华中师范大学化学专业英语课件7
有机化学英文课件chapter7
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Allene
Allene: a compound containing a C=C=C group
• the simplest allene is 1,2-propadiene, commonly named allene
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Allenes
• most allenes are less stable than their isomeric alkynes, and are generally only minor products in alkyne-forming dehydrohalogenation reactions
• terminal alkynes react with sodium amide to form alkyne anions
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Acidity
• terminal alkynes can also be converted to alkyne anions by reaction with sodium hydride or lithium diisopropylamide (LDA)
• alkylation can be repeated and a terminal alkyne can be converted to an internal alkyne
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which the alkyne and halogen acid are mixed
《化学专业英语》课件
3 科研文献
能够阅读和理解化学领域 的英文文献，获取最新的 研究进展。
课程目标
提升英语水平
通过学习化学英语，提高学生的听、说、读、写的综合能力。
培养专业素养
掌握化学领域的专业知识，培养化学专业人才的国际视野和发展潜力。
拓宽就业机会
提高毕业生的就业竞争力，拓宽就业选择的广度和深度。
课程内容
化学基础
《化学专业英语》PPT课 件
化学专业英语是一门专门针对化学领域的英语课程，涵盖了化学专业学习所 需的英语知识、技能和应用。
什么是化学专业英语？
1 跨学科领域
2 专业术语
将化学与英语语言相结合， 培养学生在国际化舞台上 的沟通和交流能力。
学习化学中常用的英语词 汇和术语，并能准确运用 于实际工作和研究中。
通过背诵、使用单词卡等方法，扩充化学英语词汇量。
2
听力训练
听取相关英语化学课程、学术演讲和访谈，提高听力能力。
3
写作练习
撰写化学实验报告、研究论文、科研项目等，培养写作能力。
考核方式
课堂表现
参与讨论、展示课堂作业、 个人表现评价等。
考试测试
期中考试、期末考试、词汇 测试等。
作业报告
化学实验报告、论文撰写等。
结语
通过学习《化学专业英语》课程，学生将掌握化学领域所需的英语知识和技 能，为未来的学术研究和工作打下坚实的基础。
化学方程式、元素周期表、化 合物命名等。
实验技术
实验室操作、仪器仪表使用、 数据处理等。
专业文献
学术论文阅读、科研资料查找、 文献翻译等。
学习资源
教材
《化学专业英语教程》、《化学 英语词汇手册》等。
化学专业英语 高教ppt
carbonic hypochloric periodic acid acid acid 碳酸 次氯酸 高碘酸
Some of the common methods used for decomposing and
dissolving samples for atomic absorption methods include treatment with hot mineral acids; oxidation with liquid reagents,
Abstract: Chemical studies of interaction between 6mercaptopurine (巯基嘌呤) and DNA were performed in this paper. It was found that both reduction and oxidation peak currents decreased and the peak potential also shifted positively with the increasing of time and DNA concentration, respectively. The result showed that the DNA reacted with 6-MP to form an electrochemical non-active complex. The composition of the complex was 1:1, with the combining constant of 5.17×106.
When copper and tin were heated together, the copper atoms and tin atoms linked up with metallic bonds, producing the alloy bronze, which is harder than either copper or tin. In the Bronze Age, starting at about 3600BC, the hardness of this metallic alloy made it the dominant material for tools and weapons. Bronze was the first metal that could hold a sharp edge.
专业英语有机化学PPT 终极修改版
• 根据烷烃的化学性质可进行的反应： • • 氧化反应 oxidation reaction • 取代反应 substitution reaction • 裂化反应 cracking reaction
2.烯烃 2.烯烃 C=C
• 烯烃是指含有C=C键（碳-碳双键）（烯键）的碳 氢化合物。烯烃的物理性质可以与烷烃对比。物 理状态决定于分子质量。简单的烯烃中，乙烯、 丙烯和丁烯是气体，含有五至十六个碳原子的直 链烯烃是液体。 • 烯烃C=C的性质决定它比较容易发生的化学反应 有： • 加氢反应 Hydrogenation • 亲电加成反应 Hydrogenation • 氧化反应 oxidation reaction • 聚合反应 polyreaction
烯烃命名规律
命名： • 1.只有一个双键的不饱和烯烃的命名是通 过把相对应烷烃后面的“-ane”用“-ene”代替。 • 2.如果含有两个以上的双键，则用“-andiene” 和“-atriene”代替ane。 • • • • • • 乙烯methene 丙烯propene 戊烯 pentene 己烯hexene 丙基乙烯 propyl ethylene 1,4己二烯 1,4-hexandiene
• 羧酸的命名 一般是ห้องสมุดไป่ตู้基团的后面直接加上--acid • Examples: • 甲酸 formic acid 酸 • 乙酸 acetic acid • 丙酸 propionic acid • 丁酸 butyric acid • 己酸 caproic acid 酸 • 己二酸 adipic acid 酸 • 癸酸 decanoic acid 酸 • 草酸 oxalic acid 酸
5.醇和酚 5.醇和酚 alcohol and phenol
化学英语课件
( )：
[ ]： { }：
rounds brackets, parenthese
