Physical Properties of Solution

Chapter 13: physical properties of Solution. Which of the following liquids would be the best solvent for iodine, I2 ? a) CHCl3 b) H2O c) CCl4 d) CH3OH e) CH2Cl2 ************************************************************** Which of the following liquid pairs are least miscible? a) C6H6, C6H14 b) H2O, CH3CH2CH2OH c) H2O, CH3COOH (acetic acid) d) H2O, CH3CH2OH e) C6H14, H2O ************************************************************** Calculate the molality (m) of a 0.800 M solution of a salt (molar mass =51.9 g/mol) dissolved in ethanol if the solution density is 0.821g/mL. a) 0.760 b) 0.892 c) 1.03 d) 1.16 e) 0.652 ************************************************************** Calculate the decrease in the vapor pressure (in mmHg) of water caused by the addition of 551 g sucrose (a non-dissociating and non-volatile solute with molar mass =342.0g/mol) to 1000-0 WO at 25 °C Vapor pressure of water at 25 °C is 23.8 mmHg. (Molar mass of H2O =18.0 g/mol) a) 0.671 b) 0.896 c) 0.788 d) 0.552 e) 0.432 ************************************************************** Which of the following aqueous solutions has the lowest freezing? a) 0.12 m Ca(NO3)2 b) pure water d) 0.16 m KCl e) 0.15 m Na2SO4 c) 0.20 m C12H22O11 (sucrose) A solution of 0.246 g of an unknown non-dissociating solute in 22.0 g of C10H16O freezes at 17.7 °C. Calculate the molar mass of the solute (in g/mol). Given Kf for C10H16O =40.0 °C/m and its freezing point = 20.5 °C. ) a) 1.4 x102 b) 11.6 x 102 c) 1.2 x 102 d) 1.0 x 102 e) 1.8 x 102 ************************************************************** Which liquids in each of the following pairs are least miscible? a) H2O , CH3(CH2)5CH3 c) H2O , CH3COOH (acetic acid) e) H2O , CH3CH2CH2OH b) CH3(CH2)4CH3 , C6H6 d) H2O , CH3CH2OH ************************************************************** A solution containing 150.0 g H2O (molar mass = 18.0 g.mol) and 100.0 g glycerol, C3H8O3 (molar mass = 92.0 g/mol) has a density of 1.10 g/mL. Calculate the molar concentration of glycerol in solution. a) 5.98 b) 2.74 c) 3.99 d) 3.42 e) 4.78 ************************************************************** Calculate the decrease in the vapor pressure( in mmHg) of water caused by the addition of 450.0 g sucrose (a non-dissociating solute), (molar mass =342.0 g/mol) to 1000.0 g H2O at 25 °C. Vapor pressure of water at 25 °C is 23.8 mmHg. a) 0.503 b) 0.430 c) 0.382 d) 0.551 e) 0.623 ************************************************************** Which of the following aqueous solutions is expected to have the lowest boiling point? a) 0.40M AlCl3 c) 0.40M HCl e) 0.40M Na2SO4 b) 0.40M C12H22O11 (sucrose) d) 0.40M HC2H3O2 (weak acid) ************************************************************** A solution of 0.246 g of an unknown solute in 22.0 g of C10H16O freezes at 176.8 °C. Calculate the molar mass of Solute (in g/mol). Given: Kf for C10H16O = 40.0 °C/m and its freezing point = 179.8 °C. a) 1.1 x102 b) 1.3 x102 c) 1.5 x102 d) 1.7 x102 e) 1.9 x102 ************************************************************** A sample 2.56 g of polystyrene (a non-dissociating solute,) was dissolved in enough benzene to form 100.0 mL solution. If the osmotic pressure of the solution was 9.08 mm Hg at 25 °C, calculate the molar Titus of the solute (in g/mol) is: a) 6.68 x104 b) 5.24 x104 c) 3.81 x104 d) 4.22 x104 e) 2.78 x104 ************************************************************** Which of the following factors contributes to a high viscosity for a liquid? a) High temperature b) Low boiling point c) Hydrogen bonding d) High vapor pressure e) London dispersion forces ************************************************************** The material that will cause the smallest depression in freezing point of a solution made by dissolving 0.1 