(3) The compound boron nitride (BN) has a high melting point (2967 ºC), high density, and is very hard. What is the best classification of this solid?

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1 Solids and Liquids Name: Period: (1) Identify the type of solid formed by each compound. (a) Ag (b) CO 2 (c) SiO 2 (d) wax (e) MgCl 2 (f) Fe (g) graphite (h) SO 2 (i) CaCO 3 (j) I 2 (k) rubber (l) SiC (2) Sketch a crystal structure for each of the following compounds. (a) Potassium chloride has a simple cubic structure. (b) Cesium bromide has a body centered cubic structure. (c) Barium chloride has a face centered cubic structure. (3) The compound boron nitride (BN) has a high melting point (2967 ºC), high density, and is very hard. What is the best classification of this solid? (4) The compound phosphorus pentachloride (PCl 5 ) has a low melting point (180 ºC), low density, and is soft. What is the best classification of this solid? (5) An unknown compound is a good conductor of heat and electricity and is both ductile and malleable. What is the best classification of this solid? (6) (a) Identify the intermolecular forces for the compounds ethane (C 2 H 6 ) and ethanoic acid (CH 3 COOH). (b) Which compound is expected to have a higher surface tension? Explain. (c) Which compound is expected to have the lower viscosity? Explain. Answers: (1) (a) metallic (b) molecular (c) network (d) amorphous (e) ionic (f) metallic (g) network (h) molecular (i) ionic (j)molecular (k) amorphous (l) network (2) (a) KCl (b) CsBr (c) BaCl 2 (3) network (4) molecular (5) metallic (6) (a) ethane has London dispersion forces; ethanoic acid has London dispersion forces, dipole interactions, and hydrogen bonding (b) ethanoic acid would have a higher surface tension than ethane because the intermolecular bonds are stronger since ethanoic acid can hydrogen bond (c) ethane would have a lower viscosity than ethanoic acid because the intermolecular bonds are weaker

2 Gases Name: Period: (1) Calculate the velocity for atoms in a sample of hydrogen gas at 30 ºC. (2) A monatomic gas has a velocity of 433 m/s at 300 K. Identify the gas (3) Draw a diagram to differential between diffusion and effusion. (4) Determine the relative rate of effusion for chlorine gas compared to krypton gas. (5) The rate of effusion of nitrogen gas is times the rate of effusion of an unknown gas. Identify the gas. (6) The rate of diffusion of a particular gas was found to be 24.0 ml/min. Under the same conditions, the rate of diffusion of methane (CH 4 ) is found to be 48.0 ml/min. What is the molar mass of the unknown gas? (7) (a) Identify the intermolecular forces for the gases methane (CH 4 ), propane (C 3 H 8 ), and methanoic acid (HCOOH). (b) Which compound, methane or methanoic acid, is expected to have a higher vapour pressure? Explain. (c) Which compound, methane or propane, is expected to have a higher vapour pressure? Explain. (8) Calcium carbonate decomposes to produce calcium oxide and carbon dioxide. A sample of calcium carbonate is heated and the carbon dioxide produced is collected over water at 25ºC. The volume of carbon dioxide collected is 100 ml The total pressure of the mixture is 641 torr and the vapour pressure of water at 25 ºC is 23.7 torr. (a) Write a balanced equation for the reaction. (b) Calculate the moles of carbon dioxide collected. (c) Determine the mass of calcium carbonate in the sample. (9) Ammonium nitrate decomposes into nitrous oxide (N 2 O) and water. What volume of N 2 O, collected over water at a total pressure of atm, can be produced by the decomposition of 2.6 g of ammonium nitrate at 22 ºC? The vapour pressure of water at this temperature is 21 torr. (10) Calculate the pressure if mol of nitrogen gas (a = 1.39 atm L 2 /mol 2 and b = L/mol) occupies a volume of 10.0 L at 25 ºC. (11) Calculate the pressure if 2.00 mol of water vapour (a = 5.46 atm L 2 /mol 2 and b = L/mol) occupies a volume of 18 L at 30 ºC using the ideal gas law and then the van der Waal s equation. Compare the results.