square brackets braces
a>>b: a is much greater than b ab： a is greater than or equal to b
ab： a varies directly as b
P-block Element
IIIA B: boron Al: Aluminium Ga: Gallium In: Indium Tl: Thallium
IVA C: Si: Ge: Sn: Pb:
VA
Carbon Silicon Germanium Tin Lead
N: P: As: Sb: Bi:
3. fundamental constants
Symbol Quantity
e
F g
elementary charge
Faraday‘s constant gravitational acceleration
h
k NA R Vm
Planck‘s constant
Boltzmann‘s constant Avogadro‘s number molar gas constant gas molar volume
Nitrogen Phosphorus Arsenic Antimony Bismuth
P-block Element
VIA O: S: Se: Te: Po:
VIIA Oxygen Sulfur Selenium Tellurium Polonium
F: Fluorine Cl: Chlorine Br: Bromine I: Iodine At: Astatine
化学相关专业英语(课堂PPT)
❖ Scientific disciplines represent abstract bodies of knowledge(科 学学科代表知识体)
❖ Technology is the physical application of scientific knowledge to
the production of new products to improve human survival, comfort(n. 安慰；舒适；使人舒服的事ቤተ መጻሕፍቲ ባይዱ；给予援助或安慰的人或事
English Curse of Chemistry
Huiming L1in
教材：
1、《化学专业英语》
（周光明，西南师范大学出版社）
2、《化学专业基础英语》
（魏高原，北京大学出版社）
3、《化学与化工英语》
（张荣，华中科技大学出版社）
4、《化学与应用化学专业英语》 (王辛宜，华东理工大学出版社)
2
Why must we study the course? The content of the course
❖ ) pace(n. 一步；长度单位；步幅，步调；快步
vt. 踱步，走来走去；步测；调整步调；训练马溜蹄 vi. 踱；溜蹄 prep.
蒙…恩准，怀着对…的敬意), to have a major impact on human
society)技术是科学知识来生产新的产品来改善人类的生存，舒适的物
理应用，和生活质量（技术进步开始影响我国社会约200年，和新的进
6
what is chemistry and why is it important
➢ Why is it important chemistry plays a pivotal role in the natural sciences. It provides the essential basic knowledge for applied sciences, such as astronomy, materials sciences, chemical engineering, agriculture, medical sciences and pharmacology.
化学专业英语ppt课件
soapy 肥皂般的，滑腻的 slippery 滑的 neutralization 中和 evaporation 蒸发 positive 正的，阳的 positive ion 正离子 negative ion 负离子 lattice 格子，点阵 crystal lattice 晶格 electrovalent 电价的 orient 定向，取向 pattern 模型，形式
4
• thousands and tens of thousands成千上万
The Classes of Compounds Thousands and tens of thousands of compounds are known to the chemist today.
be known to被……所知
幸运的是，大多数化合物能够组合在一起分成几类。
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Then, if we can properly classify a compound, we are at once aware of the general properties of the compound from knowledge of the properties of that class or group of compounds.
share 共享，分享 transfer 转移 coordinate 配位
coordinate valence 配键 hydronium ion 水合氢离子
citric 柠檬的 citric acid 柠檬酸 citrus 柑桔属
lactic 乳的 lactic acid 乳酸
2
litmus 石蕊 litmus paper 石蕊试纸 dye 染料 soak 浸泡，浸渍 enable 使……能够 indicator 指示剂 methyl 甲基 methyl orange 甲基橙 phenolphthalein 酚酞 react (with, on) 反应 strong acid 强酸 ionize 离子化，电离 bitter 苦味
化学专业英语详细版.ppt
•a fraction of 一小部分 •on the basis of 根据……, 在……基础上
如果根据个别化合物来了解这么多化合
物的性质，即使其中的一小部分也是不可
能的。
.精品课件.
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Fortunately, most chemical compounds can be grouped together in a few classes.
dቤተ መጻሕፍቲ ባይዱne on the basis of individual compounds. Fortunately, most
chemical compounds can be grouped together in a few classes.
Then, if we can properly classify a compound, we are at once
usually a metal. Ex., NaOH, Ca(OH)2, Fe(OH)3.
3. A salt consists of a metal, written first, combined
with a non-metal or radical written last in a formula.
• be aware of 知道，意识到……
那么，如果我们能够恰当地将一个化合物归类，我们立
刻就能从这类化合物的性质来了解这个化合物的一般性 质。
.精品课件.
8
For example, HCl is classed as an acid, and by becoming familiar with the behavior of acids as a distinct class, we are at once aware of the general properties of the compound.
