3. Solutions are homogeneous (1 phase) mixtures where 1 of the components (solvent) is found in larger quantities than the rest. All other components are said to be dissolved in the solvent. These components are called solutes.

4. Both solutes and solvents can be liquids, solids, or gases. Create a chart with solutes along the side and solvents at the top which shows examples of: gas in gas, gas in solid, gas in liquid, liquid in gas, etc.

5. GasLiquidSolid Gas in Liquid in Solid in SOLVENT SOLUTESOLUTE oxygen in air (nitrogen) oxygen in water air bubbles in ice water in air alcohol in water mercury in silver Sugar in water (syrup) Invisible dust in air tin in copper (bronze)

6. When solutes are dissolved in solvents the solutes formula is written followed by a bracketed subscript which follows. Examples: magnesium chloride is dissolved in water MgCl 2(aq) iodine is dissolved in alcohol I 2(al) Aqueous solutions have water as the solvent. They are always indicated by (aq) after the formula.

7. The ability to conduct electricity can be used to classify solutions. Electrolytes are substances which conduct electricity when dissolved in water. Ionic compounds are electrolytes and most molecular compounds are non-electrolytes. Solutions can also be categorized as acidic, basic or neutral. Litmus paper can be used in this determination. Questions - pg 269 # 1-8 Properties of Solutions

8. Why does solid NaCl dissolve easily in water? H and O atoms in water molecules do not share electron pairs equally. O H H

9. Why does solid NaCl dissolve easily in water? H and O atoms in water molecules do not share electron pairs equally. O H H -ve +ve H O H -ve Water molecules have oppositely charged ends. They are polar molecules

10. Why does solid NaCl dissolve easily in water? H O H H O H H O H H O H Moving water molecules collide with the ions of Na and Cl in solid NaCl crystals.

11. Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ Here is a small crystal of NaCl Drop the crystal in a container of water

12. Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ Here is a small crystal of NaCl Drop the crystal in a container of water

13. Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ H O H

14. Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ H O H

15. Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ H O H

16. Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ H O H

17. Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ H O H

18. Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ H O H

19. Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ H O H

20. Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ H O H

21. Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ H O H

22. Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ H O H

23. Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ H O H

24. Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+

25. Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ H O H

26. Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ H O H

27. Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ H O H

28. Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ H O H

29. Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ H O H

30. Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ H O H

31. Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- H O H

32. Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- H O H

33. Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- H O H

34. Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- H O H

35. Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- H O H

36. Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- H O H H O H

37. Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ H O H

38. Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ H O H

39. Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ H O H

40. Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ H O H

41. Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ H O H

42. Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ H O H

43. Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ H O H

44. Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ H O H If the positive end of a water molecule strikes a chloride ion with enough energy it pulls it away. The same thing happens if the negative oxygen end of a water molecule strikes a Na 1+ ion.

45. Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ H O H These types of interactions are called intermolecular and the NaCl crystal is dissociating. In reality each ion of Na and Cl become surrounding by a number of water molecules.

46. Cl 1- Na 1+ Cl 1- Na 1+ Cl 1- Na 1+ H O H H O H H O H H O H H O H H O H H O H H O H These complexes are called hydrated ions. All ions in water become hydrated.

47. Some substances do not easily dissolve in water.

48. When air is exhaled in water it does not easily dissolve. Why?

68. Air is made up mostly of nitrogen and oxygen. N 2 and O 2. Since they don't dissolve easily in water they must be non-polar. Both N 2 and O 2 molecules are non-polar so they are not strongly attracted by polar water molecules. N N Since all three pairs of electrons are equally shared this molecule is non-polar.

69. In general like dissolves like. Polar materials dissolve easily in polar solvents and non-polar materials dissolve easily in non- polar solvents. Water is often called the universal solvent because it dissolves so many different substances. This is due to the strong forces of attraction water molecules have on each other and on positive and negative particles in other substances.

70. O H H -ve +ve O H H -ve +ve The H end of one water molecule is strongly attracted to the O end of another water molecule. The special force of attraction is called a hydrogen bond and it occurs between molecules of substances with H and O, or H and N, or H and F.

