Chemistry Handout :-bd

1. Chemistry: The Study of Change

3. Sanitation systems

4. Surgery with anesthesia

5. Vaccines and antibiotics

6. Energy and the Environment

7. Fossil fuels

8. Solar energy

9. Nuclear energy1.1

11. Polymers, ceramics, liquid crystals

12. Room-temperature superconductors?

13. Molecular computing?

14. Food and Agriculture

15. Genetically modified crops

16. “Natural” pesticides

17. Specialized fertilizers1.1

18. testedmodified The scientific method is a systematic approach to research A hypothesis is a tentative explanation for a set of observations A law is a concise statement of a relationship between phenomena that is always the same under the same conditions. 1.3

19. Chemistry is the study of matter and the changes it undergoes Matter is anything that occupies space and has mass. A substance is a form of matter that has a definite composition and distinct properties. water, ammonia, sucrose, gold, oxygen 1.4

20. soft drink, milk, solder cement, iron filings in sand A mixture is a combination of two or more substances in which the substances retain their distinct identities. Homogenous mixture – composition of the mixture is the same throughout. Heterogeneous mixture – composition is not uniform throughout. 1.4

21. magnet distillation Physical means can be used to separate a mixture into its pure components. 1.4

22. Fractional Distillation Apparatus 12.6

25. Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper 22.2

27. Water (H2O) Glucose (C6H12O6) Ammonia (NH3) A compound is a substance composed of atoms of two or more elements chemically united in fixed proportions. Compounds can only be separated into their pure components (elements) by chemical means. 1.4

28. 1.4

29. gas solid liquid Three States of Matter 1.5

30. sugar dissolving in water ice melting hydrogen burns in air to form water Physical or Chemical? A physical change does not alter the composition or identity of a substance. A chemical change alters the composition or identity of the substance(s) involved. 1.6

32. length

34. temperature

35. color1.6

36. weight = c x mass A 1 kg bar will weigh on earth, c = 1.0 1 kg on earth on moon, c ~ 0.1 0.1 kg on moon Matter - anything that occupies space and has mass. mass – measure of the quantity of matter SI unit of mass is the kilogram (kg) 1 kg = 1000 g = 1 x 103 g weight – force that gravity exerts on an object 1.7

37. Volume – SI derived unit for volume is cubic meter (m3) 1 cm3 = (1 x 10-2 m)3 = 1 x 10-6 m3 1 dm3 = (1 x 10-1 m)3 = 1 x 10-3 m3 1 L = 1000 mL = 1000 cm3 = 1 dm3 1 mL = 1 cm3 1.7

38. mass density = volume A piece of platinum metal with a density of 21.5 g/cm3 has a volume of 4.49 cm3. What is its mass? m m d = d = V V Density – SI derived unit for density is kg/m3 1 g/cm3 = 1 g/mL = 1000 kg/m3 = 21.5 g/cm3 x 4.49 cm3 = 96.5 g m = d x V 1.7

40. Dissolved in water (H+ Cl-), hydrochloric acidAn oxoacid is an acid that contains hydrogen, oxygen, and another element. HNO3 2.7

41. 2HCl (aq) + Mg (s) MgCl2 (aq) + H2 (g) 2HCl (aq) + CaCO3 (s) CaCl2 (aq) + CO2 (g) + H2O (l) Acids Have a sour taste. Vinegar owes its taste to acetic acid. Citrus fruits contain citric acid. Cause color changes in plant dyes. React with certain metals to produce hydrogen gas. React with carbonates and bicarbonates to produce carbon dioxide gas Aqueous acid solutions conduct electricity. 4.3

42. pH – A Measure of Acidity Solution Is pH = 7 neutral acidic pH < 7 basic pH > 7 15.3

43. 2.7

44. sodium hydroxide NaOH potassium hydroxide KOH Ba(OH)2 barium hydroxide A base can be defined as a substance that yields hydroxide ions (OH-) when dissolved in water. 2.7

45. Bases Have a bitter taste. Feel slippery. Many soaps contain bases. Cause color changes in plant dyes. Aqueous base solutions conduct electricity. 4.3

46. Salts A salt, is defined as the product formed from the neutralization reaction of acids and bases. Salts are ionic compounds composed of cations (positively charged ions) and anions (negative ions) so that the product is electrically neutral (without a net charge)

47. acid + base salt + water HCl (aq) + NaOH (aq) NaCl (aq) + H2O H+ + Cl- + Na+ + OH- Na+ + Cl- + H2O H+ + OH- H2O Neutralization Reaction 4.3