化学专业英语课件市公开课一等奖省赛课微课金奖PPT课件
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化学专业英语课件
Nomenclature of Organic Compounds （有机化合物命名法）
1. Nomenclature of Hydrocarbons:（烃类命 名法）
1）Aliphatic Hydrocarbons（Fatty Hydrocarbons ，脂肪烃）
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g. 支链烃类（hydrocarbon with branched chains）命名：
i). 以最长碳链为主链，从一端向另一端编号 ，使侧链含有最低编号。如有几个侧链，按 侧链取代基字头英文字母次序排列。
例：CH3(CH2)3CHCH(CH2)2CH3 ：
d. 炔烃（alkyne ）命名： 数字头 + -yne（有时是-ine）.
（以a结尾数字头去a加-yne .） * 多炔命名: 二炔类--- 数字头 + -diyne .
例: 乙炔: ethyne; 丁炔: butine; 己二炔: hexadiyne 或 hexadiine
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e. 脂环烃（alicyclic hydrocarbons）命名： 烃类名称前 + cyclo-
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2. Names of Anions（阴离子命名）
1） Monatomic anions（单原子阴离子）： 元素名称词干 + -ide + ion
例：F-：fluoride ion（F：fluorine）；Cl-： chloride ion（Cl：chlorine）；
有机化学英文课件chapter7
William H. Brown Christopher S. Foote Brent L. Iverson
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Alkynes
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Hydroboration
Addition of borane to an internal alkyne gives a trialkenylborane
• addition is syn stereoselective
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approximately 155°, indicating high angle strain
M a c in to s h P IC T M acintosh PICT im age form at is not supported
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is not supported
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Cycloalkynes
Cyclononyne is the smallest cycloalkyne isolated
• it is quite unstable and polymerizes at room temp • the C-C-C bond angle about the triple bond is
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化学专业英语课件
题型多样：选择题、填空 题、简答题等
难度适中：适合不同水平 的学生
内容丰富：涵盖化学专业 各个领域
答案解析：详细解答，帮 助学生理解知识点
《化学专业英语》：由化学工业 出版社出版，内容全面，适合初 学者
《化学专业英语阅读》：由化学 工业出版社出版，精选了大量化 学专业英语文章，适合提高阅读 能力
实验步骤：详 细描述实验步 骤，包括仪器、 试剂、操作等
实验结果：描 述实验结果， 包括数据、图
表、结论等
实验讨论：分 析实验结果， 提出假设、解
释、结论等
实验报告：撰 写实验报告， 包括实验目的、 方法、结果、 讨论、结论等
阅读目的：了 解研究领域最 新进展，掌握
研究方法
阅读技巧：快 速浏览摘要、 引言和结论， 详细阅读实验
提高化学专业学 生的英语水平
帮助学生理解化 学专业术语和概 念
增强学生的跨文 化交流能力
提高学生的学术 研究和论文写作 能力
化学专业学 生
化学研究人 员
化学教师
对化学感兴 趣的人士
内容全面：涵盖化学专业的基础知识、实验操作、研究方法等
语言地道：采用专业英语，有助于提高学生的英语水平
互动性强：提供丰富的案例、实验、讨论等互动环节，提高学生的学 习兴趣 实用性强：结合实际应用，帮助学生更好地理解和掌握化学专业知 识
汇报人：PPT
添加标题 lusion
阅读目的：了解化学领域的最新研究成果和趋势 阅读方法：选择合适的文献来源，如学术期刊、会议论文等 阅读技巧：注意关键词、摘要、结论等关键信息，提高阅读效率 阅读后思考：对文献内容进行总结和思考，提出自己的观点和见解
联想记忆法：将新词汇与已知词汇或生活场景联系起来记忆
化学专业英语电子版
Chapter 1 Matter and MeasurementChemistry is the science of matter and the changes it undergoes. Chemists study the composition, structure, and properties of matter. They observe the changes that matter undergoes and measure the energy that is produced or consumed during these changes. Chemistry provides an understanding of many natural events and has led to the synthesis of new forms of matter that have greatly affected the way we live.Disciplines within chemistry are traditionally grouped by the type of matter being studied or the kind of study. These include inorganic chemistry, organic chemistry, physical chemistry, analytical chemistry, polymer chemistry, biochemistry, and many more specialized disciplines, e.g. radiochemistry, theoretical chemistry.Chemistry is often called "the central science" because it connects the other natural sciences such as astronomy, physics, material science, biology and geology.1.1. Classification of MatterMatter is usually defined as anything that has mass and occupies space. Mass is the amount of matter in an object. The mass of an object does not change. The volume of an object is how much space the object takes up.All the different forms of matter in our world fall into two principal categories: (1) pure substances and (2) mixtures. A pure substance can also be defined as a form of matter that has both definite composition and distinct properties. Pure substances are subdivided into two groups: elements and compounds. An element is the simplest kind of material with unique physical and chemical properties; it can not be broken down into anything simpler by either physical or chemical means. A compound is a pure substance that consists of two or more elements linked together in characteristic and definite proportions; it can be decomposed by a chemical change into simpler substances with a fixedmass ratio. Mixtures contain two or more chemical substances in variable proportions in which the pure substances retain their chemical identities. In principle, they can be separated into the component substances by physical means, involving physical changes. A sample is homogeneous if it always has the same composition, no matter what part of the sample is examined. Pure elements and pure chemical compounds are homogeneous. Mixtures can be homogeneous, too; in a homogeneous mixture the constituents are distributed uniformly and the composition and appearance of the mixture are uniform throughout. A solutions is a special type of homogeneous mixture. A heterogeneous mixture has physically distinct parts with different properties. The classification of matter is summarized in the diagram below:Matter can also be categorized into four distinct phases: solid, liquid, gas, and plasma. The solid phase of matter has the atoms packed