được đổi mới về nội dung và phương pháp đào tạo theo hướng cập nhật với quốc tế, đồng thời phù hợp với điều kiện của Việt Nam. Chương trình chi tiết giáo dục đại học ngành Sư phạm Hóa học dạy bằng tiếng Anh được xây dựng đáp ứng yêu cầu của chuẩn đầu ra là đào tạo cán bộ có đủ năng lực làm giáo viên dạy học Hóa học cấp học trung học cơ sở, trung học phổ thông bằng tiếng Anh. Có ý chí vươn lên và có đủ khả năng tiếp tục học tập để trở thành giáo viên các trường trung học chuyên nghiệp, trường cao đẳng và đại học; cán bộ nghiên cứu tại các trung tâm nghiên cứu khoa học, viện nghiên cứu, cơ sở sản xuất thuộc ngành Hóa học, Môi trường, cơ sở sản xuất kinh doanh có liên quan đến lĩnh vực Hóa học. Sinh viên tốt nghiệp ngành Sư phạm Hóa học có đủ khả năng tiếp tục học tập và nghiên cứu chuyên môn ở trình độ thạc sỹ và tiến sỹ hóa học, cũng như có đủ khả năng để có thể xin được các học bổng của nước ngoài. 3 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh 1.2 Tiến trình xây dựng: - Xây dựng chương trình đào tạo cử nhân sư phạm Hóa dạy bằng tiếng Anh. - Xây dựng khung trương trình chi tiết - Xây dựng bài giảng bằng tiếng Anh - Tiến hành dạy mẫu, rút kinh nghiệm - Chỉnh sửa tài liệu - Nghiệm thu chương trình và tài liệu giảng dạy Hóa học bằng tiếng Anh - Tiến hành dạy cho sinh viên khoa Hóa học - Hàng năm có tổ chức rút kinh nghiệm, chỉnh sửa chương trình, đề cương chi tiết cũng như bài giảng cho hoàn thiện. 4 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh BÀI 2: MATTER AND CLASSIFICATION OF MATTER Vocabulary Matter Pure substance Element Compound Mixture Homogeneous Heterogeneous Composition Component Proportion Uniform Atom Molecule Combination Properties Dictionary definitions of chemistry usually include the terms matter, composition, and properties, as in the statement that “chemistry is the science that deals with the composition and properties of various forms of matter”. Matter is anything that occupies the space and displays a property known as mass. Every human being is an object of matter. We all occupy space, and we describe our mass though a related property, our weight. All the objects that we see around us are objects of matter. The gases of the atmosphere, even though they are invisible, are example of matter; they occupy space and possess mass. Composition refers to the parts of components of a sample of matter and their relative proportions. Ordinary water is comprised of two simpler substances – hydrogen and oxygen – present in certain fixed proportions. Properties are those qualities or attributes that can be used to distinguish one sample of matter form others. Matter is classified into two broad categories, namely, pure substances and mixtures. A pure substance can be either an element or a compound. The composition and properties of an element or compound are uniform 5 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh throughout a given sample and from one sample to another. A chemical element is a substance comprised of a single type of atom. The elements are the building blocks of our nature. An element is either discovered in nature or synthesized in the laboratory in pure form that cannot be separated into simpler substances by chemical methods. Currently, there are about 118 elements discovered; some are found to be unique; no two elements are alike. Elements are made up of tiny particles called atoms. Atoms are the smallest particles of an element that have the chemical properties of that element. Each element contains only one type of atoms. The atoms of one element are not the same as the atoms of another element. Most of the elements exist as monoatomic forms, which means that the smallest individual complete parts of these samples of pure elements are single atoms. Seven of the known elements are called diatomic elements, because they are found in nature in their elemental form as two-atom molecules. The seven diatomic elements are chlorine (Cl2), fluorine (F2), bromine (Br2), iodine (I2), hydrogen (H2), oxygen (O2), and nitrogen (N2). A compound is the substance formed by the chemical union of two or more element. The number of compounds now known is in the millions. In some cases we can isolate a molecule of a compound. A molecule is the smallest entity having the same proportions of the constituent atoms as does the compound as a whole. A molecule of water consists of three atoms – two hydrogen atoms joined to a single oxygen atom. Components of the compounds are in a definite ratio, which is fixed by the nature. We cannot change this ratio, no matter who does it. For example, water is made up of one part oxygen and two parts hydrogen. This ratio is fixed by the nature and we cannot alter this. Compounds are formed by chemical reactions, where the individual elements lose their individual properties and take on the new properties of the compound that is formed. Compounds can be separated into elements using chemical methods but not the physical methods. A mixture is a physical combination of two or more substances where the substances retain their original identity. Some examples are air, milk, various fruit drinks. The most important aspect of the mixture is that it has no definite or constant composition, Mixtures can be separated into pure 6 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh substances by physical methods. Mixture is further classified as either homogeneous or heterogeneous based upon its uniformity. A homogeneous mixture is a solution that has a uniform consistency throughout, for example, a salt solution after dissolving and mixing it thoroughly. Not only that but also the individual components cannot be identified. A heterogeneous mixture does not have uniform composition like homogeneous mixture where the individual components can be identified, for example, a mixture of sand and salt. The scheme that classified matter into elements, compounds and mixtures is summarized in figure 1. Figure 1. A classification scheme for matter I. Comprehension questions 1. What is chemistry?  Chemistry is the science that deals with the composition and properties of various forms of matter. 2. Why is water an object of matter?  Because water occupies space and has mass. 3. What is water made up of?  Water is made up of hydrogen and oxygen. 4. What is the difference between an element and a compound? 7 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh An element is a substance composed of a single type of atom while a compound is the substance formed by two or more element chemically combined. 5. What is a molecule defined as?  A molecule is the smallest entity having the same proportions of the constituent atoms as does the compound as a whole. 6. What is the difference between homogeneous and heterogeneous mixtures?  A homogeneous mixture has a uniform consistency throughout while a heterogeneous mixture does not have uniform composition. 7. Which kind of matter has uniform composition?  Pure substance has uniform composition. 8. What are the building blocks of the elements?  The building blocks of the elements are the atoms. 