2. Match each liquid to its surface tension (in millinewtons per meter, mn*m -1, at 20 C).

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1 1. Using your knowledge of the types of intermolecular forces present in CO 2, CH 3 CN, Ne, and CH 4 gases, assign each gas to its van der Waals a parameter. a ( ) gas 2. Match each liquid to its surface tension (in millinewtons per meter, mn*m -1, at 20 C) The vapor pressure of dimethyl ether at -58 C is 18.1 kpa and its enthalpy of vaporization is kj/mol. What s the normal boiling point of dimethyl ether?

2 4. Given the pressure-temperature phase diagram for CO 2 below, answer the following questions. a. Label these phases on the diagram: solid, liquid, gas, supercritical fluid b. Label these points: triple point, critical point c. Label any two points where CO 2 is in dynamic equilibrium. d. Which CO 2 phase is denser, solid or liquid? e. What s the normal sublimation point of CO 2? f. What s the vapor pressure of CO 2 at -20 C? g. What phase is CO 2 in at -80 C and 700 atm? 5. Using the ideal gas equation and then the van der Waals equation, calculate the pressure at 298 K exerted by 1.00 mol H 2 (g) when confined in a volume of a) 30.0 L; b) 1.00 L; c) 50.0 ml. How does the reliability of the ideal gas law depend on pressure?

3 6. Using the like-dissolves-like rule, explain why soap is effective at removing nonpolar grease stains from clothing while washing with polar water? 7. The volume of blood in the body of a certain deep-sea diver is about 6.00L. Blood cells make up about 55% of the volume, and the remaining 45% is the aqueous solution called plasma. What is the maximum volume of nitrogen measured at 1.00atm and 37 C that could dissolve in the diver s blood plasma at a depth of 93m, where the pressure is 10.0atm? Assume that the Henry s constant for nitrogen at 37 C (body temperature) is 5.8x10-4 mol/l*atm. 8. a) Fill in the blanks in the figure below with the correct enthalpy change: H L (lattice enthalpy), H hyd (enthalpy of hydration), and H sol (enthalpy of solution). b) Is this an exothermic or endothermic process? Gas of ions Enthalpy Solid Solution

4 9. a) The molar solubility of silver bromide, AgBr, at 25 C is 0.88µmol/L. What is the value of K sp fro silver bromide? b) The solubility product of lead(ii) fluoride, PbF 2, is 3.7x10^-8. Estimate the molar solubility of the salt. c) Calculate the solubility of mercury(i) chloride (Hg 2 Cl 2, K sp =2.6x10^-18) in 0.150M NaCl(aq) and compare that to the solubility of mercury(i) chloride in pure water. 10. Chloride ion is added to a solution containing the following concentration of soluble salts: 0.020mol/L Pb(NO 3 ) 2 (aq) and mol/L AgNO 3 (aq). a. Determine the order in which each ion precipitates as the concentration of chloride ions is increased and give the concentration of Cl - when precipitation begins. b. Calculate the concentration of the first ion to precipitate that remains in solution when the second ion precipitates.

5 11. The following graph represents the effect of molal concentration of a non-volatile solute (with i=1.84) on the boiling point elevation of an unknown solvent. Using the graph, determine the identity of the solvent. ΔTb vs solute molality for Unknown solvent ΔTb (oc) molality (mols / kg) 12. Compare the k f (-1.86 K*kg/mol) and k b (0.512 K*kg/mol) for water. Using these numbers, estimate why freezing point depression is more commonly used to determine the MW of solutes than boiling point elevation.

6 13. Suppose that 10.0 g of an organic compound used as a component of mothballs is dissolved in 80.0 g of benzene. The freezing point of the solution is 1.20 o C. a. What is an approximate molar mass of the organic compound? b. Elemental analysis of the substance indicated that the empirical formula is C 3 H 2 Cl. What is its molecular formula? c. What is the molar mass? 14. A M solution of C 6 H 12 O 6 (aq) is separated from a M CO(NH 2 ) 2(aq) solution by a semipermeable membrane at 25 o C. For both compounds i=1. a. Which solution has the higher osmotic pressure? b. Which solution becomes more dilute with the passage of H 2 O molecules through the membrane? c. To which solution should an external pressure be applied to maintain an equilibrium flow of H 2 O molecules across the membrane? d. What external pressure (in atm) should be applied in part (c)? 15. Which of the following concentrations of NaCl would raise the boiling point of water the most? The van t-hoff factor does change with concentration, but for this problem we will assume it is constant. 5% by mass 0.1 m 0.1 M χ NaCl = List the following aqueous solutions in order of decreasing freezing point. Assume complete dissociation of all ionic compounds. 0.1 m sugar 0.08 m CaCl m MgCl m KBr

Chapter 11. General Chemistry. Chapter 11/1

Chapter 11. General Chemistry. Chapter 11/1 Chapter 11 Solutions and Their Properties Professor Sam Sawan General Chemistry 84.122 Chapter 11/1 Solutions Solution: A homogeneous mixture. Solvent: The major component. Solute: A minor component. Copyright