closely together. An object that is solid has a definite shape and volume that cannot be changed easily. The liquid phase of matter has the atoms packed closely together, but they flow freely around each other. Matter that is liquid has a definite volume but changes shape quite easily. Solids and liquids are termed condensed phases because of their well-defined volumes. The gas phase of matter has the atoms loosely arranged so they can travel in and out easily. A gas has neither specific shape nor constant volume. The plasma phase of matter has the atoms existing in an excited state.1.2. Properties of MatterAll substances have properties, the characteristics that give each substance its unique identity. We learn about matter by observing its properties. To identify a substance, chemists observe two distinct types of properties, physical and chemical, which are closely related to two types of change that matter undergoes.Physical properties are those that a substance shows by itself, without changing into or interacting with another substance. Some physical properties are color, smell, temperature, boiling point, electrical conductivity, and density. A physical change is a change that does not alter the chemical identity of the matter. A physical change results in different physical properties. For example, when ice melts, several physical properties have changed, such as hardness, density, and ability to flow. But the sample has not changed its composition: it is still water.Chemical properties are those that do change the chemical nature of matter. A chemical change, also called a chemical reaction, is a change that does alter the chemical identity of the substance. It occurs when a substance (or substances) is converted into a different substance (or substances). For example, when hydrogen burns in air, it undergoes a chemical change because it combines with oxygen to form water.Separation of MixturesThe separation of mixtures into its constituents in a pure state is an important process in chemistry. The constituents of any mixture can be separated on the basis of their differences in their physical and chemical properties, e.g., particle size, solubility, effect of heat, acidity or basicity etc.Some of the methods for separation of mixtures are:(1)Sedimentation or decantation. To separatethe mixture of coarse particles of a solidfrom a liquid e.g., muddy river water.(2)Filtration. To separate the insoluble solidcomponent of a mixture from the liquidcompletely i.e. separating the precipitate(solid phase) from any solution.(3)Evaporation. To separate a non-volatilesoluble salt from a liquid or recover thesoluble solid solute from the solution.(4)Crystallization. To separate a solidcompound in pure and geometrical form.(5)Sublimation. To separate volatile solids,from a non-volatile solid.(6)Distillation. To separate the constituents of aliquid mixture, which differ in their boilingpoints.(7)Solvent extraction method. Organiccompounds, which are easily soluble inorganic solvents but insoluble or immisciblewith water forming two separate layers canbe easily separated.1.3 Atoms, Molecules and CompoundsThe fundamental unit of a chemical substance is called an atom. The word is derived from the Greek atomos, meaning “undivisible”or “uncuttable”.An atom is the smallest possible particle of a substance.Molecule is the smallest particle of a substance that retains the chemical and physical properties of the substance and is composed of two or more atoms;a group of like or different atoms held together by chemical forces. A molecule may consist of atoms of a single chemical element, as with oxygen (O2), or of different elements, as with water (H2O).A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. The term is also used to refer to a pure chemical substance composed of atoms with the same number of protons. Until March 2010, 118 elements have been observed. 94 elements occur naturally on earth, either as the pure element or more commonly as a component in compounds. 80 elements have stable isotopes, namely all elements with atomic numbers 1 to 82, except elements 43 and 61 (technetium and promethium). Elements with atomic numbers 83 or higher (bismuth and above) are inherently unstable, and undergo radioactive decay. The elements from atomic number 83 to 94 have no stable nuclei, but are nevertheless found in nature, either surviving as remnants of the primordial stellar nucleosynthesisthat produced the elements in the solar system, or else produced as short-lived daughter-isotopes through the natural decay of uranium and thorium. The remaining 24 elements so are artificial, or synthetic, elements, which are products of man-induced processes. These synthetic elements are all characteristically unstable. Although they have not been found in nature, it is conceivable that in the early history of the earth, these and possibly other unknown elements may have been present. Their unstable nature could have resulted in their disappearance from the natural components of the earth, however.The naturally occurring elements were not all discovered at the same time. Some, such as