9. Why is chlorine called a diatomic element?  Because chlorine contains two atoms in its molecules. 10. Which kind of matter can be separated by physical methods?  Mixture can be separated into substances by physical methods. II. True (T) or false (F) or not mentioned (N) statements No T/F/N Statements 1. A substance is a type of matter that has a consistent composition. 2. Elements are substances that are made up of two or more elements chemically combined. 3. Whereas a compound is made from the chemical combination of two or more substances, a mixture is made from two or more substances that are physically combined. 4. Heterogeneous mixtures are mixtures that have a consistent, or uniform composition throughout the entire sample. 5. Unlike in the example of compounds, the substances that make up a 8 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh mixture do not lose their individual properties. 6. The individual substances in a mixture do not lose their original properties, and the substances in a mixture can be separated by physical means. 7. When the compound is formed, altogether a new substance is formed and the properties of which are similar to its constituent elements. 8. All mixtures have a variable composition, it means that the substances that are found in the mixture can be mixed in with varying proportion or concentrations. 9. Chemical reactions can break more complex substances down into elements, but elements can only be broken down further by nuclear reactions. 10. Oxygen is a substance because it has a consistent composition and it is an element because it is only made up of one type of atom. III. Translation Translation 1 1. Các nguyên tố có thể được phân loại thành hai nhóm chính – kim loại và phi kim. Elements can be classified into two major groups – metals and non- metals. 2. Phân tử là nhóm gồm hai hay nhiều hơn các nguyên tử mà liên kết một cách hóa học với nhau. A molecule is a group of two or more atoms that are chemically combined. 3. Hợp chất được tạo bởi các nguyên tố khác nhau liên kết một cách hóa học với nhau theo một tỉ lệ xác định. A compound is made up of different elements chemically combined in a fixed ratio. 9 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh 4. Các ion tích điện dương được hình thành khi một nguyên tử mất đi electron. A positively charged ion is formed when an atom loses electrons. 5. Nhiệt có thể được sử dụng để phá vỡ hợp chất thành các hợp chất đơn giản hơn hoặc là các nguyên tố. Heat can be used to break down compounds into elements or simpler compounds. 6. Các thành phần của hỗn hợp có thể trộn lẫn với nhau theo một tỷ lệ bất kỳ. The components of a mixture can be mixed in any proportion. 7. Một số chất nguyên chất, giống như bạc, chỉ chứa một loại chất. Some substances, like silver, contain only one kind of matter. 8. Hỗn hợp đồng thể của chất tan và dung môi được gọi là dung dịch. A homogeneous mixture of solute and solvent are called solutions. 9. Các dạng đơn giản của chất mà không thể phân hủy thành các chất đơn giản hơn được gọi là các nguyên tố. Simple forms of matter which cannot be decomposed into further simple substances are called elements. 10. Hợp chất của sắt và lưu huỳnh là sắt sunfua. A compound of iron and sulfur is iron sulf ide. Translation 2 1. Petroleum is a very complex mixture that we extract from the Earth. Xăng dầu là một hỗn hợp rất phức tạp mà chúng ta có thể chiết xuất từ Trái Đất. 2. Colloids are the heterogeneous mixture of two or more components with the size of the particle is 1nm to 100nm. Các chất keo là hỗn hợp dị thể của hai hay nhiều các thành tố với kích thước hạt từ 1nm đến 100nm. 3. A mixture of two components that appears in a single phase is called a homogeneous mixture. Một hỗn hợp của hai thành tố tồn tại ở một pha được gọi là hỗn hợp đồng thể. 10 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh 4. The amount of a solute present in a unit volume of the solution is called concentration of the solution. Lượng chất tan tồn tại trong một đơn vị thể tích của dung dịch được gọi là nồng độ của dung dịch. 5. Chalk contains calcium, carbon, and oxygen in the proportion of one atom each of calcium and carbon to three atoms of oxygen. Phấn chứa canxi, cacbon và oxi theo tỉ lệ một nguyên tử canxi và cacbon với ba nguyên tử oxi. 6. Alloys are usually made to improve on the properties of the elements that make them up. Cách hợp kim thường được tạo ra với mục đích làm tăng các tính chất của các nguyên tố tạo nên chúng. 7. An important characteristic of a compound is that it has a chemical formula, which describes the ratio in which the atoms of each element in the compound occur. Một đặc tính quan trọng của hợp chất là chúng có công thức hóa học mô tả tỉ lệ các nguyên tử của mỗi nguyên tố tham gia trong hợp chất. 8. Elemental symbols are the abbreviated notations for elements consisting of one or two letters. Kí hiệu nguyên tố là dạng kí hiệu viết tắt của các nguyên tố bao gồm một hoặc hai chữ cái. 9. The weight is a measure of the gravitational force exerted on an object. Trọng lượng được đo bằng lực trọng trường tác dụng lên vật. 10. A phase is a region of matter that possesses uniform intensive properties throughout its volume. Pha là vùng của chất có các tính chất cường độ đồng nhất trong toàn bộ thể tích của chúng. IV. Further reading The states of matter Matter can exist in three different states, solid, liquid, and gas, based on the way the atoms and molecules are arranged inside them. These three states are known as three different states of matter. 11 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh In solids, atoms or molecules are tightly bound to one another thereby creating a rigid nature. Each atom or molecule is caged by its neighbors creating non-mobility, although they might vibrate around the equilibrium position. Here attractive forces are very strong. Consequently, solids have definite shapes and volumes. Some examples of solids are diamond, metals, and ice. In liquids, the atoms or molecules are not as tightly bound as in solids and due to that they have some freedom to move around. They still experience attractive forces but not as strong as solids. In addition, they also begin to experience some repulsive forces. Thus, liquids have definite volume but not definite shape- they assume the shape of the container. Due to their flexibility, the liquids can be poured from one container to another. Some common examples are water, gasoline, and alcohol at room temperature. In gases, the atoms or molecules are far apart due to they are not bounded at all, meaning, they do not have any attractive forces but only repulsive forces. Due to that they can occupy a large volume. They do not have their own shape or volume, but assume the shape and the volume of the container. Some common examples are oxygen, hydrogen, and helium at room temperature. 