3 Answers (1) 1.94x10 3 m/s (2) 39.9 g/mol, argon (3) Before Diffusion Effusion After particles move from an area of higher concentration to an area of lower concentration particles escape through a hole in their container (4) (5) g/mol, xenon (6) 64.2 g/mol (7) (a) Both methane and propane have London dispersion forces, methanoic acid has London dispersion forces, dipole interactions, and hydrogen bonding (b) Methane will have a higher vapour pressure than methanoic acid. Methanoic acid has stronger intermolecular bonds (ie. hydrogen bonds) than methane. (c) Methane will have a higher vapour pressure than propane. Propane is larger (has a higher molecular mass) than methane and therefore has stronger intermolecular bonds. (8) (a) CaCO 3 CaO + CO 2 (b) 3.32x10-3 mol CO 2 (c) g CaCO 3 (9) L N 2 O (10) 1.22 atm (11) From ideal gas law, P = 2.76 atm and From van der Waal s, P = 2.71 atm. The ideal gas law gives a pressure that is higher than predicted by real behaviour

4 Phase Diagrams Name: Period: (1) Identify the phase(s) of matter for each statement. (a) Has the farthest spaced particles (b) Has the slowest particles (c) Compressible (d) Will take the shape of the container (e) Has the closest spaced particles (f) Has the fastest particles (2) Identify each phase change. (a) s l (c) l g (e) s g (b) l s (d) g l (f) g s (3) Consider the following phase diagram for water: (a) State the phase(s) of matter present at each of the given points. A. E. B. F. C. G. D. H. (b) Name the processes occurring at each of the given points. E. G. F. (c) Which is the more dense phase of water, solid or liquid? Explain. (d) What happens to the freezing point of water as the pressure in increased? What happens to the boiling point of water as the pressure in increased?

5 (4) Consider the following phase diagram for dioxide: (a) State the phase(s) of matter present at each of the given points. A. E. B. F. C. G. D. H. (b) Name the processes occurring at each of the given points. E. G. F. (c) What is the triple point of carbon dioxide? (d) What is the critical point of carbon dioxide? (e) Which is the more dense phase of carbon dioxide, solid or liquid? Explain. (f) What happens to the freezing point of carbon dioxide as the pressure in increased? What happens to the boiling point of carbon dioxide as the pressure in increased?

6 (5) Consider the phase diagram for carbon. (a) Name the processes occurring at each of the given points. A. B. C. (b) Name two allotropes of carbon. (c) Which of the two allotropes is higher in density? Explain. (d) What is the name given to point D. (6) Given the following information, sketch a phase diagram for oxygen. Oxygen has a normal freezing point of 55 K and a normal boiling point of 90 K. The critical point for oxygen is 155 K and 49.6 atm and the triple point is 54.4 K and 1.50x10-3 atm. The density of solid oxygen is greater than that of liquid oxygen. Indicate the phase present in each region of the diagram.

7 Answers: (1) (a) gas (b) solid (c) gas (d) gas + liquid (e) solid (f) gas (2) (a) melting (b) freezing (c) boiling (d) condensing (e) sublimation (f) deposition (3) (a) A. solid B. gas C. liquid D. supercritical fluid E. solid + gas F. solid + liquid G. liquid + gas H. solid, liquid, and gas (b) E. sublimation and deposition F. melting and freezing G. boiling and condensing (c) Liquid water is more dense than solid water. The boundary line between liquid and solid has a negative slope. At a given temperature, increasing pressure causes a phase change from solid to liquid. Since liquid is favoured over solid at high pressure, particles of the liquid must be more densely packed than particles of the solid. (d) freezing point decreases with increased pressure; boiling point increases with increased pressure (4) (a) A. solid B. gas C. liquid D. supercritical fluid E. solid + gas F. solid + liquid G. liquid + gas H. solid, liquid, and gas (b) E. sublimation and deposition F. melting and freezing G. boiling and condensing (c) triple point: ºC and 5.1 atm (d) critical point: 31 ºC and 72.8 atm (e) Solid carbon dioxide is more dense than liquid carbon dioxide. The boundary line between liquid and solid has a postive slope. At a given temperature, increasing pressure causes a phase change from liquid to solid. Since solid is favoured over liquid at high pressure, particles of the solid must be more densely packed than particles of the liquid. (f) freezing point increases with increased pressure; boiling point increases with increased pressure (5) (a) A. melting and solidifying B. melting and solidifying C. boiling and condensing (b) diamond and graphite (c) Diamond has a higher density than graphite since diamond is favoured at higher pressures (d) transition temperature (6)