gold, silver, iron, lead, and copper, have been known since the days of earliest civilizations. Others, such as helium, radium, aluminium, and bromine, were discovered in the nineteenth century. The most abundant elements found in the earth’s crust, in order of decreasing percentage, are oxygen, silicon, aluminium, and iron. Others present in amounts of 1% or more are calcium, sodium, potassium, and magnesium. Together, these represent about 98.5% of the earth’s crust.The nomenclature and their origins of all known elements will be described in Chapter 2.A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together in a defined spatial arrangement by chemical bonds. Compounds that exist as molecules are called molecular compounds. An ionic compound is a chemical compound in which ions are held together in a lattice structure by ionic bonds. Usually, the positively charged portion consists of metal cations and the negatively charged portion is an anion or polyatomic ion.The relative amounts of the elements in a particular compound do not change: Every molecule of a particular chemical substance contains acharacteristic number of atoms of its constituent elements. For example, every water molecule contains two hydrogen atoms and one oxygen atom. To describe this atomic composition, chemists write the chemical formula for water as H2O.The chemical formula for water shows how formulas are constructed. The formula lists the symbols of all elements found in the compound, in this case H (hydrogen) and O (oxygen). A subscript number after an element's symbol denotes how many atoms of that element are present in the molecule. The subscript 2 in the formula for water indicates that each molecule contains two hydrogen atoms. No subscript is used when only one atom is present, as is the case for the oxygen atom in a water molecule. Atoms are indivisible, so molecules always contain whole numbers of atoms. Consequently, the subscripts in chemical formulas of molecular substances are always integers. We explore chemical formulas in greater detail in Chapter 2.The simple formula that gives the simplest whole number ratio between the atoms of the various elements present in the compound is called its empirical formula. The simplest formula that gives the actual number of atoms of the various elements present in a molecule of any compound is called its molecular formula. Elemental analysis is an experiment that determines the amount (typically a weight percent) of an element in a compound. The elemental analysis permits determination of the empirical formula, and the molecular weight and elemental analysis permit determination of the molecular formula.1.4. Numbers in Physical Quantities1.4.1. Measurement1.Physical QuantitiesPhysical properties such as height, volume, and temperature that can be measured are called physical quantity. A number and a unit of defined size are required to describe physical quantity, for example, 10 meters, 9 kilograms.2.Exact NumbersExact Numbers are numbers known withcertainty. They have unlimited number of significant figures. They arise by directly counting numbers, for example, the number of sides on a square, or by definition:1 m = 100 cm, 1 kg = 1000 g1 L = 1000 mL, 1 minute = 60seconds3.Uncertainty in MeasurementNumbers that result from measurements are never exact. Every experimental measurement, no matter how precise, has a degree of uncertainty to it because there is a limit to the number of digits that can be determined. There is always some degree of uncertainty due to experimental errors: limitations of the measuring instrument, variations in how each individual makes measurements, or other conditions of the experiment.Precision and AccuracyIn the fields of engineering, industry and statistics, the accuracy of a measurement system is the degree of closeness of measurements results to its actual (true) value. The precision of a measurement system, also called reproducibility or repeatability, is the degree to which repeated measurements under unchanged conditions show the same results. Although the two words can be synonymous in colloquial use, they are deliberately contrasted in the context of the scientific method.A measurement system can be accurate but not precise, precise but not accurate, neither, or both. A measurement system is called valid if it is both accurate and precise. Related terms are bias (non-random or directed effects caused by a factor or factors unrelated by the independent variable) and error(random variability), respectively. Random errors result from uncontrolled variables in an experiment and affect precision; systematic errors can be assigned to definite causes and affect accuracy. For example, if an experiment contains a systematic error, then increasing the sample size generally increases precision but does not improve accuracy. Eliminating the systematic error improves accuracy but does not change precision.1.4.2 Significant FiguresThe number of digits reported in a measurement reflects the accuracy of the measurement and the precision of the measuring device. Significant figures in a number include all of the digits that are known with