12 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh BÀI 3: ELEMENTS AND PERIODIC TABLE Vocabulary Oxidation number Principle Atom Quantum number Atomic orbitals Relative pronouns Azimuthal quantum number Rule Electron configuration Wave function Electron state Solvent Magnetic quantum number Confusion Metallic character Determine I. Reading comprehension Periodic table The idea of arranging the elements into a periodic table had been considered by many chemists, but either data to support the idea were insufficient or the classification schemes were incomplete. Mendeleev and Meyer organized the elements in order of atomic weight and then identified groups of elements with similar properties. By arranging these groups in rows and columns, and by considering similarities in chemical behavior as well as atomic weight, Mendeleev found vacancies in the table and was able to predict the properties of several elements—gallium, scandium, germanium, and polonium—that had not yet been discovered. When his predictions proved accurate, the concept of a periodic table was quickly accepted. The discovery of additional elements not known in Mendeleev’s time and the synthesis of heavy elements have led to the modern periodic table, shown inside the front cover of this text. In the modern periodic table, a horizontal row of elements is called a period and a vertical column is a group. The traditional designations 13 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh of groups in the United States differ from those used in Europe. The International Union of Pure and Applied Chemistry (IUPAC) has recommended that the groups be numbered 1 through 18. In this text, we will use primarily the IUPAC group numbers. Some sections of the periodic table have traditional names, as shown in Figure 1. Starting from hydrogen, over 100 elements are constituted as electrons are successively accommodated into 1s, 2s, 2p, 3s, 3p, 4s, and 3d orbitals one by one from lower to higher energy levels. When elements with similar properties are arranged in columns, the periodic table of the elements is constructed. The modern periodic table of the elements is based on one published by D. I. Mendeleev in 1892, and a variety of tables have since been devised. The long periodic table recommended by IUPAC is the current standard, and it has the group numbers arranged from Group 1 alkali metals through group 18 rare gas elements. Based on the composition of electron orbitals, hydrogen, helium and Group 1 elements are classified as s-block elements, Group 13 through Group 18 elements p-block elements, Group 3 through Group 12 elements d-block elements, and lanthanoid and actinoid elements f-block elements. (Fig. 1). s-Block, p-block, and Group 12 elements are called main group elements and d-block elements other than Group 12 and f-block elements are called transition elements. Incidentally, periodic tables that denote the groups of s-block and p-block elements with Roman numerals (I, II, ..., VIII) are still used, but they will be unified into the IUPAC system in the near future. Since inorganic chemistry covers the chemistry of all the elements, it is important to understand the features of each element though reference to the periodic table. 14 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh Figure 1 Periodic table I.1. Question: 1. How did Mendeleev and Meyer organize the elements? Mendeleev and Meyer organized the elements in order of atomic weight and then identified groups of elements with similar properties. 2. What is the best advantage of Mendeleev’s organization of element? Mendeleev found vacancies in the table and was able to predict the properties of several elements—gallium, scandium, germanium, and polonium—that had not yet been discovered 3. What are names of horizontal row and vertical column of elements called in a modern periodic table? The horizontal row of elements is called a period and a vertical column is a group. 4. How electrons are filled up in the first 100 elements in the periodic table? s-block d-block f-block p-block 15 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh These electrons are successively accommodated into 1s, 2s, 2p, 3s, 3p, 4s, and 3d orbitals one by one from lower to higher energy levels 5. How does IUPAC recommend for group numbering? It has recommended that the groups be numbered 1 through 18. 6. What is general name of elements if the Group 18? It is the rare gas. 7. Which elements are classified as the s-block elements? Hydrogen, helium and Group 1 elements 8. What is another name of d-block elements? They are called transition elements. 9. What are main group elements? s-Block, p-block, and Group 12 elements are called main group elements. 10. What is the necessary ideal to learn about periodic table? The periodic table helps us to predict the features of each element. I.2. True (T), false (F) or doesn’t say (DS) 11  Arrangement of elements is based on considering similarities in chemical behavior. 12  IUPAC has suggested using Roman number for labeling groups. 13  All elements are constructed by electrons that accommodate 1s, 2s, 2p, 3s, 3p, 4s, and 3d orbitals. 14  There is no change in chemical properties of elements following a period. 15  The discovery of additional elements not known in Mendeleev’s time. 16 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh 16  f-Block elements are only called transition elements. 17  A variety of tables have since been invented at the same time with D. I. Mendeleev’s periodic table. 18  Mayer had recommended that the groups be numbered 1 through 18. 19  The d-block corresponds to the transition metals. 20  Blocks are sometimes called families. I.3. Fill in blank number ionization properties trend character become acidic non-metal basic across group properties carbonate silicon basic CHEMICAL CHARACTER In any (21) of the periodic table we have already noted that the 22) of electrons in the outermost shell is the same for each element and the (23) energy falls as the group is descended. This immediately predicts two likely (24) . of the elements in a group. The first property is their general similarity. Another one is the (25) towards metallic behavior as the group is descended. We shall see that these predicted (26) are borne out when we study the individual groups. Increasing metallic electropositive behavior down a group also implies a change in the (27).. of the oxides. They will be expected to (28). more basic as we descend the group and a change from an (29). oxide, i.e. an oxide of a (30). which readily reacts with OH~ or oxide ions to give oxo acid anions , to a 17 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh (31). oxide, i.e. one which readily yields cations, in some groups. The best example of such a change is shown by the Group IV elements; the oxides of carbon and (32). are acidic, readily forming (33) and silicate anions, whilst those of tin and lead are (34). giving such ions as Sn2+ and Pb2+ in acidic solution. Metallic character diminishes (35) .. a period and in consequence the oxides become more acidic as we cross a given period. This is clearly demonstrated in Period 3. II. Grammar THE ADJECTIVE CLAUSE An adjective clause is a subordinate clause used to modify a noun or a pronoun in the main clause. It may be introduced by the pronouns who, whose, whom, which, or that (and sometimes when or where). These pronouns are called relative pronouns because they relate to a noun or a pronoun in the sentence. Occasionally, no relative pronoun is used, but it is implied or understood. Identifying Adjective Clauses Note: Nouns are bolded, the adjective clauses are underlined. 