This preview shows pages 1–3. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: 1442 Final Review website: http://dipowell1.home.mindspring.com The final review will be different from previous reviews. You need to work the problems and come with questions. There will be no lecture, just questions answered. If you need to know the date and time, go to the link for review dates. Chapter 13 Properties of Solutions Useful Information: R = 0.08206 L . atm/mol . K = 8.314 J/mol . K 1 atm = 760 torr = 760 mm Hg P soln = (P solv ) (X solv ) = MRT ( R = 0.0821 Latm/mol K) π ∆ T f = imK f ( or ∆ T b ) ∆ P soln = (P solv ) ( X solute ) P total = P A X a + P b X b (two volatile liquids) 1. An aqueous solution of sulfuric acid (H 2 SO 4 ) has a concentration of 11.0 M and a density of 1.59 g/mL. What is the mass percent of H 2 SO 4 in this solution? (The molar mass of H 2 SO 4 is 98.1 g/mol; the molar mass of H 2 O is 18.02 g/mol.) a) 37.5% b) 84.3% *c) 67.9% d) 59.0% e) 11.0% 2. Rank the substances listed below in order of increasing solubility in water: I. CH 3 CH 2 CH 2 CH 3 II. CH 3 OH III. CH 3 CH 2 CH 2 CH 2 OH a) I < II < III *b) I < III < II c) II < I < III d) II < III < I e) III < II < I 3. What is the vapor pressure of a solution formed by dissolving 0.500 mol of a nonvolatile nonelectrolyte in 2.50 mol of methanol at 20°C? (The vapor pressure of pure methanol is 88.7 torr at 20°C.) a) 14.8 torr b) 17.7 torr *c) 73.9 torr d) 63.4 torr e) 106 torr 4. At a given temperature, you have a mixture of benzene (vapor pressure of pure benzene = 745 torr) and toluene (vapor pressure of pure toluene = 290. torr). The mole fraction of benzene in the solution is 0.425. Assuming ideal behavior, calculate the mole fraction of toluene in the vapor above the solution. a) 0.425 b) 0.517 c) 0.566 d) 0.638 *e) 0.345 5. When acetone is mixed with water, the ∆H soln is found to be exothermic. How does the actual vapor pressure of the solution compare to that predicted by Raoult’s law? a) The actual vapor pressure of the solution is greater than that predicted by Raoult’s law. *b) The actual vapor pressure of the solution is less than that predicted by Raoult’s law. c) The actual vapor pressure is the same as that predicted by Raoult’s law. 6. Which of the aqueous solutions below has the lowest freezing point? a) 0.12 m Na 3 PO 4 b) 0.25 m KCl *c) 0.22 m CaCl 2 d) 0.30 m NaCl e) 0.40 m glucose (a nonelectrolyte) 7. Pure cyclohexane (C 6 H 12 ) boils at 81.0°C. What is the boiling point of a solution in which 40.0 g of bromine (Br 2 , a nonelectrolyte) is dissolved in 500 g of cyclohexane? (K b for cyclohexane = 2.80 °C/m) a) 79.6° C b) 83.8° C c) 81.7° C d) 78.2° C *e) 82.4° C 8. A 100.0 mL aqueous solution containing 1.73 g of an unknown nonvolatile nonelectrolyte generates an osmotic pressure of 2.72 atm at 25.0°C. What is the molar mass of the unknown compound?...
View Full Document
This note was uploaded on 10/13/2009 for the course CHEM 1442 taught by Professor Rogers during the Fall '08 term at UT Arlington.
- Fall '08