Basic Chemistry 基础化学 主讲人：Xiuli Dong 董秀丽 副教授 Office：实验楼B楼 213 董秀丽 副教授 Office：实验楼B楼 213 Tel：6913464 QQ: 850961018

Course Teachers Xiuli Dong 董秀丽 (15h, 3 weeks ) Wei Hu 胡威 (15h, 3 weeks ) Xiaoyan Wang 王晓艳 (10h, 2 weeks ) Yuling Huang 黄玉玲 (10h, 2 weeks ) Huaibin Zhang 张怀斌 (10h, 2 weeks )

Notices Language: English and Chinese Question anytime and anywhere Method: memorize based on understanding Notice: focal points Exercises:

1. the Textbook

2. the main contents Atomic Structure Molecular Structure Osmotic Pressure of Solutions Rates and Mechanisms of Chemical Reactions Basic chemistry Electrolyte Solutions Organic chemistry Buffer Solutions Coordination Complexes

3. Course Schedule for Basic Chemistry

Chapter 1 Introduction 1.1 Introduce to Chemistry 1.2 Measurement and SI Units 1.3 Ways of Expressing Concentration 1.4 Names and Symbols of the Elements 1.5 Nomenclature Inorganic Compounds Key points: Express the concentration of a solution in several different ways (such as molarity, molality, mole fraction )

1.1 Introduce to Chemistry 1.1.1 What is chemistry? Term: The dictionary defines chemistry as "the science of the composition, structure, properties, and reactions of matter, especially of atomic and molecular systems." Chemistry is the study of matter and its interactions with other matter and with energy.

2. Why do we study chemistry? Every material thing is a chemical or a mixture of chemicals. Chemistry is central to all branches of science. Specialized steels in bicycles Liquid crystals in computer screens High-tension polymers in synthetic hip joints

Ronald Breslow: Chemistry Today and Tomorrow—The Central, Useful, and Creative Science Considering the importance of chemistry for understanding life, and the importance of medicinal chemistry for health, it is no surprise that the normal education of physicians involves a lot of chemistry. … Modern doctors need to prepare for a future in which chemistry plays an even larger role in human health. R. Breslow is Professor of Chemistry at Columbia University and the President of the American Chemical Society.

1.4 Names and Symbols of the Elements

1.2 Names and Symbols of the Elements (Periods 1 and 2) Hydrogen H 1.00794 Helium He 4.002602 Lithium Li 6.941 Beryllium Be 9.012182 Boron B 10.811 Carbon C 12.011 Nitrogen N 14.00674 Oxygen O 15.9994 Fluorine F 18.9084032 Neon Ne 20.1797

(Periods 3) Sodium Na 22.989768 Magnesium Mg 24.3050 Aluminum Al 26.98l539 Silicon Si 28.0855 Phosphorus P 30.973762 Sulfur S 32.066 Chlorine Cl 35.4527 Argon Ar 39.948

(Periods 4) Potassium K 39.0983 Calcium Ca 40.078 Scandium Sc 44.955910 Titanium Ti 47.88 Vanadium V 50.9415 Chromium Cr 51.9961 Manganese Mn 54.93805 Iron Fe 55.845 Cobalt Co 58.93320 Nickel Ni 58.6934

(Periods 4 (continued)) Copper Cu 63.546 Zinc Zn 65.39 Gallium Ga 69.723 Germanium Ge 72.61 Arsenic As 74.92l59 Selenium Se 78.96 Bromine Br 79.904 Krypton Kr 83.80

1.3 SI units Units are standards that are used for quantitative comparison between measurements for the same type of quantity. The first measurements were probably based on the human body. In 17th and 18th centuries, scientists found that the lack of standard units was a problem.

Our current system of measurement, the metric system, began in 1790 when the National Assembly of France set up a committee to establish consistent unit standards. In 1960, another international committee met in France to establish the International System of Units, a revised metric system now accepted by scientists throughout the world. The units of this system are called SI units, from the French Système International d'Unités.

The SI system is based on a set of 7 fundamental units, or base units, each of which is identified with a physical quantity. All other units, called derived units, are combinations of these seven base units. For example, the unit for speed, meters per second (m/s), is the unit for length (m) divided by the unit for time (s). For quantities that are much smaller or much larger than the base unit, we use decimal prefixes and scientific notation (A×10n ).

