《基础化学》英文教学课件：Chapter-1-1

1、E-mail: g_General Chemistry王锦芝汕头大学医学院化学教研室Some Requirements and Suggestions1. Bring yourself to class. 2. Be awake and follow me.3. Prepare for the lessons (basic chemical expressions).4. Work on the problems and exercises after the class (homework).Basics of ChemistryAn Introduction to Chemistry1.

2、Atomic structure2. Chemical substances: Formulas and namesAtoms, Molecules, and IonsPhysical MeasurementsCalculation with Chemical Formulas and Equations1. Mass and moles of substance2. Chemical reactions: Equations3. Stoichiometry: Quantitative relations in chemical reactions4. Working with solutio

3、nsChapter 1_1An Introduction to ChemistryAn Introduction to ChemistryI. Modern chemistry1. What is chemistry ?Chemistrythe subject you are going to learnis the science of matter and the changes it can undergo.The world of chemistry therefore embraces everything around usthe building we live in, the

4、food we eat, the flesh we are made of, and the silicon we build into computer. There is nothing materials outside the reach of chemistry, be it living or dead, vegetable or mineral, on Earth or in a distant star.6.An Introduction to ChemistryfieldElectric fieldMagnetic fieldAn Introduction to Chemis

5、try2. Chemistry: A science at two levelsChemistry operates on two levels. At one level, chemistry is about matter and its transformations. At this level, we can actually see the changes, as when a fuel burns, a leafchanges color in the fall, or magnesium burns brightly in air. This level is the macr

6、oscopic (宏观的) level, the level dealing with the properties of large, visible objects. An Introduction to ChemistryHowever, there is underworld of change, a world that we cannot see directly. At this deeper microscopic (微观的) level, chemistry interprets these phenomena in terms of the rearrangements o

7、f atoms.An Introduction to ChemistryThe symbolic language of chemistry, the expression of chemical phenomena in terms of chemical symbols and mathematical equations, ties the two levels together. Chemical equations describe events at the macroscopic level in a way that can be interpreted atthe micro

8、scopic level. It has been said that a chemist thinks at the microscopic level, conducts experiments at the macroscopic level, and represents both symbolically. An Introduction to ChemistryExperiment and explanation are the heart of chemical research. An experiment (实验) is an observation of natural p

9、henomena carried out in a controlled manner so that the results can be duplicated (reproduced?) and rational conclusions obtained.3. Experiments and ExplanationAfter a series of experiments, perhaps a researcher sees some relationship or regularity in the results. If the regularity is fundamental an

10、d we can state it simply, we call it a law. A law (定律) is a concise statement or mathematical equation about a fundamental relationship or regularity of nature. An Introduction to ChemistryAt some point in a research project, a scientist tries to make sense of the results by devising an explanation.

11、 A hypothesis (假定) is a tentative explanation of some regularity of nature.If a hypothesis successfully passes many tests, it becomes known as a theory. A theory (理论) is a tested explanation of basic natural phenomena.The general process of advancing scientific knowledge through observation; the fra

12、ming of laws, hypothesis, or theories; and the conducting of more experiments is call the scientific method.An Introduction to ChemistryExperimentsResultsHypothesisFurther experimentsdevised based on hypothesisPositive results support hypothesisNegative results lead to modification or rejection of h

13、ypothesis and formulation of new hypothesisA theory follows after results consistently support a hypothesisFurther experimentsCisplatinthe first member of a class of platinum-containing anti-cancer drugs An Introduction to Chemistry4. The different branches of chemistryFour main traditional branches

14、 are:Inorganic chemistry (无机化学): All the other elements and their compounds.Organic chemistry (有机化学): Compounds of carbon.Physical chemistry (物理化学): The principle of chemistry.Analytical chemistry (分析化学): Techniques for identifying substances and measuring their amounts.More branches of chemistry ar

15、e:Biochemistry (生物化学): Biologically important substances, processes, and reactions. Theoretical chemistry (理论化学): Molecular structure and properties in terms of mathematical models.Chemical engineering (化学工程): Industrial chemical processes.An Introduction to Chemistry5. Contents of this courseIntrod

16、uction: Chapter 1SolutionChapter 2: Colligative properties of solutionChapter 3: Electrolyte solutionChapter 4: BufferChapter 5: ColloidsBasic principlesChapter 6: ThermodynamicsChapter 7: KineticsChapter 8: ElectrochemistryStructural chemistryChapter 9: Atomic structure and periodic table of the el

17、ementChapter 10: Covalent bond and intermolecular forcesChapter 11: Coordination compoundAn Introduction to ChemistryAnalytical chemistryChapter 12: Titration analysis (chemical analysis)Chapter 13: UV-Vis spectrophotometry (instrumental analysis) An Introduction to ChemistryII. Law of conservation

18、of mass（质量守恒定律）Mass: The quantity of matter in a material. The mass is measured by a balance. Law of conservation of mass: The total mass remains constant during a chemical reaction.Antoine Lavoisier (17431794)Heated mercury() oxideAn Introduction to ChemistryIII. Matter: Physical state and chemical