1. Mike, whose ancestors came from Ireland, marched in the St. Patrick's Day parade. 2. The woman who lives next door is a registered nurse. 3. Williamsburg, Virginia, is a place that I'd like to visit 4. Math, which is Dave's favorite subject, has always been easy for him. 5. There is the house that I'd like to buy. 6. Larry's letter, which he mailed Tuesday, reached me on Thursday. 7. Summer, which is my favorite season, will be here in another week. 8. Phil is reading The Call of the Wild, which is Jack London's most famous book. 18 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh 9. We live just twenty miles from O'Hare Airport, which is the world's busiest airport. 10 Newton, Iowa, is the town where Barbara was born. 11. I'm taking golf lessons from Erika Lavery, who is a pro at the country club. 12. That dog that you found belongs to the Olsons. 13. Is that the jacket you want to buy? 14. There is a chance that Norm will win the election. 15. Is this the letter you were expecting? 16. Over there is the school that I attended. 17. Mr. Hartman is a history teacher who also coaches track. 18. Is that the antique show you visited? 19. The Harveys have a dog that is fourteen years old. 20. For dinner, we had chicken fried steak, which is my favorite dish. Exercise 36. Mendeleev had no idea what atoms were made of or why they behaved as they did. 37. Electronegativity is one of the most fundamental atomic parameters which express numerically the tendency to attract electrons to atoms in a molecule. 38. The Pauling scale, which was introduced first in 1932, is still the most frequently used. 39. Those elements which are hard to ionize and easy to attract electrons have large values 40. In the formation of a molecule, atomic orbitals overlap to generate a molecular orbital which is the wave function of the electrons in the molecule. 19 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh 41. The Group 6 to 10 transition metals that do not form binary hydrides give many hydride complexes with auxiliary ligands such as carbonyl and tertiaryphosphines. 42. Most of this silicon exists as a component of silicate rocks that is not found as a simple substance. 43. Oxygen, which is one of the most important gases for animals, is about 20% in atmosphere. 44. It is impossible to find potassium metal in nature where potassium can with water to form potassium cation. 45. s-Block elements have sodium element, which is a alkaline metal. 46. Beaker is the most popular glassware that is used in chemistry laboratory. 47. Halogens that are strongly oxidative elements are located in the group VII. 48. Sodium chloride that is easily dissolved in water causes the high pressure disease. 49. Higher-grade silicon is obtained by hydrogen reduction of SiHCl 3 , which is produced by the hydrochlorination of low purity silicon followed by rectification. 50. Silicates and organosilicon compounds that are shown a wide range of structures in silicon chemistry can be synthesized in laboratory. III. Translation III.1 Translate into Vietnamese 51. In 1884, Arrhenius defined that an acid is a substance that gives H + and a base one that gives OH - . 52. Namely, if an acid is HA and a base BOH, then HAH+ + A- and BOH  B + + OH - . 53. Therefore, when an acid and a base react, water is formed. 20 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh 54. In a new theory submitted in 1923 independently by Bronsted and Lowry, an acid is defined as a molecule or an ion which gives H + and a molecule or ion that receives H + from a partner is a base. 55. A base is not only a molecule or an ion which gives OH - but anything which receives H + . 56. The acid HA gives H + to water in an aqueous solution and generates an oxonium ion, H3O + . 57. Water is also a kind of base according to this definition. 58. Water can be an acid or base dependent on the co-reactant. 59. Although the definition of Bronsted-Lowry is not much different from that of Arrhenius for aqueous solutions, it is more useful because the theory was extended to non-aqueous acids and bases. 60. The strength of an acid in a dilute aqueous solution is estimated from the equilibrium constant Ka. III.2. Translate into English Oxidation number 61. Số oxy hóa là điện tích hình thức của một nguyên tử trong hợp chất. The oxidation number is the formal electrical charge of a component atom in a compound. 62. Nguyên tử có độ âm điện nhỏ hơn có điện tích dương. The atom with smaller electronegativity has a positive charge. 63. Số oxy hóa của nguyên tử có thể giống hay khác khi nó kết hợp với các nguyên tử khác nhau. The oxidation number can be different for the same atom combined with different partners. 64. Một dung môi có thể hoạt động như một axit hay một bazơ. A solvent also works as an acid or a base. 21 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh 65. Tính axit phụ thuộc vào dung môi hòa tan nó. The acidity and its range depend on the solvent dissolving the acid. 66. Sự phân li của một axit trong nước tạo ra H3O + trong dung dịch. Full dissociation of an acid gives H 3 O + in an aqueous solution. 67. Một số người nhầm lẫn phản ứng axit-bazơ và phản ứng oxi hóa khử. Some people confuse acid-base and redox reactions. 68. Sự nhầm lẫn có thể gây ra bởi cách gọi tương tự tự oxy và sự không hiểu về sự chuyển electron. This confusion may be caused firstly by the similar terms originating from oxygen and secondly by misunderstanding about electron transfer. 69. Trên phương diện lich sử, A. L Lavoisier là một trong những người tìm ra hóa học hiện đại tron g thế kỉ 18 cho rằng oxy là cơ sở của tất cả axit. Historically, A. L. Lavoisier, who was one of the great founders of modern chemistry in the 18th century, considered that oxygen was the basis of all acids. 70. A. L. Lavoisier cũng định nghĩa oxy hóa là sự hình thành oxit từ một nguyên tử và một oxy. He also defined oxidation as the formation of oxides from an element and oxygen. IV. Futher Reading Electronic structure of elements Wave functions of electrons in an atom are called atomic orbitals. An atomic orbital is expressed using three quantum numbers; the principal quantum number, n; the azimuthal quantum number, l; and the magnetic quantum number, m l . For a principal quantum number n, there are n azimuthal quantum numbers l ranging from 0 to n-1, and each corresponds to the following orbitals. 