2. General Chemistry M. R. Naimi-Jamal Faculty of Chemistry Iran University of Science & Technology

3. محمد رضا نعیمی‌ جمال شیمی‌ آلی ساعت رفع اشکال : شنبه ها و دوشنبه ها ۱ 1 - ۱ 0 مکان: طبقه اول دانشکده شیمی، اتاق 115 naimi@iust.ac.ir E-mail:naimi@iust.ac.ir

4. امتحان میان ترم 8 نمره 4 ۰ % امتحان پایان ترم ۱۲ نمره ۶۰ % کار کلاسی و تمرین 1 نمره - غیبت مجاز : ۳ / ۱۷ کل ساعت درسی ارزشیابی

5. فصل اول: مفاهیم اساسی‌

6. CHEMISTRY: is the study of the properties, composition, Chemistry is the study of the properties, composition, and structure of matter, the physical and chemical changes it undergoes, and the energy liberated or absorbed during those changes.

7. Why Study Chemistry? 1. To better understand the world: what it is made of and how it works. 2. Because it is the most practical and relevant of the sciences - chemistry is the study of EVERYTHING! 3. It is the “Central Science” - All other sciences intersect at and depend on chemistry. 4.It is essential to the national and local economies. 5.It is required for virtually every major involving Science, mathematics, or engineering. 6.And what reasons can you think of ?

8. Chemistry is an Observational Science Chemistry is an Observational Science ► Observation: Using the five senses to “see” what is and happens around you. ► Conclusion: An explanation of the cause or causes for one or more observations.

9. Observations vs. Conclusions OBSERVATION: When electricity is passed through a salt solution, a yellow-green gas and a colorless, flammable gas forms. CONCLUSION: The yellow-green gas is chlorine and the colorless gas is hydrogen.

10. The Scientific Method 1. Collect Facts or Data (Observe!!) 2. Search for Generalizations or Laws to Summarize the Facts. 3. Freely Use Your Imagination to Construct Theories or Models of Nature that Will Account for the Laws. 4.Test Theories/Hypotheses for Accuracy. 5.Modify Theories/Hypotheses as Necessary Based on Your Test Results.

11. فهرست ماده و انرژی واحد های بین المللی ‌SI عدم قطعیت و ارقام معنی‌ دار آنالیز ابعادی

12. انرژی ماده کائنات

13. طبقه بندی کائنات ماده (Matter) : فضا اشغال می‌ کند، جرم و اینرسی‌ دارد Energy انرژی (Energy): توانایی انجام کار یا تولید حرارت

14. ماده وانرژی رابطه اینشتین E = mc 2 جرم – انرژی

15. The Law of Conservation of Matter: Matter is neither created nor destroyed during a chemical reaction or a physical change. The Law of Conservation of Energy: Energy is neither created nor destroyed during a chemical reaction or a physical change. It can only be changed from one form into another. The Law of Conservation of Matter/Energy: The combined amount of matter and energy in the universe is constant. E = mc 2

16. حالات ماده گاز مایع جامد

17. حالات ماده Solid: has a rigid shape and a fixed volume that changes very little with temperature and pressure Liquid: like solids have a fixed volume but no definite shape (take on the shape of the container) Gas: no fixed volume - volume determined by the size of the container - the volume of a gas varies greatly with temperature and pressure

18. طبقه بندی مواد

19. Substance :(ماده خالص) A distinct type of matter. All samples of a substance have the same properties. Elements and compounds are substances. Mixture :(مخلوط) A sample of matter consisting of two or more substances which are NOT chemically combined.

20. Classification of Matter (Substances) Element: A substance that cannot be broken down (decomposed) into simpler substances by chemical reactions, e.g.: iron, gold, oxygen. Compound: A substance composed of two or more elements chemically combined in fixed ratios by mass. Water - H 2 O Carbon dioxide - CO 2 Sodium chloride - NaClIron(II) sulfide - FeS Substances:

21. Classification of Matter (Mixtures) Mixtures: F Homogeneous: Solutions” F Homogeneous: A mixture having only one phase; it is uniform (the same) throughout and has the same properties throughout. These are called „Solutions”. F Heterogeneous: NOT F Heterogeneous: A mixture with more than one phase. It is non-uniform and does NOT have the same properties throughout.

22. Matter and Change Phase - A sample of matter that is uniform in composition and physical state and is separated from other phases by a definite boundary.