mole of it in a certain amount of water is: a) Na2SO4 b) NaCl c) MgSO4 d) C6H12O6 e) CH3COOH ************************************************************** What is the molarity of 36.0% (by mass) acetic acid solution (d = 1.045 g/mL). Molar mass of acetic acid is 60.05 g/mol. a) 5.22 M b) 6.26 M c) 3.49 M d) 1.55 M e) 0.52 M The Henry's Law constant (k) for carbon monoxide in water at 25°C is 9.71 x 10-4 mol/(L.atm). How many grams of CO (molar mass 28 g/mol) will dissolve in 1.00 L of water if the partial pressure of CO is 2.75 atm? a) 2.20 x 10-1 g b) 1.40 x 10-2 g c) 7.48 x 10-2 g d) 5.20 x 10-2 g e) 1.43 x 10-1 g ************************************************************** Colligative properties depend on: a) the chemical properties of the solute. b) the chemical properties of the solvent. c) the masses of the individual ions. d) the molar mass of the solute. e) the number of particles dissolved. ************************************************************** 10. From the following list of aqueous solutions in water, select the one with the highest boiling point a) 1.0 m KNO3. b) 0.75 m NaCl. c) 0.75 m CuCl2. d) 2.0 m C12H22O11 (sucrose). e) 0.75 m K3PO4. ************************************************************** A 0.100 m K2SO4 solution has a freezing point of -0.43°C. What is the van't Hoff factor for this solution? (Kf = 1.86°C/m) a) 0.77 b) 2.8 c) 2.3 d) 3.0 e) 1.0 ************************************************************** The rule “Like Dissolves Like” means: ) a) Liquids can only dissolve other liquids and gases. b) Polar solvents dissolve non-polar solutes and non-polar solvents dissolve polar solutes. c) Gases can only dissolve gases. d) Polar solvents dissolve polar solutes and non-polar solvents dissolve non-polar solutes. e) Solvents can only dissolve solutes of similar molar mass. ************************************************************** The solubility of oxygen gas in water at 25°C and 1.0 atm pressure of oxygen is 0.041 g/L. Calculate the solubility of oxygen in water (in g/L) at 25°C and pressure of oxygen of 5.0 atm. a) 0.0410 b) 0.164 c) 0.205 d) 0.123 e) 3.00 ************************************************************** Calculate the molal concentration of KBr ( in mol/kg) in a solution prepared by dissolving 3.21 g of KBr in 897 g of water. Molar mass of KBr =119 g/mol. a) 0.0301 b) 0.0167 c) 0.0207 d) 0.0523 e) 0.0394 ************************************************************** The vapor pressure of pure water at 25°C is 23.8 torr. What is the vapor pressure (in torr) of water above a solution that is 30.0 % glucose by mass. ( glucose is a non-electrolyte, molar mass = 180.0 g/mol). a) 23.5 b) 22.8 c) 21.4 d) 1.02 e) 24.8 ************************************************************** The freezing point of ethanol (C2H5OH) is -114.6 °C. Calculate the freezing point of a solution (in °C) prepared by dissolving 60.0 g of glycerol (a non-electrolyte solute, molar mass = 92.0 g/mol) in 200.0 g of ethanol. Kf for ethanol = 2.00 °C/m. a) -122.2 b) 6.52 c) -120.0 d) -121.1 e) -114.6 ************************************************************** A solution is prepared by dissolving 2.60g of a strong electrolyte ( molar mass = 111 g/mol) in enough water to make 1.00 L of solution .The osmotic pressure of the solution is 1.67 atm at 25 °C. Calculate the van't Hoff factor,i , for the solute. a) 2.92 b) 1.10 c) 1.98 d) 0.84 e) 3.85 ************************************************************** A solution is prepared by dissolving 8.00 g of an unknown non-electrolyte in enough water to make 1.90 L of solution that has an osmotic pressure of 0.751 at at 25 °C. Calculate the molar mass of the solute (in g/mol). a) 3.83 x 10-3 b) 196 c) 228 d) 30.6 e) 261 **************************************************************