22 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh l: 0 1 2 3 4 s p d f g An atomic orbital is expressed by the combination of n and l. For example, n is 3 and l is 2 for a 3d orbital. There are 2l+1 ml values, namely, l, l-1, l-2, , -l. Consequently, there are one s orbital, three p orbitals, five d orbitals and seven f orbitals. The three aforementioned quantum numbers are used to express the distribution of the electrons in a hydrogen-type atom, and another quantum number ms (1/2, -1/2) which describes the direction of an electron spin is necessary to completely describe an electronic state. Therefore, an electronic state is defined by four quantum numbers (n, l, m l , m s ). The wave function ψ which determines the orbital shape can be expressed as the product of a radial wave function R and an angular wave function Y as follows. ψn,l,ml = Rn,l(r)Yl,ml(θ,φ) n. The following conditions must be satisfied when each orbital is filled with electrons. Electron filling is based on Pauli principle and Hund’s rule. Pauli principle: The number of electrons that are followed to occupy an orbital must be limited to one or two, and, for the latter case, their spins must be anti-parallel (different direction). Hund’s rule: orbitals, electrons occupy separate orbitals nd their spins are parallel (same direction). The order of orbital energy of a neutral atom is 1s < 2s < 2p < 3s < 3p < 4s < 3d < 4p and the electron configuration is determined as electrons occupy orbitals in this order according to the Pauli principle and Hund’s rule. An s orbital with one ml can accommodate 2 electrons, a p orbital with three ml 6 electrons, and a d orbital with five ml 10 electrons. For instant, describe the electron configuration of a C atom, an Fe atom, and a Au atom as below. 23 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh BÀI 4: THE ALKALI METALS Vocabulary radioactive emitting or relating to the emission of ionizing radiation or particles complexes an ion or molecule in which one or more groups are linked to a metal atom by coordinate bonds dissolve become or cause to become incorporated into a liquid so as to form a solution solution a liquid mixture in which the minor component (the solute) is uniformly distributed within the major component (the solvent) solvate enter into reversible chemical combination with (a dissolved molecule, ion, etc.). combustion the process of burning something: the combustion of fossil fuels. isolate obtain or extract (a compound, microorganism, etc.) in a pure form. electrolysis chemical decomposition produced by passing an electric current through a liquid or solution containing ions. exothermic (of a reaction or process) accompanied by the release of heat. The opposite of endothermic I: Reading comprehension Alkali metal salts, in particular sodium chloride, have been known since antiquity.However, due to the difficulty of reducing alkali metal ions, the elements were not isolated untilcomparatively recently. Potassium and sodium were first isolated in 1807 by Davy as products of the electrolysis of 24 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh molten KOH and NaOH. In 1818, Davy also isolated lithium by electrolysis of molten Li2O. Cesium and rubidium were discovered with the help of the spectroscope in 1860 and 1861, respectively. Francium was not identified until 1939 as a short-lived radioactive isotope from the nuclear decay of actinium. The alkali metals are silvery, except for cesium, which has a golden appearance. They are highly reactive solids with very low melting points. As other metals, the alkali metals are malleable, ductile, and are good conductors of heat and electricity. The chemical properties of the alkali metals are governed by the ease with which they can lose one electron and achieve a noble gas configuration. All alkali metals are excellent reducing agents.The metals react vigorously with water to form hydrogen; for example, 2 Na + 2H2O  NaOH + H2. This reaction is highly exothermic, and the hydrogen formed may ignite in air, sometimes explosively. Alkali metals react with oxygen to form oxides, peroxides, and superoxides, depending on the metal. Combustion in air of Na yields both Na2O and Na2O2, however, combustion of K only forms KO2. Alkali metals dissolve in liquid ammonia and other donor solvents, such as aliphatic amines (NR3, in which R = alkyl) and OP(NMe2)3, hexamethylphosphoramide, to give blue solutions believed to contain solvated electrons: Na + x NH3  Na + + e(NH3)x The blue color is attributed to the solvated electron (alkali metal ions are colorless). Also due to these solvated electrons, these solutions are paramagnetic and conduct electricity better than dissociated ionic compounds in aqueous solutions. Alkali metal cations can form complexes with a variety of Lewis bases. Of particular interest are cyclic Lewis bases that have several donor atoms that can complex, or trap, cations. These include a large group of cyclic ethers and a family of cryptands (or cryptates) I.1. Question: 1. Why weren’t alkali metals isolated since antiquity? 25 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh 2. Which Method did Dave use to isolate alkali metals? 3. What are possible products formed when sodium reacts with oxygen? 4. What is the color of Cesium? 5. What are solvated electrons? 6. Why is diluted solution of Sodium in ammonium paramagnetic? 7. How can an alkali metal obtain a noble gas configuration? 8. What are some physical properties of alkaline metals? 9. Which controls the chemical properties of alkali metals? 10. Why does diluted solution of Sodium in ammonium conduct electricity better than salt solution? I.2. True (T), false (F) or doesn’t say (DS) 11. The alkali metals were isolated in ancient time. 12 All alkali metals are silvery 13 Hexamethylphosphoramide is a donor solvent 14 Dilute solution of sodium in ammoniais better electrical conductor than salt solution. 15 Dilute solution of sodium in aliphaticaminesis an electrical conductor 16 cryptates are cyclic bases 17 Heat is released when Sodium reacts with Hydrogen 18 Cesium was isolated by Dave 26 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh 19 All alkali metals were isolated by a chemist named Dave 20 Sodium can react with O2 to form both oxide, peroxides, and superoxides 21 Sodium can dissolve in both water and ammonium 22 The alkali metal ions can be easily reduced by oxidizing agents. I.3. Fill in blank exothermic explode configurations solvated dissociate combustion Electrolysis reactive appears decays conductor unpaired complexes concentration reducing solvents isolate solution 21. Alkali metals are strong agents 22. Francium is a highly radioactive metal that into astatine, radium, and radon. 23. Alkali metals are very so that they do not occur freely in nature 24. Alkali metals can .if they are exposed to water. 25. Compared to Sodium, Cooper is a better electrical 26. Heat released in reaction of sodium and Hydrogen, which is , can cause explosion. 27. The electron ..of alkali metal ions are similar to those of inner gases. 28. Electrolysis of molten Li2O yields Li and O2. (or: Li can be prepare by electrolyzing molten Li2O) 27 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh 29. Ionic compounds can ion to positive and negative ions 30. In aqueous solutions, metal ions are by water molecules. 31. is a high-temperature exothermic chemical reaction between a fuel and an oxidant, usually atmospheric oxygen, that produces gaseous products in a mixture termed smoke. 