71. Any molecular substance containing O atoms bonded to H atoms has polar regions which exert these attractive H bonds. For instance alcohols have OH groups. This allows them to easily mix with water. CH 3 OH H O H Attractive force +ve -ve

72. Any molecular substance containing O atoms bonded to H atoms has polar regions which exert these attractive H bonds. For instance alcohols have OH groups. This allows them to easily mix with water. CH 3 OH H O H H bond

73. Alcohol will dissolve in water but this solution does not conduct electricity. Why? There are no mobile ions present. CH 3 OH H O H H bond

74. Why does sugar dissolve in water and not conduct electricity. The OH groups form H bonds with water molecules. H O H H O H H O H H O H H O H C 6 H 12 O 6 No free ions are present.

75. Non-polar substances will dissolve in other non- polar substances. Non-polar molecules have no strongly positive or negative regions but they still have positive nuclei and negative electron clouds around them. ++

76. Non-polar substances will dissolve in other non- polar substances. Non-polar molecules have no strongly positive or negative regions but they still have positive nuclei and negative electron clouds around them. ++

77. Non-polar substances will dissolve in other non- polar substances. Non-polar molecules have no strongly positive or negative regions but they still have positive nuclei and negative electron clouds around them. ++

78. Non-polar substances will dissolve in other non- polar substances. Non-polar molecules have no strongly positive or negative regions but they still have positive nuclei and negative electron clouds around them. ++

79. Non-polar substances will dissolve in other non- polar substances. Non-polar molecules have no strongly positive or negative regions but they still have positive nuclei and negative electron clouds around them. ++

80. Non-polar substances will dissolve in other non- polar substances. Non-polar molecules have no strongly positive or negative regions but they still have positive nuclei and negative electron clouds around them. ++

81. Non-polar substances will dissolve in other non- polar substances. Non-polar molecules have no strongly positive or negative regions but they still have positive nuclei and negative electron clouds around them. ++ ++ If 2 non-polar molecules are side by side the electron clouds of one affect the electron clouds of the other

82. Non-polar substances will dissolve in other non- polar substances. Non-polar molecules have no strongly positive or negative regions but they still have positive nuclei and negative electron clouds around them. ++ ++ If 2 non-polar molecules are side by side the electron clouds of one affect the electron clouds of the other

83. Non-polar substances will dissolve in other non- polar substances. Non-polar molecules have no strongly positive or negative regions but they still have positive nuclei and negative electron clouds around them. ++++ If 2 non-polar molecules are side by side the electron clouds of one affect the electron clouds of the other + A region of slight positive charge is created Attractive force

84. ++++ + This slight attractive force brought about by the influence of one electron cloud of 1 molecule on the electron cloud of a molecule beside it is called London Dispersion Force (LDF). It explains why non-polar solvents dissolve non-polar solutes.

85. Questions - Pg. 277 # 3-5 Pg. 278 # 6,7 Pg. 279 # 8-10

86. Measuring Quantities of Solutes in Solutions The quantity of solute can be measured in grams or moles. The total volume of the solution is measured in L. The amount of solute in a given volume of solution is measured using these units: g L mol L or = kmol m3m3 = mol dm 3 ormolL -1 kmolm -3 moldm -3 M =

87. This leads to the development of the following equation: Concentration of a solution = # of moles of solute Volume, in L, of solution C = n V

88. Preparing Solutions From Solid Reagents Sample Problem Describe how to prepare 500 mL of a 0.035 M solution of sodium thiosulfate. Given: V = 500 mL =0.500 L C = 0.035 M Asked to Find:Mass of Na 2 S 2 O 3

89. Mass Mole Concentration Use n= m/MM Use C = n/V

90. Step 1 - Find n using C = n/V Rearrange this equation to get n = CV n = 0.035 M x 0.500 L = 0.0175 mol Step 2- Find m using n = m/MM Rearrange this equation to get m= n x MM = 0.0175 mol x 158.1 g/mol = 2.8 g

91. 1. get a 500 mL Volumetric Flask 2. Place it on a mass balance and tare the balance (zero it). 3. Mass out 2.8 g of Na 2 S 2 O 3 4. Fill the flask up, almost to the top and dissolve the solute. 5. Top up with distilled water to the calibration mark and stopper it.

92. Preparing Solutions From Solutions Determining Concentrations of Concentrated Reagents Concentrations of solutions, in molL -1, can be determined from density and percentage composition.

93. Sample Problem A solution of concentrated (conc.) HCl (hydrochloric acid) has a density of 1.25 g/mL and it is 35% HCl by mass. Find the concentration of the HCl.