8 Solutions Name: Period: (1) A solution is prepared by dissolving 50.0 g of sodium chloride in 150 ml of water. What is the molarity of the solution? (2) A solution is prepared by dissolving 25.0 g of sucrose (C 12 H 22 O 11 ) in 200 ml of water. What is the molality of the solution? What is the mass percent of the solution? (3) A solution is made by dissolving 50.0 g of cesium chloride in 50.0 g of water. The density of the solution is 1.58 g/ml. Calculate the mass percent, molarity, molality, and mole fraction of cesium chloride. (4) A 1.37 M solution of citric acid (H 3 C 6 H 5 O 7 ) in water has a density of 1.10 g/cm 3. Calculate the mass percent, molality, and mole fraction of citric acid for 1.00 L of solution. (5) Industrial nitric acid has a density of 1.42 g/ml and a mass percent of 70.0 %. Determine the molarity, molality, and mole fraction of nitric acid in this solution for 100 ml of solution. (6) Consider the following solubility graph for salts. (a) In general, what happened to the solubility of a salt as temperature increases? Which salts are exceptions to this trend? (b) What is the solubility (in g solute/100 g H 2 O) of potassium nitrate at 20 ºC? (c) What is the solubility (in g solute /100 g H 2 O) of potassium nitrate at 80 ºC? (d) What is the solubility (in mol solute /100 g H 2 O) of sodium nitrate at 60 ºC? (e) What is the solubility (in mol solute /100 g H 2 O) of sodium nitrate at 40 ºC? (f) What is the solubility (in g solute / kg H 2 O) of potassium bromide at 90 ºC? (7) Under which conditions will the solubility of carbon dioxide in water be the highest? Explain. Temperature Pressure 20 ºC 1.00 atm 20 ºC 1.50 atm 40 ºC 1.00 atm 40 ºC 1.50 atm

9 Answers: (1) 5.70 M (2) molal, 11.1 % (3) 50.0 %, 4.69 M, 5.94 molal, mole fraction CsCl = (4) 1.64 molal, 23.9 %, mole fraction citric acid = (5) 15.8 M, 37.0 molal, mole fraction nitric acid = (6) (a) In general, increasing the temperature increases solubility. Exceptions to this trend are Ce 2 (SO 4 ) 3 and Na 2 SO 4. (b) 30 g KNO 3 /100 g H 2 O at 20 ºC (c) 160 g KNO 3 /100 g H 2 O at 80 ºC (d) 1.41 mol NaNO 3 /100 g H 2 O at 60 ºC (e) 1.18 mol NaNO 3 /100 g H 2 O at 40 ºC (f) 900 g KBr/ 1.0 kg H 2 O at 20 ºC (7) A gas has the highest solubility at low temperatures and high pressures, therefore the solubility of carbon dioxide in water would be the highest at 20 ºC and 1.50 atm.