32. The solution are paramagnetic due to the ..electrons 33. Cesium golden 34. .such as Cu(NH3)6 2+ have been known and studied since the mid- nineteenth century. 35. Alkali metal can dissolve in some .such as water, ammonium and aliphaticamines II. Grammar Put the verb into the correct form 36. If the alkali metal ions were reduced easily, they .in ancient time. (be isolated) 37. If hydrogen formed from reaction between Na and water. (ignite) in air, explosion can occur 38. What will happen if sodium..(expose) to water. 39. Cesium and rubidium .(discover) 1860 and 1861 without spectroscope. 40. If alkali metal ions (contain) solvated electrons, they (not be) colorless. Circle A, B, C or D to find a mistake in the four underlined parts of each sentence. Mark your choice on the answer sheet. (1.25 points). 41. Cesium and rubidium were named (A)as (B) the colors(C) of the most prominent emission(D) lines 28 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh 42. Inearly times (A), salt was used in the preserve(B) and flavoring (C) of food (D) 43. Alkali metals are enough soft (A)to be(B)cut(C)with(D) a knife or spatula. 44. The importance(A) of these structures were (B)recognized(C) when Cram, Pedersen, andLehn won (D) the Nobel Prize in Chemistry in 1987 45. The better the match(A) between the size of the cage and of (B) the metal ion, the more effectivelythe ion can be trapped(C)by (D) a cryptand. Rewrite these sentences so that the meaning does not change 46. I was not very careful when doing the experiment, so the explosion occurred If I .. 47. I forgot to store sodium in nonreactive oil, so it was oxided. If I 48. I did not know that 49. Without alkali metals in our body, we would die If there were no alkali metals in our body, we would die 50. Ingesting too much salt can lead to adverse side effects If you ingest too much salt, you can experience adverse side effects. III. Translation III.1 Translate into Vietnamese 51. Special precautions must be taken to prevent these metals from coming into contact with water 52. Alkali metals can all be cut easily with a knife due to their softness. 53. The chemistry of francium is not well established due to its extreme radioactivity. 29 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh 54. These elements were given the name "alkali" because they react with water to form hydroxide ions, creating basic solutions (pH>7), which are also called alkaline solutions. 55. 137 Cs undergoes high-energy beta decay and eventually becomes stable barium-137. 56. The alkaline earths Ca, Sr, and Ba and the lanthanides Eu and Yb also dissolve in liquid ammonia to give solvated electrons. 57. Special precautions must be taken to prevent the alkali metals from coming into contact with water. 58. Sodium and potassium, are essentialfor human life. 59. Partly due to their large atomic radii and low ionization energies, alkali metals are among the most reactive metals. 60. Alkali metals form multiple types of oxides, peroxides and superoxides when combined with oxygen. III.2. Translate into English 61. Dung dịch của kim loại kiềm trong amoniac có tính khử mạnh. Solutions of alkali metals in liquid ammonia are excellent reducing agents. 62. Arfvedson là người đầu tiên nhận ra sự giống nhau về độ tan giữa các hợp chất của Liti và Natri. Arfvedson was the first one who recognized similarities between the solubilities of compounds of lithium and those of sodium. 63. Các kim loại kiềm rất giống nhau về tính chất và hoá học. The alkali metals are very similar in their chemical and physical properties. 64. Phản ứng giữa natri và oxy là một phản ứng toả nhiệt. Reaction betwen sodium and oxygen is exothermic. 65. Liti florua là halide kim loại kiềm duy nhất không tan trong nước. Lithium fluoride is the only alkali metal halide that is not soluble in water. 66. Các kim loại kiểm thường được đựng trong dầu trơ để tránh bị oxi hoá 30 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh Alkali metals are ordinarily stored under nonreactive oil to prevent oxidation. 67. Muối Natri clorua được dùng trong mùa đông để hạn chế lượng tuyết trên đường. Sodium chloride is used during winter months to control the ice on the road. 68. Các kim loại kiềm phản ứng mãnh liệt với nước tạo ra bazo mạnh và khí Hidro Alkali metals and water react violently to form strong bases and hydrogen gas. 69. Liti thường được dùng trong các pin tự sạc được, bao gồm những loại pin dùng trong điện thoại cá nhân, máy quay phim, máy tính xách tay. Lithium is often used in rechargeable batteries, including those used in cell phones, camcorders, laptop computers. 70.Tất cả các kim loại kiềm đều có hoạt tính cao và không bao giờ được tìm thấy ở dạng nguyên tố trong tự nhiên. All the alkali metals are highly reactive and are never found in elemental forms in nature extra questions. 71. Kim loại kiềm phản ứng với các halogen tạo ra các muối ion. Alkali metals react with halogens to form ionic salts. 72. Tất cả các kim loại kiềm là những nguyên tố hoạt động mạnh và không bao giờ tìm thấy dạng nguyên tử trong tự nhiên. All the alkali metals are highly reactive and are never found in elemental forms in nature. 73. Francium có chu kì bán hủy ngắn và phân giã rất nhanh. Francium has a very short half-line (lifetime) and decays quickly 74. Các kim loại kiềm có ngọn lửa màu sang nên rất hữu dụng trong sản xuất pháo hoa. 31 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh The alkali metals' bright flame colors make them useful in firework manufacturing. 75. Natri clorua được sử dụng nhiều trong những tháng mùa đông để điều hòa tuyết (hay đã) trên đường bộ. Sodium chloride is used during winter months to control the ice on the road. 76. Kim loại kiềm được mô tả có tình mềm và màu ánh bạc. Alkali metals are characterized by their soft texture and silvery color. IV. Futher Reading Sodium Why is everyone so concerned about sodium these days? It’s an essential nutrient that the body uses to control blood pressure and blood volume. It is also needed for our muscles and nerves to work properly. Sodium occurs naturally in most foods. The most common form of sodium is sodium chloride, which is table salt. Milk, beets, and celery also naturally contain sodium, as does drinking water, although the amount varies depending on the source. Sodium is also added to various food products. Some of these added forms are monosodium glutamate, sodium nitrite, sodium saccharin, baking soda (sodium bicarbonate), and sodium benzoate. These found in items such as soy sauce, onion salt, garlic salt, and bouillon cubes. Processed meats, such as bacon, sausage, and ham, and canned soups and vegetables are all examples of foods that contain added sodium. Fast foods are generally very high in sodium. Taking too much sodium in the diet may lead to high blood pressure in some people or a serious build-up of fluid in people with congestive heart failure, cirrhosis, or kidney disease. Therefore, healthy adults should limit sodium intake to 2,300 mg per day. Adults with high blood pressure should have no more than 1,500 mg per day. Those with congestive heart failureand kidney disease may need much lower amounts. 