94. density = 1.25 g/mL, 35% HCl Change density into units of mass and volume m = 1.25 g, V = 1 mL = 0.00100 L Mass Mole Concentration Given:

95. Step 1 - Find mass of HCl 35% of 1.25 g = 0.4375 g Step 2 - Find nHCl = m/mm = 0.4375 g/ 36.45 g/mol = 0.01199 mol Step 3 - Find C = n/V = 0.01199 mol/ 0.00100 L = 12 M

96. Describe how to prepare 1.5 L of 0.75 M HCl from this concentrated reagent. Solution: Find the volume of the concentrated reagent needed to prepare the solution. Given: Cd = 0.75 M, Vd = 1.5 L Cc = 12 M, Vc = ?

97. # of moles Concentrated Reagent = # of moles Diluted Reagent CcVc = CdVd Cc Vc = 0.75 M x 1.5 L 12 M = 0.094 L = 94 mL

98. 1. Get a 1.5 L Volumetric Flask 2. Measure 94 mL of concentrated HCl using gloves, apron, shield 3. Half fill the 1.5 L Volumetric flask with distilled water 4. Add the 94 mL of conc. HCl 5. Top up with distilled water to the calibration mark. AW not WA

99. Describe how to prepare 2.0 L of a 1.5 M solution of ammonium hydroxide from a concentrated reagent which is 14.5 M.

100. # of moles Concentrated Reagent = # of moles Diluted Reagent CcVc = CdVd Cc Vc = 1.5 M x 2.0 L 14.5 M = 0.207 L = 210 mL

101. 1. Get a 2.0 L Volumetric Flask 2. Measure 210 mL of concentrated NH 4 OH using gloves, apron, shield 3. Half fill the 2.0 L Volumetric flask with distilled water 4. Add the 210 mL of conc. NH 4 OH. Top up with distilled water to the calibration mark.

102. What is the concentration of a H 3 PO 4 concentrated reagent if its density is 1.4 g/mL and it is 45% phosphoric acid by mass. Describe how to prepare 250 mL of a 0.45 M solution of phosphoric acid from this concentrated reagent.

104. If 45 mL of a 0.15 molL -1 solution of lead(II) nitrate is combined with an excess of sodium iodide what mass of lead(II) iodide is formed. Assume a double displacement reaction.

105. Pb(NO 3 ) 2 (aq) + NaI (aq) PbI 2 (aq) + NaNO 3 (aq)

106. If 85 mL of a 1.6 molL -1 solution of hydrochloric acid is combined with an excess of magnesium what volume of hydrogen gas is formed at 24 o C and 101 kPa? Assume a single displacement reaction.

107. If 35 mL of 1.2 mol/L sulfuric acid is combined with 65 mL of a 0.95 mol/L solution of potassium hydroxide what mass of potassium sulfate is formed. The other product is water.

108. Prepare the following solutions 1.100 mL of a 1.0 M NaOH from solid 2. 500 mL of a 1.0 M HCl from 6.0 M solution 3. 500 mL of 0.223 M Na 2 S 2 O 3. 5H 2 O from a solid 4. 500 mL of 0.5 M NaOH from a solid 5. 1 L of a 1.0 M HCl from a 6.0 M solution 6. 1 L of 0.25 M Na 2 S 2 O 3. 5H 2 O from a solid 7. 1 L of 1.0 M NaOH from solid 8. 1 L of a 0.5 M HCl from a 6.0 M solution 9. 50 mL of a 0.5 M HCl from a 6.0 M solution 10. 1L of 2.0 M HCl for a 6.0 M solution

109. Prepare the following solutions 1.100 mL of a 1.0 M NaOH from solid 2. 500 mL of a 1.0 M HCl from 6.0 M solution 3. 500 mL of 0.223 M Na 2 S 2 O 3. 5H 2 O from a solid 4. 1L of 2.0 M HCl for a 6.0 M solution 5. 500 mL of 0.5 M NaOH from a solid 6. 1 L of a 1.0 M HCl from a 6.0 M solution 7. 1 L of 0.25 M Na 2 S 2 O 3. 5H 2 O from a solid 8. 50 mL of a 0.5 M HCl from a 6.0 M solution 9. 1 L of 1.0 M NaOH from solid 10. 1 L of a 0.5 M HCl from a 6.0 M solution