10 Solutions and Colligative Properties Name: Period: Solvent water (H 2 O) ethanol (CH 3 CH 2 OH) benzene (C 6 H 6 ) cyclohexane (C 6 H 12 ) Vapour Pressure at 25 ºC (mm Hg) Boiling Point (ºC) K b (ºC kg/mol) Freezing Point (ºC) K f (ºC kg/mol) (1) Calculate the vapour pressure of a solution made by dissolving 45 g of sodium chloride in 250 g of water at 25 ºC. (2) Calculate the vapour pressure of a solution made by dissolving 6.4 g of naphthalene (C 10 H 8 ) in 78.0 g of benzene at 25ºC. (3) Calculate the mass of anthracene (C 14 H 10 ) that was dissolved in 400 g of cyclohexane at 25 ºC to give a solution with a vapour pressure of mm Hg. (4) Calculate the vapour pressure of a solution made by dissolving 1.8 g of calcium chloride in 105 g of water at 25 ºC. (5) A solution is made by dissolving 15 g of ascorbic acid in 200 g of water at 25 ºC. The vapour pressure of the solution is found to be torr. Calculate the molar mass of ascorbic acid. (6) A solution is made by dissolving 500 mg of acetylsalicylic acid in 150 g of ethanol at 25 ºC. The vapour pressure of the solution is found to be torr. Calculate the molar mass of acetylsalicylic acid. (7) Which of the following pairs of compounds would form the most ideal solution: propanol (CH 3 CH 2 OH) and propane (C 3 H 8 ), pentane (C 5 H 12 ) and hexane (C 6 H 14 ), or methanol (CH 3 OH) and water? Explain. (8) Classify the following solutes as strong electrolytes, weak electrolytes, or non electrolytes. (a) HBr (e) LiOH (b) HOBr (f) sucrose (C 12 H 22 O 11 ) (c) ethanol, CH 3 CH 2 OH (g) KBr (d) propanoic acid, CH 3 CH 2 COOH (h) CH 3 NH 2 (9) Calculate the boiling point elevation of a solution prepared by dissolving 50.0 g of sucrose (C 12 H 22 O 11 ) in 350 g of water. (10) Calculate the freezing point depression of a solution prepared by dissolving 2.50 g of magnesium bromide in 80 g of water. (11) Calculate the boiling point and freezing point of a solution prepared by dissolving 16.0 g of potassium chloride in 175 g of water. (12) Calculate the boiling point and freezing point of a solution prepared by dissolving 8.50 g of phenol (C 6 H 5 OH) in 200 g of cyclohexane.

11 (13) A solution is prepared by dissolving 180 g of toluene in 400 g of benzene. The solution is found to have a freezing point of ºC. (a) What is the freezing point depression of the solution? (b) Given that toluene is a non electrolyte, what is the molar mass? (14) A solution is prepared by dissolving 50.0 g of an unknown compound in 100 g of water. The solution is does not conduct electricity and is found to have a boiling point of ºC. (a) What is the boiling point elevation of the solution? (b) What is the molar mass of the unknown compound? (15) Calculate the osmotic pressure of a solution containing 15.0 g of lithium chloride in 250 ml of water at 25 ºC. (16) Calculate the osmotic pressure of a solution containing 30 g of methanol (CH 3 OH) in 400 ml of water at 20 ºC. (17) A 20.0 mg sample of a protein is dissolved in water to make 25.0 ml of solution. The osmotic pressure of the solution is 0.56 torr at 25 ºC. Determine the molar mass of the protein. (18) A solution is prepared by mixing 10.0 g of sodium sulfate with 250 ml of water at 25 ºC. The density of the solution is 1.10 g/ml. (a) Calculate the vapour pressure of the solution at 25 ºC. (b) Determine the boiling point and the freezing point of this solution. (c) Calculate the osmotic pressure of this solution. (19) A solution is prepared by mixing 5.00 g of caffeine (C 8 H 10 N 4 O 2 ) with 250 ml of water at 25 ºC. The density of the solution is 1.05 g/ml. (a) Calculate the vapour pressure of the solution at 25 ºC. (b) Determine the boiling point and the freezing point of this solution. (c) Calculate the osmotic pressure of this solution. Answers: (1) 22.5 mm Hg (2) 90.6 mm Hg (3) 48.5 g (4) mm Hg (5) 177 g/mol (6) 181 g/mol (7) Pentane and hexane would form the most ideal solution since both molecules are non polar and similar and the intermolecular forces are weak. Propanol and propane would not form an ideal solution because propanol is polar and propane is non polar. Methanol and water would not form an ideal solution, even though both substances are polar and similar, because the intermolecular forces are strong due to hydrogen bonding. (8) (a) strong electrolyte (b) weak electrolyte (c) non electrolyte (d) weak electrolyte (e) strong electrolyte (f) non electrolyte (g) strong electrolyte (h) weak electrolyte (9) 0.21 ºC (10) 0.95 ºC (11) T b = ºC T f = ºC (12) T b = ºC T f = ºC (13) (a) T f = 25.0 ºC (b) 92.2 g/mol (14) T b = 5.5 ºC 46.4 g/mol (15) 69.3 atm (16) 56 atm (17) 2.66x10 4 g/mol (18) (a) P solution = mm Hg Tb = ºC Tf = ºC π = 21.9 atm (19) (a) P solution = mm Hg Tb = ºC Tf = ºC π = 2.59 atm