32 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh BÀI 5: ANKANES I. Reading Comprehension General notes about alkanes Alkanes are composed of only carbon atoms and hydrogen atoms and contain only single bonds. Alkanes in which the carbons form a continuous chain with no branches are called straight-chain alkanes. The names of several straight-chain alkanes are given in the table below. Alkanes are widespread both on Earth and on other planets. The atmospheres of Jupiter, Saturn, Uranus, and Neptune contain large quantities of methane the smallest alkane, which is an odorless and flammable gas. In fact, the blue colors of Uranus and Neptune are due to methane in their atmospheres. Alkanes on Earth are found in natural gas and petroleum, which are formed by the decomposition of plant and animal materials that have been buried for long periods in the Earth’s crust, an environment with little oxygen. Natural gas and petroleum, therefore, are known as 33 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh fossil fuels. Natural gas consists of about 75% methane. The remaining 25% is composed of small alkanes such as ethane, propane, and butane. Petroleum is a complex mixture of alkanes and cycloalkanes that can be separated into fractions by distillation. The family of alkanes shown in the table is an example of a homologous series. A homologous series (homosis Greek for “the same as”) is a family of compounds in which each member differs from the next by one methylene group. The members of a homologous series are called homologs. Propane and butane are homologs. If you look at the relative numbers of carbon and hydrogen atoms in the alkanes listed in the table above, you will see that the general molecular formula for an alkane is CnH2n+2, where n is any integer. We have seen that carbon forms four covalent bonds and hydrogen forms only one covalent bond. This means that there is only one possible structure for an alkane with molecular formula CH4 (methane) and only one structure for an alkane with molecular formula C2H6 (ethane). There is also only one possible structure for an alkane with molecular formula C3H8 (propane). As the number of carbons in an alkane increases beyond three, the number of possible structures increases. There are two possible structures for an alkane with molecular formula C4H10. In addition to butane—a straight- chain alkane—there is a branched butane called isobutane. Compounds such as butane and isobutane that have the same molecular formula but differ in the 34 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh order in which the atoms are connected are called constitutional isomers— their molecules have different constitutions. There are five constitutional isomers with molecular formula C6H12. We are now able to name three of them (hexane, isohexane, and neohexane), but we cannot name the other two without defining names for new structural units (for more detail, see Further Reading part). Chemical properties of alkanes Alkanes have only strong σ bonds. Because the carbon and hydrogen atoms of an alkane have approximately the same electronegativity, the electrons in the C-C and C-H bonds are shared equally by the bonding atoms. Consequently, none of the atoms in an alkane have any significant charge. This means that neither nucleophiles nor electrophiles are attracted to them. Because they have only strong bonds and atoms with no partial charges, alkanes are very unreactive compounds. Their failure to undergo reactions prompted early organic chemists to call them paraffins, from the Latin parum affinis,which means “little affinity”(for other compounds). Alkanes do react with chlorine or bromine to form alkyl chlorides or alkyl bromides. These halogenation reactions take place only at high temperatures or in the presence of light (symbolized by hυ). They are the only reactions that alkanes undergo—with the exception of combustion, a reaction with oxygen that takes place at high temperatures and converts alkanes to carbon dioxide and water. 35 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh The mechanism for the halogenation of an alkane is well understood. The high temperature (or light) supplies the energy required to break the Cl-Cl or Br-Br bond homolytically. Homolytic bond cleavage is the initiation step of the reaction because it creates the radical that is used in the first propagation step. Recall that an arrowhead with one barb signifies the movement of one electron. A radical (often called a free radical) is a species containing an atom with an unpaired electron. A radical is highly reactive because it wants to acquire an electron to complete its octet. In the mechanism for the monochlorination of methane, the chlorine radical formed in the initiation step abstracts a hydrogen atom from methane, forming HCl and a methyl radical. The methyl radical abstracts a chlorine atom from forming methyl chloride and another chlorine radical, which can abstract a hydrogen atom from another molecule of methane. These two steps are called propagation steps because the radical created in the first propagation step reacts in the second propagation step to produce a radical that can repeat the first propagation step. Thus, the two propagation steps are repeated over and over. The first propagation step is the rate determining step of the overall reaction. Because the reaction has radical intermediates and repeating propagation steps, it is called a radical chain reaction. 36 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh I.1. Questions 1. An organic compound is classified as an alkane if it satisfies which cretaria? 2. How many kinds of alkanes are there if we classify them basing on their carbon chains? What are they? 3. How were alkanes on Earth formed? 4. What are the main components of natural gas? 5. What is the general molecular formula for the homologous series of alkanes? 6. Why do alkanes with higher number of carbons have more constitutional isomers than those with fewer carbons? 7. Why are ankanes so unreactive? 8. Under which conditions can alkanes be halogenated? 37 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh 9. What is the rate determining step of the overall radical halogenation reaction of alkanes? 10. What is the general characteristics of a radical reaction? I.2. TRUE (T), FALSE (F) and UNKNOWN statements No. Answer Statements 1  Compounds that contain only carbon and hydrogen are called hydrocarbons, so an alkane is a hydrocarbon that has only single bonds. 2  Alkanes can have only the straight carbon chains. 3  Alkanes on Earth were formed under anaerobic conditions. 4  Natural gas is considered as a fossil fuel as its components burn easily, accompanied by releasing of high amount of heat. 5  All alkanes have even numbers of hydrogens. 6  The higher the number of carbons in an alkane, the greater the number of possible constitutional isomers it has. 7  Alkanes have very low affinity with various reagents since they have only strong non-polar single bonds. 