3a. Oxalic acid should be the most readily soluble in water because it is polar and can form hydrogen bonds. by simple mixing.

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1 Chapter 13 Answers Practice Examples 1a. 16.% ethanol by mass 1b. (a) 0.97 ; (b) 3.73 M ; (c).3 m. a b. (a) M ; (b) 0.36m ; (c) a. Oxalic acid should be the most readily soluble in water because it is polar and can form hydrogen bonds. 3b. I should dissolve well in CCl by simple mixing. a. Suggestion 1: 31 g NHCl crystallized ; Suggestion : 6 g of NH Cl crystallized. b. KNO 7% KClO 38% K SO 1% 3 5a atm O pressure 5b atm 6a. P hex = 11 mmhg ; P pen = 17 mmhg ; P tot = 39 mmhg. 6b. P tol = 13.0 mmhg ; P benz = 51.5 mmhg ; P tot = 6.5 mmhg. 7a. yhexane = 0.69, y pentane = b. y = 0.0, y = t 8a atm b 8b g 9a b atm 10a. (a) 0.1 m ; (b) 377 g/mol ; (c) C17H0O6N. 10b. Lower than mmhg. 11a atm 11b ml conc soln Copyright 011 Pearson Canada Inc. 1

2 Integrative Example A. 9.3% HO, χ phenol = B. (a) 0.8 mmhg; (b) 0. mmhg. Exercises 1. NH OH s bg should be the most soluble. 3. Salicyl alcohol probably is moderately soluble in both benzene and water. The reason for this assertion is that salicyl alcohol contains a benzene ring, which would make it soluble in benzene, and also can use its OH groups to hydrogen bond to water molecules. 5. (c) Formic acid and (f) propylene glycol are soluble in water. (b) Benzoic acid and (d) 1- Butanol are only slightly soluble in water. (a) Iodoform and (e) chlorobenzene are insoluble in water. 7. KF is probably the most water soluble, based on smallest lattice energy g NaBr/100 g solution L sol'n 13. For water, the mass in grams and the volume in ml are about equal; the density of water is close to 1.0 g/ml. For ethanol, on the other hand, the density is about 0.8 g/ml. As long as the final solution volume after mixing is close to the sum of the volumes for the two pure liquids, the percent by volume of ethanol will have to be larger than its percent by mass. This would not necessarily be true of other ethanol solutions. It would only be true in those cases where the density of the other component is greater than the density of ethanol g HCH3O M M ml conc. soln M m g I M, 5.6 m. 31a. =.187, = 0.7, CH 7 16 CH 8 18 CH = Copyright 011 Pearson Canada Inc.

3 31b mol% C7H 16,.7 mol% C8H 18, 38.6 mol% C9H 0. 33a b ml glycerol atoms, Pb m 1a. Unsaturated 1b. 3.0 g KClO M 10 g CH (natural gas) M 9. Because of the low density of molecules in the gaseous state, the solution volume remains essentially constant as a gas dissolves in a liquid. Changes in concentrations in the solution result from changes in the number of dissolved gas molecules. This number is directly proportional to the mass of dissolved gas. 51. Pb = 0.6 mmhg, P t = 16.3 mmhg, P tot = 56.9 mmhg 53. P sol'n = 3. mmhg 55. ye =0.68, y s = mmhg Both the flowers and the cucumber contain ionic solutions (plant sap), but both of these solutions are less concentrated than the salt solution. Thus, the solution in the plant material moves across the semipermeable membrane in an attempt to dilute the salt solution, leaving behind wilted flowers and shriveled pickles (wilted/shriveled plants have less water in their tissues) L solvent atm Copyright 011 Pearson Canada Inc. 3

4 a. 0. C / m 71b. Cyclohexane is the better solvent for freezing-point depression determinations of molar mass, because a less concentrated solution will still give a substantial freezing-point depression. 73. CHNO CHS g NaCl, No a C 81b C 81c C 81d C 81e C 81f C 81g. < C 83. The combination of NH 3 (aq) with HCH3O(aq), results in the formation of NH CH3O(aq), which is a solution of the ions NH + and CH 3 COO -. This solution of ions or strong electrolytes conducts a current very well. 85. The answer is (d). Integrative and Advanced Exercises g HO 9..5 kg HO % palmitic acid 97. urea sucrose , mole fraction of water = a m 3 100b m 105. Volume % N 65.38%, volume % O 3.6%. Copyright 011 Pearson Canada Inc.

5 g CuSO 5H O g / L, 0.73 atm L Feature Problems 11a. HCl b. The composition of HCl(aq) changes as the solution boils in an open container because the vapor has a different composition than does the liquid. Thus, the component with the lower boiling point is depleted as the solution boils. The boiling point of the remaining solution must change as the vapor escapes due to changing composition. 11c. The azeotrope occurs at the maximum of the curve: at HCl =0.1 and a boiling temperature of 110 C. 11d. HCl = a. 90.0% 115b. CaCl 6 HO deliquesces if the relative humidity is over 3%. Thus, CaCl 6 HO will deliquesce. 115c. If the substance in the bottom of the desiccator has high water solubility, its saturated solution will have a low water, which in turn will produce a low relative humidity. 116a. Using 0.9% NaCl (aq) and i =.0 gives Tf = 0.60 C, fair agreement with 0.5 C. 116b. Tf = 0.60 C, close to the defined freezing point of 0.5 C. Self-Assessment Exercises 10. The answer is (b). 11. The answer is (d). 1. The answer is (a). 13. The answer is (d). 1. The answer is (c). 15. Unsaturated 16a M Na 16b. 0.3 M Copyright 011 Pearson Canada Inc. 5

6 16c. 8.1atm 16d. o 0.60 C 17a M C3H8O 3 17b.. M HO 17c. 3.0 m HO 17d e. 75.8% b, -d, 3-d, -a The answer is (b) The magnitude of ΔH lattice is larger than the sum of the ΔH hydration of the individual ions. 13. The answer is (a) The answer is (b). 13. The answer is (a) The answer is (e) The answer is (c). Copyright 011 Pearson Canada Inc. 6

Physical Properties of Solutions

Physical Properties of Solutions Chapter 12 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 12.1- Types of solutions A solution is a homogenous mixture of 2 or