化学专业英语《Chemistry English》课程教学资源（PPT课件）Lecture 01

Outline of the Course1. Some Aspects of General Chemistry(~ 7 times)2. Some Aspects ofInorganic Chemistry(~ 4 times)3. Some Aspects of Organic Chemistry(~3times)4. How to write a scientific paper

2 Outline of the Course 1. Some Aspects of General Chemistry (~ 7 times) 2. Some Aspects of Inorganic Chemistry ( ~ 4 times) 3. Some Aspects of Organic Chemistry ( ~3 times) 4. How to write a scientific paper

Chemistry EnglishInorganicChemistryChemicalPrinciplesAnalyticalChemistryOrganicChemistryPhysicalChemistryStructuralChemistry(QuantumChemistry&Crystallography)Polymer ChemistryBiochemistry4

4 Chemistry English Inorganic Chemistry Chemical Principles Organic Chemistry Analytical Chemistry Physical Chemistry Structural Chemistry (Quantum Chemistry & Crystallography) Polymer Chemistry Biochemistry

Chemical CalculationsQuantitative chemistryis about chemicaleguations andwhat they tell you in terms of the amounts of reactants usedup and products madeintermsof:as regardsuse up: consumeQualitative→ Quantitative5

5 Chemical Calculations Quantitative chemistry is about chemical equations and what they tell you in terms of the amounts of reactants used up and products made in terms of: as regards use up: consume Qualitative Quantitative

Chemical CalculationsCHEMCAL CHANGEChemical changes have three main features:1. New substances are made2. There is an energy change between the reacting system andits surroundings3. There is a fixed relationship between the masses of thereactants and products-this is called the stoichiometry ofthereactionStoichiometry is the name given to the property ofpure substances to react together in whole numberratios of particles.Chemical changes are nearly always written asequations showing the reactants and productssymbolically in the form of some kind of formula.6

6 Chemical Calculations CHEMICAL CHANGE Chemical changes have three main features: 1. New substances are made 2. There is an energy change between the reacting system and its surroundings 3. There is a fixed relationship between the masses of the reactants and products-this is called the stoichiometry of the reaction Stoichiometry is the name given to the property of pure substances to react together in whole number ratios of particles. Chemical changes are nearly always written as equations showing the reactants and products symbolically in the form of some kind of formula

Chemical CalculationsDIEEERENTKINDSOFFORMULAEmpirical formula shows the simplest whole numberratio of atoms in the particles of the substance, e.g. C,H.Oand CH.Molecular formula shows the actual number of atomsin a particle of the substance, e.g. C,H,O and C,H2Structural formula shows the arrangement of atoms intheparticleEither written as, e.g. CH,CH,OH and HCCHOr drawn asHHHH-C=CH?HHSome people call the drawn formulas displayedformulas, but this is not common.7

7 Chemical Calculations DIFFERENT KINDS OF FORMULA Empirical formula shows the simplest whole number ratio of atoms in the particles of the substance, e.g. C2H6O and CH. Molecular formula shows the actual number of atoms in a particle of the substance, e.g. C2H6O and C2H2 . Structural formula shows the arrangement of atoms in the particle Either written as, e.g. CH3CH2OH and HCCH Or drawn as Some people call the drawn formulas displayed formulas, but this is not common

Chemical CalculationsHCI(ag) + Na OH(ag)CHEMICAL EOUATIONSH20()+NaCI(ag)Reactants are normally written on the leftProducts are normally written on the rightThe arrow -→between them means reacts togive and sometimes has the conditions writtenabove orbelow itheatCuO + CO,CuCO3There are two different kinds of eguation and although they are oftenused interchangeably, they really have different uses depending onwhich feature of the reaction is being studied8

8 Chemical Calculations CHEMICAL EQUATIONS • Reactants are normally written on the left. • Products are normally written on the right. • The arrow →between them means reacts to give and sometimes has the conditions written above or below it. CuCO3 CuO + CO2 heat There are two different kinds of equation and although they are often used interchangeably, they really have different uses depending on which feature of the reaction is being studied

Chemical CalculationsIONICEOUATIONSThese are used when we think about how one lot ofsubstances is changed into another.They are connected with the bonding, structure, shape, orsize of the particles and themechanism of the reaction.When written particle equations state symbols are used, e.gCu2+(aq) + 20H-(aq)→ Cu(OH)2(s)This equation tells us that a copper aquo ion reacts withhydroxide ions to make an insoluble product.9

9 Chemical Calculations IONIC EQUATIONS These are used when we think about how one lot of substances is changed into another. They are connected with the bonding, structure, shape, or size of the particles and the mechanism of the reaction. When written particle equations state symbols are used, e.g. This equation tells us that a copper aquo ion reacts with hydroxide ions to make an insoluble product. Cu2+(aq) + 2OH- (aq) Cu(OH)2 (s)

Chemical CalculationsHCI(aq) + Na OH(ag)H20()+Nacl(ag)FULLEOUATIONSThese are used when the stoichiometry of thereactions is being studied. They are connectedwith the relative amounts of the reactants usedand products madeState symbols are usually not essential here, although greater creditis given for their usee.g.2Mg+O2 → MgOThis equation tells us that 2 moles of magnesium react with 1mole of oxygen molecules to make 1 mole of magnesium oxide-

10 Chemical Calculations FULL EQUATIONS These are used when the stoichiometry of the reactions is being studied. They are connected with the relative amounts of the reactants used and products made. State symbols are usually not essential here, although greater credit is given for their use e.g. This equation tells us that 2 moles of magnesium react with 1 mole of oxygen molecules to make 1 mole of magnesium oxide. 2Mg + O2 MgO

Chemical CalculationsWordsWordsquantitativein terms ofsurroundings: environmentrelationship: relationship between A&Bstoichiometry, stoichiometricsymbolically, symbol, symbolicformula: formulas. formulaeaquo: copper aquo ionaqueoushydroxide: hydrogen + oxidee.g.: Latin exempli gratia = for examplei.e.: Latin id est = that isviz.: Latin videlicet = namelyca.: Latin circa = about11

11 Chemical Calculations Words quantitative in terms of surroundings: environment relationship: relationship between A&B stoichiometry, stoichiometric symbolically, symbol, symbolic formula: formulas, formulae aquo: copper aquo ion aqueous hydroxide: hydrogen + oxide e.g.: Latin exempli gratia = for example i.e.: Latin id est = that is viz.: Latin videlicet = namely ca.: Latin circa = about Words

Calculations from equationsThe mole is the unit in which amounts of substance are measuredin chemistry.The mole is defined as that amount of substance that contains thesame number of particles as there are atoms in exactly 12 g of theisotope carbon 12The number of particles in a mole is found to be 6.02 X 1023: thisnumber is called the avogadro constant and has the symbol L1023 :ten power twenty three12

12 Calculations from equations The mole is the unit in which amounts of substance are measured in chemistry. The mole is defined as that amount of substance that contains the same number of particles as there are atoms in exactly 12 g of the isotope carbon 12. The number of particles in a mole is found to be 6.02×1023: this number is called the avogadro constant and has the symbol L. 1023 : ten power twenty three