8  Alkanes do react with chlorine or bromine to form alkyl chlorides or alkyl bromides. These halogenation 9  Alkanes can react with halogens to form alkyl halides when 38 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh being heated or radiated with light of suitable wavelenghts. 10  When a mixture of an alkane and a halogen are heated at high temperature or radiated with light, the C-C and C-H are homolytically cleaved at the initiation step. I.3. Fill in each blank with one suitable word: 122 attraction electrons share reacts nucleophile electrophile reactivity functional accept electron-rich In essence, organic chemistry is about the interaction between (1).atoms or molecules and electron-deficient atoms or molecules. It is these forces of (2).. that make chemical reactions happen. From this follows a very important rule that determines the (3) of organic compounds: Electron-rich atoms or molecules are attracted to electron-deficient atoms or molecules. Each time you study a new (4) group, remember that the reactions it undergoes can be explained by this very simple rule. Therefore, to understand how a functional group reacts, you must first learn to recognize electron-deficient and electron-rich atoms and molecules. An electron- deficient atom or molecule is called an (5). An electrophile can have an atom that can (6) a pair of electrons, or it can have an atom with an unpaired electron and, therefore, is in need of an electron to complete its octet. Thus, an electrophile looks for (7).. Literally,“electrophile” means “electron loving” (phileis the Greek suffix for “loving”). 39 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh An electron-rich atom or molecule is called a (8). A nucleophile has a pair of electrons it can (9)... Some nucleophiles are neutral and some are negatively charged. Because a nucleophile has electrons to share and an electrophile is seeking electrons, it should not be surprising that they attract each other. Thus, the preceding rule can be restated as a nucleophile (10).. with an electrophile. Because an electrophile accepts a pair of electrons, it is sometimes called a Lewis acid. Because a nucleophile has a pair of electrons to share, it is sometimes called a Lewis base. II. Grammar Complete the following sentences using suitable form of comparison 1. If (many).. one substituent is attached to the parent hydrocarbon, the chain is numbered in the direction that will result in (low) possible number in the name of the compound. 2. When both directions lead to the same (low). number for one of the substituents, the direction is chosen that gives (low). possible number to one of the remaining substituents. 40 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh 3. If the same substituent numbers are obtained in both directions, the first group cited receives the (low) .. number. 4. If a compound has two or (much) chains of the same length, the parent hydrocarbon is the chain with (great).. number of substituents. 5. When there is only a substituent, the substituent gets (low).. possible number. When there is only a functional group suffix, the functional group suffix gets (low) possible number. When there is both a functional group suffix and a substituent, the functional group suffix gets (low).. possible number. 6. An alkyne is (reactive). an alkene. This might at first seem surprising because an alkyne is (stable). an alkene (see figure below). However, reactivity depends on ∆G‡ which in turn depends on the stability of the reactant and the stability of the transition state. For an alkyne to be both (stable) and (reactive). an alkene, two conditions must hold: The transition state for the first step (the rate-limiting step) of an electrophilic addition reaction for an alkyne must be (stable).. the transition state for the first step of an electrophilic addition reaction for an alkene. 41 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh 7. Allylic and benzylic cations have delocalized electrons, so they are (stable) similarly substituted carbocations with localized electrons. 8. Side-to-side overlap of in-phase p orbitals (lobes of the same color) produces a bonding molecular orbital. The bonding molecular orbital is (low) in energy the p atomic orbitals, and it encompasses both carbons. In other words, each electron in the bonding molecular orbital spreads over both carbon atoms. Side-to-side overlap of out- of-phase p orbitals produces an antibonding molecular orbital, which is (high) in energy . the p atomic orbitals. 9. We must also be aware that bromination is a much (slow). reaction chlorination. The activation energy for abstraction of a hydrogen atom by a bromine radical has been found experimentally to be about 4.5 times greater than that for abstraction of a hydrogen atom by a chlorine radical. 42 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh 10. The fluorine radical is (reactive) of the halogen radicals, and it reacts violently with alkanes. In contrast, the iodine radical is (reactive) of the halogen radicals. III. Translation III.1. Translate the following text into Vietnamese The description of the step-by-step process by which reactants (e.g., alkene + HBr) are changed into products (e.g., alkyl halide) is called the mechanism of the reaction. To help you understand a mechanism, curved arrows are drawn to show how the electrons move as new covalent bonds are formed and existing covalent bonds are broken. In other words, the curved arrows show which bonds are formed and which are broken. Because the curved arrows show how the electrons flow, they are drawn from an electron- rich center (at the tail of the arrow) to an electron-deficient center (at the point of the arrow). An arrowhead with two barbs represents the simultaneous movement of two electrons (an electron pair). An arrowhead with one barb represents the movement of one electron. These are called “curved” arrows to distinguish them from the “straight” arrows used to link reactants with products in chemical reactions. III.1. Translate the following text into English Các yếu tố ảnh hưởng đến tỉ lệ sản phẩm Các gốc ankyl được ổn định hóa bởi các nhóm ankyl đẩy electron, vì vậy, gốc ankyl bậc III bền hơn một gốc ankyl bậc II, và gốc ankyl bậc II bền hơn gốc ankyl bậc I. 43 Tài liệu tập huấn giảng viên dạy chuyên ngành bằng tiếng Anh Gốc tự do càng bền vững thì nó càng dễ hình thành, vì độ bền của gốc ankyl tự do được thể hiện ở độ bền của trạng thái chuyển tiếp dẫn đến sự tạo thành gốc đó. Kết quả là, việc tách một nguyên tử H dẫn đến sự tạo thành gốc bậc II dễ dàng hơn sự tách H dẫn đến sự tạo thành một gốc tự do bậc I. Để xác định được hàm lượng tương đối các sản phẩm tạo thành trong phản ứng clo hóa ankan, cần tính đến cả hai yếu tố xác xuất (số lượng nguyên tử H cùng loại có thể bị tách để dẫn đến sự hình thành của một sản phẩm nào đó) và khả năng phản ứng (tốc độ tương đối khi tách một nguyên tử H). Khi cả hai yếu tố trên cùng được tính đến thì hàm lượng theo tính toán phù hợp với lượng thu được từ thực nghiệm.