certainty, plus the first digit to the right that has an uncertain value. For example, the uncertainty in the mass of a powder sample, i.e., 3.1267g as read from an “analytical balance” is 0.0001g.In any calculation, the results are reported to the fewest significant figures (for multiplication and division) or fewest decimal places (addition and subtraction).1.Rules for deciding the number of significantfigures in a measured quantity:The number of significant figures is found by counting from left to right, beginning with the first nonzero digit and ending with the digit that has the uncertain value, e.g.,459 (3) 0.206 (3) 2.17(3) 0.00693 (3) 25.6 (3) 7390 (3) 7390. (4)(1)All nonzero digits are significant, e.g., 1.234g has 4 significant figures, 1.2 g has 2significant figures.(2)Zeroes between nonzero digits aresignificant: e.g., 1002 kg has 4 significantfigures, 3.07 mL has 3 significant figures.(3)Leading zeros to the left of the first nonzerodigits are not significant; such zeroes merelyindicate the position of the decimal point:e.g., 0.001 m has only 1 significant figure,0.012 g has 2 significant figures.(4)Trailing zeroes that are also to the right of adecimal point in a number are significant:e.g., 0.0230 mL has 3 significant figures,0.20 g has 2 significant figures.(5)When a number ends in zeroes that are notto the right of a decimal point, the zeroes arenot necessarily significant: e.g., 190 milesmay be 2 or 3 significant figures, 50,600calories may be 3, 4, or 5 significant figures.The potential ambiguity in the last rule can be avoided by the use of standard exponential, or "scientific" notation. For example, depending onwhether the number of significant figures is 3, 4, or 5, we would write 50,600 calories as:5.06 × 104 calories (3 significant figures)5.060 ×104calories (4 significant figures), or5.0600 × 104 calories (5 significant figures).2.Rules for rounding off numbers(1)If the digit to be dropped is greater than 5,the last retained digit is increased by one.For example, 12.6 is rounded to 13.(2)If the digit to be dropped is less than 5, thelast remaining digit is left as it is. Forexample, 12.4 is rounded to 12.(3)If the digit to be dropped is 5, and if anydigit following it is not zero, the lastremaining digit is increased by one. Forexample, 12.51 is rounded to 13.(4)If the digit to be dropped is 5 and isfollowed only by zeroes, the last remainingdigit is increased by one if it is odd, but leftas it is if even. For example, 11.5 is roundedto 12, 12.5 is rounded to 12.This rule means that if the digit to be dropped is 5 followed only by zeroes, the result is always rounded to the even digit. The rationale is to avoid bias in rounding: half of the time we round up, half the time we round down.3.Arithmetic using significant figuresIn carrying out calculations, the general rule is that the accuracy of a calculated result is limited by the least accurate measurement involved in the calculation.(1) In addition and subtraction, the result is rounded off to the last common digit occurring furthest to the right in all components. Another way to state this rules, is that, in addition and subtraction, the result is rounded off so that it has the same number of decimal places as the measurement having the fewest decimal places. For example,100 (assume 3 significant figures) + 23.643 (5 significant figures) = 123.643,which should be rounded to 124 (3 significant figures).(2) In multiplication and division, the resultshould be rounded off so as to have the same number of significant figures as in the component with the least number of significant figures. For example,3.0 (2 significant figures ) ×12.60 (4 significant figures) = 37.8000which should be rounded off to 38 (2 significant figures).1.4.3 Scientific NotationScientific notation, also known as standard form or as exponential notation, is a way of writing numbers that accommodates values too large or small to be conveniently written in standard decimal notation.In scientific notation all numbers are written like this:a × 10b("a times ten to the power of b"), where the exponent b is an integer, and the coefficient a is any real number, called the significant or mantissa (though the term "mantissa" may cause confusion as it can also refer to the fractional part of the common logarithm). If the number is negative then a minus sign precedes a (as in ordinary decimal notation).In standard scientific notation the significant figures of a number are retained in a factor between 1 and 10 and the location of the decimal point is indicated by a power of 10. For example:An electron's mass is about 0.00000000000000000000000000000091093822 kg. In scientific notation, this is written 9.1093822×10−31 kg.The Earth's mass is about 5973600000000000000000000 kg. In scientific notation, this is written 5.9736×1024 kg.1.5 Units of Measurement1.5.1 Systems of Measurement1.United States Customary System (USCS)The United States customary system (also called American system) is the most commonly used system of measurement in the United States. It is similar but not identical to the British Imperial units. The U.S. is the only industrialized nation