23. Physical Change: A change in which each substance involved in the change retains its original identity and no new elements or compounds are formed. H 2 O (s) H 2 O (l) melting

24. Matter and Change Chemical Change: A change in which one or more elements or compounds (substances) are formed. “Reacting” 2 H 2 (g) + O 2 (g) 2 H 2 O (l) AgNO 3 (aq) + HCl(aq) AgCl(s) + HNO 3 (aq)

25. Chemical and physical change Chemical and physical change Chemical and physical change Chemical and physical change

26. جداسازی (Separation)

27. کروماتوگرافی (Chromatography) 1_17 حلال A BC مخلوط اجزائ مخلوط

28. Paper Chromatography Paper Chromatography Paper Chromatography Paper Chromatography

29. Measurement Chemistry is an Observational science. Chemistry is a Quantitative science. Measurement - A quantitative observation.

30. Measurement All measurements have three parts: 1. A value 26.9762 g 2. Units 3. An Uncertainty Examples: 33.2 mL72.36 mm 426 kg31 people

31. Measurement Conversion Factors: A fraction whose numerator and denominator contain the same quantity expressed in different units. 1 mile = 5280 ft 1 mile 5280 ft = 1 mile 1 = 1 1 cm = 0.01 m 1 cm 0.01 m = 1 cm 1 = 1 1 in = 2.54 cm 2.54 cm 1 in = 2.54 cm 1 = 1

32. Measurement Uncertainty in Measurements: Exact Measurements: Measured values determined by counting or when a value is defined. Examples: 31 people, 27 rocks, 2.54 cm = 1 in The uncertainty in these measurements = 0 Non-exact Measurements: All other measurements. The last digit recorded is uncertain; it is estimated!! Examples: 27.5 g, 32.7 mm12 467 km

33. Measurement Significant Figures: ارقام معنی‌دار Each digit obtained as a result of a measurement includes all of the certain digits and the first uncertain digit. The number of significant figures in a measurement is an indicator of the sensitivity of the measurement.

34. Measurement Rules for Significant Figures: 4 All non-zero digits are significant. 25.79 km27 mL 4 A zero between other significant figures is significant. 207.9 nm100.7 mL

35. Measurement 4 Initial zeros are NOT significant: 1 23 0.001 23 cm 3 4 Final zeros after the decimal point ARE significant: 23.100 23.100 ps 4 Final zeros in a measurement with no decimal point may or may not be significant. 32(might have 2, 3, or 4 significant figures!!) 3200 cm (might have 2, 3, or 4 significant figures!!) 4 Exact measurements have an infinite number of (They are CERTAIN!!) significant figures. (They are CERTAIN!!)

36. Measurement Number 6.29 g 0.00348 g 9.0 1.0  10 -8 100 eggs 100 g Count from left from first non-zero digit. Significant Figures 3 3 2 2 infinite bad notation

37. (Rounding Off) :گرد کردن Report to 3 significant figures: 10.235  12.4790  19.75  15.639  7.025  10.2 12.5 19.8 15.6 7.02 Note: 3rd digit is increased by one if 4th digit >5 and decreased to zero if 4th digit <5. If 4th digit is =5, 3rd digit is increased only if it is an odd number!

38. ارقام معنی‌دار: محاسبات ریاضی 13.4 Adding and subtracting: Use the number of decimal places in the number with the fewest decimal places. 11.676 + 1.14 + 0.6 13.416  35.2 mL + 0.34 mL = 35.54 mL = 35.5 mL 1.00794 u + 1.490 u + 15.9994 u = 18.49734 u = 18.497 u

39. ارقام معنی‌دار: محاسبات ریاضی Multiplying and dividing: Use the fewest significant figures. 0.01208  0.236 = 0.51186 = 5.12  10 - 3 (9.5760 g)/(12.2 mL) = 0.785 g/mL 5 3 4 3

40. واحدهای اندازه گیری SI نماد اختصارینام واحدکمیت فیزیکی Kgکیلوگرمجرم mمترطول sثانیهزمان Aآمپرجریان برق Kکلویندما cdشمعشدت درخشش molمولمقدار ماده

41. واحدهای اندازه گیری فرعی Derived Quantities ForceNewton N = kg m s -2 PressurePascal Pa = kg m -1 s -2 EenergyJoule J = kg m 2 s -2 Other Common Units LengthAngstrom Å = 10 -8 cm VolumeLitre L = 10 -3 m 3 EnergyCalorie cal = 4.184 J Pressure Atmosphere 1 atm = 1.064 x 10 2 kPa = 760 mm Hg

42. برگزیده پیشوندهای مورد استفاده درSI مثالمفهومنماد اختصاریپیشوند 1 Mm = 1x10 6 m10 6 Mمگا 1 kg = 1x10 3 g10 3 kکیلو 10daدکا 1 dm = 1x10 -1 m10 -1 dدسی.......10 -2 cسانتی 1 mm = 10 -3 m10 -3 mمیلی.......10 -6 µ میکرو 1 ng = 10 -9 g10 -9 nنانو.......10 -12 pپیکو.......10 -15 fفمتو