1.3.1 SI Base Units and SI Prefixes Table 1 SI Base Units Quantity Unit Symbol Chinese Length meter m 米 Mass kilogram kg 千克 Time second s 秒 Temperature kelvin K 开尔文 Amount of substance mole mol 摩尔 Electric current ampere A 安培 Luminous intensity candela cd 坎德拉

1.3.2 SI Base Units and SI Prefixes Table 2 SI Prefixes Multiple Prefix Symbol 1018 exa E 10-1 deci d 1015 peta P 10-2 centi c 1012 tera T 10-3 milli m 109 giga G 10-6 micro μ 106 mega M 10-9 nano n 103 kilo k 10-12 pico p 102 hecto h 10-15 femto f 10 deka da 10-18 atto a For example: km、m、dm、cm、mm、μm、nm； s、ps、fs 千米、米、分米、厘米、毫米、微米、纳米；秒、皮米、飞米

1.3.3 Some Important SI Units in Chemistry Length and Mass The meter (m) is the SI base unit of length. By combining it with one of the SI prefixes, you can get a unit of appropriate for any length measurement. the nanometer (nm): 1nm=10–9m The kilogram (kg) is the SI base unit of mass. In forming other SI mass units, prefixes are added to the word gram (g) to give units such as the milligram (1mg=10 –3g).

Volume (derived unit): Volume is the space that a given quantity of matter occupies. The SI unit for volume is the cubic meter (m3). Since this is a rather large volume for typical laboratory situations, the metric unit, known as the liter, is used. One liter is defined as the exact volume of one cubic decimeter (i.e. 1 L = 1 dm3 = 10 –3 m3). On a smaller scale, one milliliter is the exact volume of one cubic centimeter (1 mL = 1 cm3 = 1 cc = 10 –6 m3).

Temperature (derived unit): The Celsius scale is defined by assigning the freezing point of water a value of 0℃ and the boiling point of water as 100℃. （摄氏温度） The relationship between Celsius and Kelvin temperature is TK= TC + 273.15 T = t + 273.15 开尔文温度 = 摄氏温度 + 273.15

New Words solution 溶液 solute 溶质 solvent 溶剂 dissolve 溶解 dilute 稀的 concentrated 浓的 concentration 浓度 mole 摩尔 liter 升 milliliter 毫升 molar mass 摩尔质量 amount of substance 物质的量 molarity 物质的量浓度 molality 质量摩尔浓度 mole fraction 摩尔分数

1.4 Ways of expressing concentration （溶液的组成标度） The concentration of a solute is the amount of solute dissolved in a given quantity of solvent or solution. The quantity of solvent or solution can be expressed in terms of volume or in terms of mass or molar amount. Thus, there are several ways of expressing the concentration of a solution, such as molarity, molality and mole fraction.

1.4.1 The Mole Concept 1.4.1.1 mol（摩尔） Definition: The mole is the SI unit for amount of substance. It is defined as the quantity of a given substance that contains as many entities (molecules or formula units) as the number of atoms in exactly 12 g of carbon-12. This number is called Avogadro’s number and has a value of 6.02×1023 units/mol. 1 mol=12g of 12C=6.02×1023 units

1 mol H2 contains 6.02×1023 H2 molecules. Notice: When using the term mole, it is important to specify the formula of unit to avoid any misunderstanding. For example, 1 mol H contains 6.02×1023 H atoms. 1 mol H+ contains 6.02×1023 H ions. 1 mol H2 contains 6.02×1023 H2 molecules. 1 mol H2 ---------- 2 mol H 1 mol H2SO4 ---------- 2 mol H+ ---------- 1 mol SO42-

Problems What’s the relationsship between the number of the moles and the weight ? For example, 98 grams of H2SO4 is equivalent to one mole of H2SO4, we can write the following relationship: 49 grams of H2SO4 is equivalent to 0.5 mole of H2SO4, we can write the following relationship:

Molar mass = Formula weight Definition: The molar mass of any substance is the mass (in gram) of one mole of that substance. mass kg, g MB def mB/ nB Molar mass kg•mol-1, g•mol-1 Mole mol Conclusion: For all substances, the molar mass in grams per mole equal to the formula weight in atomic mass grams. Molar mass = Formula weight

nNaOH mNaOH/MNaOH Interconverting Moles and Mass: Example 1 Conversion of Mass to Mole (a)How many moles of NaOH are present in 80g? (b)How many moles of O2 are present in 16g? (c)How many moles of O are present in 16g? Procedure Write down what you have been given. Find the molar mass (molecular weight ) of the molecule. Calculate the moles of the molecule. nNaOH mNaOH/MNaOH 80 / 40 2 mol