48. 2.7

49. Solution Solvent Solute A solution is a homogenous mixture of 2 or more substances The solute is(are) the substance(s) present in the smaller amount(s) The solvent is the substance present in the larger amount H2O Soft drink (l) Sugar, CO2 Air (g) N2 O2, Ar, CH4 Pb Sn Soft Solder (s) 4.1

51. Colloids are the same as suspensions, except they don’t leave sediments

52. In general, a colloid or colloidal dispersion is a substance with components of one or two phases.

54. Classification of Colloids

57. Dalton’s Atomic Theory (1808) Elements are composed of extremely small particles called atoms. All atoms of a given element are identical, having the same size, mass and chemical properties. The atoms of one element are different from the atoms of all other elements. Compounds are composed of atoms of more than one element. The relative number of atoms of each element in a given compound is always the same. Chemical reactions only involve the rearrangement of atoms. Atoms are not created or destroyed in chemical reactions. 2.1

58. 2 Law of Multiple Proportions 2.1

59. 16 X 8 Y + 8 X2Y Law of Conservation of Mass 2.1

60. A X Mass Number Element Symbol Z Atomic Number 1 2 3 H (D) H (T) H 1 1 1 235 238 U U 92 92 Atomic number (Z) = number of protons in nucleus Mass number (A) = number of protons + number of neutrons = atomic number (Z) + number of neutrons Isotopes are atoms of the same element (X) with different numbers of neutrons in their nuclei 2.3

61. 2.3

62. 14 11 C C 6 6 How many protons, neutrons, and electrons are in How many protons, neutrons, and electrons are in ? ? Do You Understand Isotopes? 6 protons, 8 (14 - 6) neutrons, 6 electrons 6 protons, 5 (11 - 6) neutrons, 6 electrons 2.3

63. Isomers - are compounds with the same molecular formula but different structural formula. Isomers do not necessarily share similar properties unless they also have the same functional groups.

64. Isobars Isobars are defined as the atoms or ions having same atomic mass but different atomic numbers. They are generally formed by subsequent beta emissions in which the atomic number changes by one unit but the atomic mass remains almost same as the mass of beta particles are negligible as compared to neutrons or protons. Example: 54Cr and 54Fe, 112Cd and 112Sn are isobars.

65. Allotropes Different forms of the same element in the same physical state Examples: O3 and O2 ; Diamond and Graphite

67. Noble Gas Halogen Alkali Earth Metal Period Group Alkali Metal 2.4

68. Chemistry In Action Natural abundance of elements in Earth’s crust Natural abundance of elements in human body 2.4

69. H2 H2O NH3 CH4 A molecule is an aggregate of two or more atoms in a definite arrangement held together by chemical bonds A diatomic molecule contains only two atoms H2, N2, O2, Br2, HCl, CO A polyatomic molecule contains more than two atoms O3, H2O, NH3, CH4 2.5

70. 11 protons 11 electrons 11 protons 10 electrons Na+ Na 17 protons 18 electrons 17 protons 17 electrons Cl- Cl An ion is an atom, or group of atoms, that has a net positive or negative charge. cation – ion with a positive charge If a neutral atom loses one or more electrons it becomes a cation. anion – ion with a negative charge If a neutral atom gains one or more electrons it becomes an anion. 2.5

71. A monatomic ion contains only one atom Na+, Cl-, Ca2+, O2-, Al3+, N3- A polyatomic ion contains more than one atom OH-, CN-, NH4+, NO3- 2.5

72. How many protons and electrons are in ? How many protons and electrons are in ? 27 78 3+ 2- Al Al 13 34 Do You Understand Ions? 13 protons, 10 (13 – 3) electrons 34 protons, 36 (34 + 2) electrons 2.5

73. 2.5

74. 2.6

75. molecular empirical H2O A molecular formula shows the exact number of atoms of each element in the smallest unit of a substance An empirical formula shows the simplest whole-number ratio of the atoms in a substance H2O CH2O C6H12O6 O3 O N2H4 NH2 2.6

77. the sum of the charges on the cation(s) and anion(s) in each formula unit must equal zeroThe ionic compound NaCl 2.6

78. 2 x +3 = +6 3 x -2 = -6 1 x +2 = +2 2 x -1 = -2 1 x +2 = +2 1 x -2 = -2 Formula of Ionic Compounds Al2O3 Al3+ O2- CaBr2 Ca2+ Br- Na2CO3 Na+ CO32- 2.6

79. 2.6

80. 2.7

83. TOXIC! Laughing Gas Molecular Compounds HI hydrogen iodide NF3 nitrogen trifluoride SO2 sulfur dioxide N2Cl4 dinitrogen tetrachloride NO2 nitrogen dioxide N2O dinitrogen monoxide 2.7

84. 2.7