that does not mainly use the metric system in its commercial and standards activities. Base units are defined butseem arbitrary (e.g. there are 12 inches in 1 foot)2.MetricThe metric system is an international decimalized system of measurement, first adopted by France in 1791, that is the common system of measuring units used by most of the world. It exists in several variations, with different choices of fundamental units, though the choice of base units does not affect its day-to-day use. Over the last two centuries, different variants have been considered the metric system. Metric units are universally used in scientific work, and widely used around the world for personal and commercial purposes. A standard set of prefixes in powers of ten may be used to derive larger and smaller units from the base units.3.SISI system (for Système International) was adopted by the International Bureau of Weights and Measures in 1960, it is a revision and extension of the metric system. Scientists and engineers throughout the world in all disciplines are now being urged to use only the SI system of units.1.5.2 SI base unitsThe SI is founded on seven SI base units for seven base quantities assumed to be mutually independent, as given in Table 1.1.Table 1.1 SI Base Physical Quantities and UnitsU n i tN a m e UnitSymbolBaseQuantityQuantitySymbolDimensionSymbolm m l l Le t e r e n g t hk i lo g r a m kgmassm Ms ec o nd stimet Ta mp e r e AelectriccurrentI Ik el v i n KthermodynTΘm i ct e m p e r a t u r em o l e molamountofsubstancen Nc an d e l a cdluminousIvJntensity1.5.3 SI derived unitsOther quantities, called derived quantities, aredefined in terms of the seven base quantities via asystem of quantity equations. The SI derived unitsfor these derived quantities are obtained from theseequations and the seven SI base units. Examples ofsuch SI derived units are given in Table 1.2, where itshould be noted that the symbol 1 for quantities ofdimension 1 such as mass fraction is generallyomitted.Table 1.2 SI Derived Physical Quantities and(symbol) Unit(symbol)UArea (A) squaremeterm V olume (V) cubicmeterm Density (ρ) kilogramper cubicmeterkVelocity (u) meterpersecondmPressure (p) pascal(Pa)kEnergy (E) joule (J) (k Frequency (ν) hertz(Hz)1Quantity of electricity (Q) coulomb(C)AElectromotive force (E) volt (V) (kmsForce (F) newton(N)kFor ease of understanding and convenience, 22SI derived units have been given special names andsymbols, as shown in Table 1.3.Table 1.3 SI Derived Units with special names andsymbolsD e r i v e dq u a n t i t y SpecialnameSpecialSymbolExpressionintermsofotherSIunitsSIbaseunitsp r r ml a n ea n g l e adianad·m-1=1s o l i da n g l e steradiansrm2·m-2=1f r e q u e n c y hertzHzs-1f o r c e newtonN m·kg·s-2p p P N mr e s s u r e ,s t r e s s ascala/m21·kg·s-2e n e r g y ,w o r k ,q u a n t i t yo fh e a jouleJ N·mm2·kg·s-2p o w e r ,r a d i a n tf l u x wattW J/sm2·kg·s-3e l e c t r i cc h a r g e q u a n t i t y coulombC s·Afe l e c t r i c i t ye l e c t r i cp o t e n t i a l ,p o t e n t i a l voltV W/Am2·kg·s-3·A-1i f f e r e n c e ,e l e c t r o m o t i v ef o r c ec a p a c i t a n c e faradF C/Vm-2·kg-1·s 4·A 2e l e c t r i cr e s i s t a n c e ohmΩV/Am2·kg·s-3·A-2e l e c t r i cc o nd u c t a n c siemensS A/Vm-2·kg-1·s2·Aem a g n e t i cf l u x weberWbV·sm2·kg·s-2·A-1m a g n e t i cf l u xd e n s i t y teslaT Wb/m2kg·s-2·A-1i n d henH Wb/m2u c t a n c e ryA ·kg·s-2·A-2C e l s i u st e m p e r a t u r e degreeCelsius°CKl u m i n o u s lumenlmcd·srcd·srl u xi l l u m i n a n c e luxlxlm/m2m-2·cd·sra c t i v i t y( o far a d i o n u c l i d e becquerelBqs-1a b s o r b e dd o se ,s p e c i f i ce n e r g y( i m p a r t e d ) ,grayGyJ/kgm2·s-2e r m ad o s ee q u i v a l e n t ,e ta l .sievertSvJ/kgm2·s-2c a t a l y t i ca c t i v i katalkats-1·molyCertain units that are not part of the SI are essential and used so widely that they are accepted by the CIPM (Commission Internationale des Poids Et Mesures) for use with the SI. Some commonly used units are given in Table 1.4.Table 1.4 Non-SI units accepted for use with theSIN a m e SymbolQuantityEquivalentSIunitmi n u t e mintime1min=6sho u r htime1h6min=36s da y dtime1d=24h=144min=864sdegreeo fa r c °planeangle1°=(π/18)radm i n u t eo fa r c ′planeangle1′=(1/6)°=(π/18radsecondo fa r c ″planeangle1″=(1/6)′=(1/36)°=(π/648)rdhect a r e haarea1ha=1a=1m²l i t r e lorLvolume1l=1dm3=.1m3ton n e tmass1t=13kg=1MgThe 20 SI prefixes used to form decimal multiples and submultiples of SI units are given in Table 1.5.Table 1.5 SI PrefixesF a c t o r NameSymbolFactorNameSymbol1 0 24yottaY 1-1decid1 0 21zettZ 1-2centc。
化学专业英语的课件
4
However , it is useful from the outset to know something about how to form their names .
outset [‘autset] n. 开始；开端
• 然而 从一开始就知道一些关 然而, 于它们的名字是如何形成的是 很有用的。 很有用的。
systematic [,sisti'mætik] adj. 有系统的；系统的； 体系的；分类的 reveals [ri'vi:l] n. 暴露 vt. 揭示 Elements [‘elimənts] n. 基 础；原理 要素 元素成份 元件 自然环境 atoms ['ætəm] n. 原子 arranged [ə'reindʒd] adj. 安排的v. 安排；计划；准 备
The systematic naming of compounds,which is called chemical nomenclature ,follows a set of rules ,so that the name of each compound need not be memorized ,only the rules.