1.4.2 Molarity- Molar Concentration (摩尔浓度，物质的量浓度) Definition: The molarity of a solution is the moles of solute in a liter of solution. Mole of the sulute, mol Molarity mol•m-3, mol•L-1, mmol•L-1,μmol•L-1 cB def nB/ V Volume of the sulution m3, L c(C6H12O6) = 3.9 mmol•L-1 ~ 5.6 mmol•L-1

nNaCl mNaCl/MNaCl cNaCl nNaCl/V Example2 Calculating Molarity of a Solution What is the molarity of a solution prepared by dissolved 4.5 g of NaCl in enough water to form 500 mL of solution? Procedure Write down the formula for molarity and what you have been given. Convert the mass of solute to moles of solute by using the molar mass. Calculate the molarity. nNaCl mNaCl/MNaCl 4.5 / 58.5 0.077 mol cNaCl nNaCl/V 0.077 / 0.500 0.154 mol•L-1

cd cc·Vc / Vd Dilution of Concentrated Solution When a solution is diluted, the volume is increased by adding more solvent and the concentration is decreased, but the total amount of solute is constant. cc·Vc = cd ·Vd = n Example 3 Calculation of Molarity of a Dilute Solution What is the molarity of a solution of KCl that is prepared by dilution of 855 mL of a 0.475 mol•L-1 solution to a volume of 1.25 L? cd cc·Vc / Vd 0.475*0.855 / 1.25 0.325 mol•L-1

Conversion of Mass Percent of Solute to Molarity Example 4 Calculation of Molarity from Mass Percent Concentrated laboratory acid is 35.0% by mass HC1 and has a density of 1.18 g/mL. What is its molarity? Conclusion:

Procedure You can get mass of solute in 100 g of solution using definition of mass percent. Convert the mass of solution to volume of solution by using the density. Convert the mass of solute to moles of solute by using the molar mass. Write down the formula for molarity and what you have been given. Calculate the molarity.

Chapter 2 Colligative Properties of Solutions(稀溶液的依数性) Introduction Injection of a hypertonic solution into the blood stream will cause crenation, while a hypotonic solution will cause hemolysis. Why? Solution Concentration Vapor pressure lowering Colligative properties Boiling point elevation Freezing point depression Osmosis and osmotic pressure

Key points: To relate the osmosis and osmotic pressure to the concentrations of solution To calculate osmotic pressure of electrolytes and nonelectrolytes To understand the importance of osmosis in medicine

New Words osmolarity 渗透浓度 electrolyte 电解质 isotonic 等渗的 hypotonic 低渗的 hypertonic 高渗的 hemolysis 溶血 electrolyte 电解质 nonelectrolyte 非电解质 osmosis 渗透 osmotic pressure 渗透压 semipermeable membrane半透膜

2.4 Osmosis and Osmotic Pressure of Solutions （溶液的渗透与渗透压） Case 1 Isotonic solution Surrounding sol’n at 9 g/L NaCl Red blood cells normal. Case 2 Hypotonic solution Surrounding sol’n less than 9g/L NaCl Red blood cells rupture. Hemolysis Case 3 Hypertonic solution Surrounding sol’n more than 9g/L NaCl Red blood cells shrivel. Crenation

Problems What’s the Osmosis and Osmotic Pressure? 2.4.1 Osmosis （渗透） Experiment: On the left is a pure solvent, and on the right, a solution. The two are separated by a semipermeable membrane. As a result, the water level rises on the right and drops on the left.

Term: Semipermeable membrane -Certain membranes allow solvent molecules to pass through them but not solute molecules. Osmosis -When a solution and its pure solvent are separated by a semi-permeable membrane, the pure solvent will diffuse through the membrane and dilute the solution. This process is known as osmosis.

Problems Why? Solvent molecules can pass through the membrane in both directions, but the concentration of water is larger in the pure water, more water molecules strike the membrane per second on that side, and more water moves into the solution than leaves it.

Problems If a solution of lower C and a solution of higher C are separated by a semi-permeable membrane, will there be the osmosis? Why? Concentrated solution Dilute solution Semipermeable membrane

Problems Problems Condition ? Direction ? a semipermeable membrane Concentrated solution Dilute solution Semipermeable membrane a semipermeable membrane solutions of different C on either side of the membrane Problems Direction ? from a solvent system to a solution system from the solution of lower C to the solution of higher C

2.4.2 Osmotic pressure（渗透压） Term: The amount of pressure that must be exerted just to prevent net transport of solvent across a semipermeable membrane is the osmotic pressure. Symbol: π Unit:Pa (kPa)

Problems How to calculate the osmotic pressure ? Π = cB RT Van’t Hoff equation： the gas constant 8.314 J • K-1 • mol-1 the absolute temperature, K Osmotic pressure kPa Π = cB RT Molarity of solutions mol• L-1