19、 constitutionTwo principal ways to classify matter: By its physical state: Solid, liquid, or gas; By its chemical constitution: Element, compound, or mixture.Classification of mattersAn Introduction to ChemistryThe main identifying characteristic of solids: Rigidity (Liquids and gases are fluids). W

20、hat distinguishes a gas from a liquid is the characteristic of compressibility (可压缩性). 1. Solids, liquids, and gasesMolecular representations of solid, liquid, and gas.SolidLiquidGasAn Introduction to ChemistrySolid: The form of matter characterized by rigidity; a solid is relatively incompressible

21、and has fixed shape and volume.The three forms of mattersolid, liquid, and gasare referred to as the states of matter.Liquid: The form of matter that is a relatively incompressible fluid; a liquid has a fixed volume but no fixed shape.Gas: The form of matter that is an easily compressible fluid; a g

22、iven quantity of gas will fit into a container of almost any size and shape.An Introduction to Chemistry2. Physical change and chemical changeA physical change is a change in the form of matter but not in its chemical identity. Changes of physical state are examples of physical changes.solidliquidga

23、sfreezingmeltingdepositionsublimationevaporationcondensationSublimation of I2Steam and liquid water are two different forms of the same chemical substance, water.CoffeineAn Introduction to Chemistry The process of dissolving one material in another is a further example of a physical change.An Introd

24、uction to ChemistryA chemical change (chemical reaction) is a change in which one or more kinds of matter are transformed into a new kind of matter or several kinds of matter.Na+Cl2 NaCl Linus Pauling(1901-1994)莱纳斯鲍林 Nobel Prize in Chemistry (1954)Nobel Peace Prize (1962)Sickle-Cell Anemia andHemogl

25、obin Solubility Hemoglobin is the substance in red blood cells that carries oxygen. Hemoglobin is normally present in solution within the red bloodcells. But in people with sickle-cell anemia, the unoxygenatedhemoglobin readily comes out of solution. It produces a fibrous precipitate that deforms th

26、e cell, giving it the characteristic sickle shape. Hemoglobins are large molecules (molecular weight about 64,000 amu) consisting of four protein chains, two of one kind ( chains) and two of another kind ( chains). Normal and sickle-cell hemoglobins are almost exactly alike, except that each chain o

27、f the hemoglobin responsible for sickle-cell anemia differs from normal hemoglobin in one place. In this place, the normal hemoglobin has the group which helps confer water solubility on the molecule because of the polarity of the group and its ability to form hydrogen bonds. The abnormal hemoglobin

28、 has the following hydrocarbon group:Hydrocarbon groups are nonpolar. This small change makes the molecule less water-soluble.How to Live Longer and Feel Better, advocated very high intake of Vitamin C.An Introduction to ChemistryA physical property is a characteristic that can be observed for a mat

29、erial without changing its chemical identity. Examples are physical state (solid, liquid, or gas), melting point, and color, etc.3. Physical property and chemical propertyA chemical property is a characteristic of a material involving its chemical change. A chemical property of sodium (Na) is its ab

30、ility to react with chlorine (Cl2) to produce table salt (NaCl).An Introduction to ChemistryA substance (纯物质) is a kind of matter that cannot be separated into other kinds of matter by any physical process. For example, water, Na, Cl2, NaCl.No matter what is its source, a substance always has the sa

31、me characteristic properties.For example, whether NaCl is obtained by burning sodium in chlorine or from seawater(41018 tons), it is a white solid melting at 801 C.Substance: element or compound 4. Elements, compounds, and mixturesA substance is a single, pure form of matter. An Introduction to Chem

32、istryAn element (单质) is a substance that cannot be decomposed by any chemical reaction into simpler substances. For example, Na, Cl2.(An element is a substance composed of only one kind of atom.)A compound (化合物) is a substance composed of two or more elements chemically combined in fixed proportions

33、. For example, NaCl, H2O.CDiamond graphiteO2O336.Householdaluminium foil AlYou are working in the office of a precious metals buyer. A miner brings you a nugget of metal that he claims is gold. You suspect that the metal is a form of “fools gold”, called pyrite, that is composed of iron and sulfur.

34、In the back of you office, you have a chunk of pure gold. What simple experiments coud you perform to determine whether the miners nugget is gold?Pyrite FeS2黄铁矿AuOrpiment, 雌黄As2S3 鸡冠石Realgar, 雄黄As4S4Arsenic trioxide ，砒霜As2O3Mr James Marsh (17941846) AsHgMERCURY水俣湾灾难Minamata DiseaseAn Introduction to

35、 ChemistryA mixture (混合物) is a kind of matter that can be separated by physical means into two or more substances. For example, NaCl solution.A mixture has variable composition;A mixture can be separated by physical process (e.g., distillation or magnet).Mixtures are classified into two types. A heterogeneous mixture（异相混合物） is a mixture that consists of physically distinct parts, each with different properties.A homogeneous mixture （均相混合物） (also known as a solution) is a mixture that is