• compositions [,kɔmpə'ziʃə ʃənz] ɔ ʃə n. 组成成分；作 组成成分； 品辑； 品辑；艺术作品
• 许多化合物在他们组 成已知之前给予通俗 的名字。 的名字。
6
Common names include water ,salt ,sugar , ammonia ,and quartz.
• 无机物质 •的命名 的命名
3
You will meet many compounds in this text and will learn their names as you go along .
有机化学英文课件chapter7
M a c in to s h P IC T im a g e fo rm a t
is n o t s u p p o rte d
is n o t su p p o rted
7-5
Acidity
The pKa of acetylene and terminal alkynes is approximately 25, which makes them stronger acids than ammonia but weaker acids than alcohols (Section 4.1)
M a c in to s h P IC T im a g e fo rm a t
is n o t s u p p o rte d
7-16
Addition of HX
Alkynes undergo regioselective addition of either
1 or 2 moles of HX, depending on the ratios in
M a c in to s h P IC T im a g e fo r m a t
is n o t s u p p o r te d
7-7
Alkylation of Alkyne Anions
Alkyne anions are both strong bases and good nucleophiles
7-2
Nomenclature
IUPAC: use the infix -yn- to show the presence of a carbon-carbon triple bond
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厦门大学固体表面物理化学国家重点实验室
• Carbon can form straight chains, -C-C-C-C-C-C-C-C-C-C-
as well as branched chains and ring structures. • In addition carbon atoms can form double and triple bonds with other carbon atoms or with nonmetals, C=C CC C=O CN • The nonmetallic elements that appear most often in organic compounds are O,N,S,P, the halogens(卤素) and H, an element which is present in almost all organic compounds. • The hydrocarbons are organic compounds consisting of only two elements, C and H.
• In the electron dot structure for methane, nd must form four single bonds with the four H atoms.
H H CH
H
State Key Laboratory for Physical Chemistry of Solid Surfaces
• Because of the structural isomerism the molecular formula is not the best way to represent an organic compound. Structural formulas which indicate how the atoms are connected to each other are necessary.
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10.5 Structural Isomerism(结构异构)
• Structural Isomers (异构体) are two or more compounds which have the same molecular formula but a different arrangement of atoms.
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10.6 Structural Isomers of Alkanes
• All alkanes that have more than three C atoms have at least two structural isomers.
• In Wöhler’s landmark experiment, urea, a component of urine, was produced in a laboratory vessel(器皿) instead of the bladder(膀胱) of an animal. This was the first time that an organic compound had been synthesized in the laboratory without the assistance of any vital force. A new era of chemistry thus began.
厦门大学固体表面物理化学国家重点实验室
• In fact, before the year 1825 no scientist had ever been able to synthesize an organic compound starting with one or more inorganic compounds.
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10.2 Uniqueness of Carbon
• The reason that there are so many possible organic compounds is that the carbon atom has unique bonding characteristics, being able to form long chains by bonding other carbon atoms. • Formation of chains is called catenation(连锁). • Some other group IV elements can also form chains, although they are very short and much less stable than carbon chains. Silicon, for instance, can form chains as long as six atoms, but carbon has an unlimited capacity to undergo catenation.
• The arrangement of atoms is represented by a formula called the structural formula.
• Thus Structural isomers have the same molecular formulas but different structural formulas.
• Some of the organic carbon compounds that we have discussed are methane, ethene, acetylene, acetic acid and citric acid; these represent only a few of the 3 million organic compounds known.
Chemistry English
Lecture 7
State Key Laboratory for Physical Chemistry of Solid Surfaces
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Chapter 10 Alkanes
10.1 Introduction
• In this chapter we begin our study of organic chemistry, a subject which is most often defined as the chemistry of the compounds of chemistry.
• In that year, a German chemist, Friedrich Wöhler (1800-1882), obtained an organic compound, urea(尿 素), by heating an inorganic compound, ammonium cyanate (氰酸铵). NH4NCO (NH2)2CO
• The term “organic” was chosen because scientist thought that organic compounds could be derived from organic matter (plants and animals) only.
State Key Laboratory for Physical Chemistry of Solid Surfaces
• All alkanes share the same general formula:
CnH2n+2 • The name which corresponds to each alkane
formula includes a prefix followed by the ending ane. The prefixes for the first four alkanes are meth-, eth-, prop-, and but-. The prefixes for the net six alkanes correspond to the roots of the Greek words for the numbers 5 to 10 and are thus easier to remember. (pent-, hex-, hept, oct, non-,and dec-)
State Key Laboratory for Physical Chemistry of Solid Surfaces
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10.3 Alkanes: General Formula
• Alkanes are hydrocarbons which contain only single bonds between any two C atoms.
• Both methane (CH4) and ethane (C2H6) has one structural isomer.
• There is only a single structural isomer for propane (C3H8).
• Butane, C4H10, is the first member of the alkane series to have more than one structural isomer. There are two different ways to arrange the 4 C atoms and the 10 H atoms in butane.