1:1 NaCl→ Na++Cl- total m = 2 cB 1:2 CaCl2→ Ca2++ 2Cl- total m = 3 cB Attention: cB is the total molarity of all the dissociated solute species present. Nonelectrolyte(非电解质): total molarity =cB Electrolyte (电解质): total molarity = i cB 1:1 NaCl→ Na++Cl- total m = 2 cB 1:2 CaCl2→ Ca2++ 2Cl- total m = 3 cB

Nonelectrolyte (非电解质) Example1 When 2.00 g of sucrose (蔗糖，C12H22O11) is dissolved in 50.0 mL of water solution, what is the osmotic pressure at 37℃? 解：

Π ＝ i cBRT Electrolyte (电解质): Π ＝ i cBRT Example 2 The 9.0 g ·L-1 salt (NaCl) solution is called physiological saline. What is the osmotic pressure at 37℃? 解： Π ＝ i cBRT

The red blood cells in different molarity solutions 2.4.3 Importance of Osmosis (osmotic pressure) in medicine Why？ physiological saline Less than 9 g/L more than 9 g/L The red blood cells in different molarity solutions

cos nos/ V 2.4.3.1 Osmolarity(渗透浓度) Term: osmotically active substances（渗透活性物质）：In body fluids, there are ions, small molecules, and large molecules. All these substances have an osmotic effect. osmolarity -the total molarity of osmotically active substances cos def nos/ V

cos def nos/ V Example 3 What is the osmolarity of (1) 50.0 g ·L-1 glucose (C6H12O6) solution and (2) 9.0 g ·L-1 salt (NaCl) solution ?

Example 4 The 0. 4 mol. L-1 glucose (C6H12O6) solution 1L and 0. 2 mol Example 4 The 0.4 mol.L-1 glucose (C6H12O6) solution 1L and 0.2 mol.L-1 salt (NaCl) solution 1L are mixed with each other. What is the osmolarity of the final solution?

2.4.3.2 isotonic, hypertonic and hypotonic sulutions Standard: blood plasma hypotonic isotonic hypertonic 280 mmol.Ｌ-1 320 mmol.Ｌ-1 Terms: Isotonic: two solutions with the same  separated by a semipermeable membrane. Hypertonic: having a higher osmotic pressure Hypotonic: a solution of lower  than a isotonic solution.

Isotonic solution: 0.9% (9g/L) NaCl Red blood cells: osmolarity = 0.306mol/L 0.9% (9g/L) NaCl osmolarity = 2×9g/L /58.5g/mol =0.306mol/L Red blood cells normal.

Hypotonic solution: 0.5% (5g/L) NaCl Red blood cells: osmolarity = 0.306mol/L 5g/L NaCl: osmolarity = 0.171mol/L Hemolysis (溶血): red blood cells placed in a hypotonic solution (relative to intracellular solution); there is a higher solute concentration in the cell; osmosis occurs and water moves into the cell. The cell bursts.

Hypertonic solution: 1.5% (15g/L) NaCl Red blood cells: osmolarity = 0.306mol/L 15g/L NaCl: osmolarity = 0.513mol/L Crenation（血栓）: red blood cells placed in hypertonic solution (relative to intracellular solution); there is a lower solute concentration in the cell than the surrounding tissue; osmosis occurs and water passes through the membrane out of the cell. The cell shrivels up.

Conclusion: For intravenous feeding, it is necessary that the nutrient solution have exactly the osmotic pressure of blood plasma. If it does not, the blood cells may collapse or burst as a result of osmosis. To prevent crenation or hemolysis, solutions must be isotonic. Range of Isotonic Solution: 280 ~ 320 mmol·L-1 Isotonic Solution: physiological saline solution (9g/L NaCl), 50g/L glucose Standard: blood plasma

Problems Examples of osmosis? Limp carrot placed in water becomes firm because water enters via osmosis. Salty food causes retention of water and swelling of tissues (edema). Water moves into plants through osmosis. Salt added to meat or sugar to fruit prevents bacterial infection (a bacterium placed on the salt will lose water through osmosis and die) Cucumber placed in NaCl solution loses water to shrivel up and become a pickle.

Conclusions cB nB/ V Π = i cB RT 【key points】 1. Molarity- Molar Concentration (摩尔浓度，物质的量浓度) 2. Osmosis and Osmotic Pressure （渗透与渗透压） 3. isotonic, hypertonic and hypotonic sulutions 【homework】 p20 T2，T4 p39 T6，T9 cB def nB/ V Π = i cB RT