43. Properties of Matter Extensive Properties ( خاصيت مقدارى ) : Properties that depend on the amount of matter present in a sample. MassVolumeHeat Capacity Intensive Properties ( خاصيت شدتى ): Properties that do NOT depend on the amount of matter present in a sample. ColorTemperatureDensity Melting PointSpecific HeatBoiling Point

44. Temperature and Thermal Energy Temperature: A measure of the “hotness”and “coldness” of an object; a measure of the average kinetic energy of the atoms and molecules of the object. The higher the temperature, the more kinetic energy the atoms and/or molecules have. Thermal Energy: Often called “heat”, it is the form of energy toward which all other forms tend to go.

45. (Temperature) دما

46. اندازه گیری دما

47. تبدیل واحدهای دما کلوین به سانتی گراد: فارنهایت به سانتی گراد: Note: K and not °K

48. Sample calculations involving temperatures Example: Convert 73.6 o F to Celsius and Kelvin temperatures. o C = (5/9)(73.6 o F - 32) = (5/9)(41.6) o C = (5/9)( o F - 32) K = o C + 273.15 = 23.1 o C K = 23.1 o C + 273.15 = 296.3 K

49. حجم

50. ابزارهای اندازه گیری حجم

51. Dimensional Analysis How many meters are in each of the following? 21 km1023570  m (21 km)(1 x 10 3 m) = 21 x 10 3 m = km (1023570  m)( 1 m ) = (10 6  m) 1.023570 m 2.1 x 10 4 m

52. Sample Calculations Involving Volumes How many mL are in 3.456 L? (3.456 L)(1000 mL) L = 3456 mL How many L are in 23.7 cm3? (23.7 cm 3 )( cm 3 )( 1 mL )( )( 1 L_ _)(10 6 _)(10 6  L) (1 cm 3 ) cm 3 ) (1000 mL) ( 1L ) = 2.37 x 10 4  L = 23 700 L

53. Dimensional Analysis How many mL are in 3.0 ft 3 ? 1 ft = 12 in 1 in = 2.54 cm1 cm 3 = 1 mL (3.0 ft 3 )(12 in)(12 in)(12 in)(2.54 cm)(2.54 cm)(2.54 cm)(1 mL) (1 ft) (1 ft) (1 ft) (1 in) (1 in) (1 in) (1 cm 3 ) = 8.5 x 10 4 = 8.5 x 10 4 mL How many ns are in 23.8 s? (23.8 s)(10 9 ns) (1 s) = 23.8 x 10 9 ns = 2.38 x 10 10 ns

54. Mass and Weight Mass: the measure of the quantity or amount of matter in an object. The mass of an object does not change as its position changes. Weight: A measure of the gravitational attraction of the earth for an object. The weight of an object changes with its distance from the center of the earth. Mass is measured using a BALANCE. Weight is measured using SCALES.

55. Sample Calculations Involving Masses How many  g are in 2.56 kg? How many  g are in 2.56 kg? (2.56 kg)(10 3 g)(10 6  g) (1 kg) ( 1 g) (1 kg) ( 1 g) = 2.56 x 10 9  g How many g are in 2.578 x 10 12 ng? How many g are in 2.578 x 10 12 ng? (2.578 x 10 12 ng) (1 g) (10 9 ng) (10 9 ng) = 2578 g

56. )Density( دانسیته d = m/V unit: commonly g/mL m = Vd  V = m/d Mass and volume are extensive properties Density is an intensive property

57. Density What is the density of a cubic block of wood that is 2.4 cm on each side and has a mass of 9.57 g? volume = [2.4 cm x 2.4 cm x 2.4 cm]= 13.8 cm 3 density = (9.57 g)/(13.8 cm 3 ) = 0.69 g/cm 3 = 0.69 g/mL Note again: 1 cm 3 = 1 mL

58. Density What is the mass of a cube of osmium that is 1.25 inches on each side? Density is 22.48g/cm3

59. Wrong units

60. (Uncertainties) عدم قطعیت Systematic errors –Thermometer constantly 2°C too low. Random errors –Limitation in reading a scale. Precision –Reproducibility of a measurement. Accuracy –How close to the real value.

61. صحت و دقت در اندازه گیری صحت به معنای درستی و به دست آوردن مقدار واقعی در یک اندازه گیری دقت به معنای نزدیک بودن مقدارها در چند بار اندازه گیری صحت خوب دقت خوب صحت بد دقت خوب صحت بد دقت بد

62. Chapter 1, Questions 3, 5, 12, 14, 17, 30, 38, 43, 49, 59, 60