Ch.12 - SolutionsWorksheetSee all chapters
All Chapters
Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds

The 4 Colligative Properties help to explain what happens to a pure solvent as solute is added to it.  

Properties of Solutions

Concept #1: The Colligative Properties. 

The four colligative properties of Boiling Point, Freezing Point, Vapor Pressure and Osmotic Pressure will either increase or decrease with the addition of solute to a pure solvent.  

Example #1: Explain what happens to each of the following properties as solute is added to a pure solvent.

a.  Boiling Point              b.  Freezing Point       

 

c. Osmotic Pressure        d. Vapor Pressure

 

 

Example #2: Which of the following compounds will have the highest boiling point?

a) 0.10 m sucrose

b) 0.10 m CsBrO­­3

c) 0.35 m CH3OH

d) 0.15 m SrBr2

Example #3: Pure water boils at 100oC. What is the expected boiling point of water after the addition of 13.12 g calcium bromide, CaBr2, to 325 g water. Kb = 0.512 oC/m. (MW of CaBr2 is 199.88 g/mol)

Example #4: The vapor pressure of water at 100.0oC is 0.630 atm.  Determine the amount (in grams) of aluminum fluoride, AlF3, (in grams) needed to reduce its vapor pressure to 0.550 atm. (MW of AlF3 is 83.98 g/mol)

Practice: Beta-carotene is the most important of the A vitamins. Calculate the molar mass of Beta-carotene if 25.0 mL of a solution containing 9.88 mg of Beta-carotene has an osmotic pressure of 56.16 mmHg at 30 degrees of Celsius.

Vapor Pressure

Vapor Pressure is achieved by the equilibrium rate of vaporization equaling the rate of condensation. 

Concept #2: Defining Vapor Pressure. 

Example #5: The vapor pressure of pure liquid A is 550 torr and the vapor pressure of pure liquid B is 320 torr at room temperature. If the vapor pressure of a solution containing A and B is 465 torr, what is the mole fraction of A in the solution?

Example #6: Determine the vapor pressure lowering associated with 1.32 m C6H12O6 solution (MW: 180.156 g/mol) at 25oC.

Practice: The following boiling points belong to one of the following compounds: 117°C, 78°C, 34.5°C and 23°C.

CH3-O-CH3                                                                

CH3CH2OH                               

CH3CH2-O-CH2CH3                            

CH3CH2CH2CH2OH

a)  Which boiling point goes with what compound?

b) If each of the following substances were placed in separate sealed clear bottles at room temperature, could you identify one of the substances right away? 

Additional Problems
Calculate the vapor pressure of a solution of 7.35g of aspirin (M = 180.15 g/mol) in 37.1 g of methanol (CH3OH) at 21.2°C. Pure methanol has a vapor pressure of 101 torr at this temperature. Assume that aspirin is NOT an ionic compound. A. 97.6 torr B. 84.3 torr C. 3.44 torr D. 16.7 torr E. 104 torr
Which of the following statements(s) is/are correct. i. A 0.45 m BaCl2 solution will have a lower freezing point than a 0.35 m K 2CrO4 solution. ii. A 0.35 M K2CrO4 solution will have a lower osmotic pressure than a 0.45 M BaCl 2 solution. iii. A 0.45 m K2CrO4 solution will have a higher boiling point than a 0.45 m BaCl 2 solution. A. i only B. ii only C. iii only D. i and ii E. ii and iii
The human eye has an osmotic pressure of 8.00 atm at 37.0 °C. What concentration (in moles/L) of a saline (NaCl) solution will provide an isotonic eyedrop solution? (Isotonic = a solution with equal osmotic pressure.) a) 0.0785 b) 0.157 c) 0.314 d) 0.786 e) 0.942
Assume you add 10 mL of water in an evacuated and sealed container held at 25°C. Which of the following would decrease the vapor pressure? I) adding a nonvolatile solute II) halving the size of the container III) removing some liquid 1. I and II 2. II only 3. I and III 4. I, II, and III 5. I only 6. III only 7. II and III
A compound is found to have a molar mass of 598 g/mol. If 35.8 mg of the compound is dissolved in enough water to make 175 mL of solution at 25°C, what is the osmotic pressure of the resulting solution? A. 3.42 torr B. 6.36 torr C. 5.01 torr D. 5.99 torr E. 8.36 torr    
What is the vapor pressure of a solution made by dissolving 48.4 g of glucose (C6H12O6) in 202.8 g of water at 22 oC. The vapor pressure of pure water at 22 oC is 92.50 mm Hg. A. 2.156 mm Hg B. 74.68 mm Hg C. 17.82 mm Hg D. 58.81 mm Hg E. 90.34 mm Hg
Water typically flows from a ______________solution to a ____________solution: A. Hypertonic; hypotonic B. Hypotonic; hypertonic C. Isotonic; isotonic D. Hypertonic; isotonic
What is the ideal van't Hoff factor for Mg(NO2)2? a) 2 b) 3 c) 4 d) 6 e) 7
Identify the correct van't Hoff factors for each compound.          CaSO 4              NiHPO4               SnF 2Br2 A.           2                        3                          2 B.           2                        2                          3 C.           4                        4                          4 D.            5                       2                          5 E.            2                       2                          5
An aqueous solution at 25°C contains 35 grams of a non-ionizing solute with MW = 83.1 g/mol. The total mass of the solution is 215 grams. The vapor pressure of pure water at 25°C is 23.76 torr. What is the vapor pressure of the solution? A. 23.36 torr B. 23.76 torr C. 0.96 torr D. 2.96 torr E. 22.8 torr
A 0.86% by mass solution of NaCl is called "physiological saline" because its osmotic pressure is equal to that of the solution in the blood cells. Calculate the osmotic pressure of this solution at normal body temperature (37°C). Note that the density of the saline solution is 1.005 g/mL.   
The osmotic pressure of blood at normal body temperature of 37°C is 7.65 atm. Sometimes it is necessary to add a saline (NaCl) solution by intravenous injection to a patient in the emergency room. What should be the concentration of the NaCl solution (in g/L) so that it will have the same osmotic pressure as the blood at 37°C? a. none of the other answers is even close (within 10% error) b. 4.4 c. 2.2 d. 8.8 e. 17.6
Which statement is false? A) The vapor pressure of a solvent over a solution decreases as its mole fraction increases. B) The solubility of a gas increases as the temperature decreases. C) The vapor pressure of a solvent over a solution is less than that of pure solvent.  D) The greater the pressure of a gas over a solution the greater its solubility. E) Ionic solutes dissociate in solution causing an enhancement off all colligative properties.
The vapor pressure of pure ethanol [CH 3OH] at room temperature is 160.00 torr. What mole fraction of glycerol [C3H5(OH)3], a non volatile solute, is required to lower the vapor pressure to 86.00 torr at room temperature? A. 0.416 B. 0.462 C. 0.538 D. 0.584
Below is a U-tube where there are equal volume solution of 0.2M NaCL and 0.1M CaCl2 seperated by a membrance that only allows water through. In which direction will there be net movement of water? left    or   right
 A 0.100 m MgSO4 solution has a freezing point of -0.23°C. What is the van't Hoff factor for this solution? Kf = 1.86°C/m. A) 0.62 B) 1.0 C) 1.2 D) 2.0 E) 4.0
Identify the solute with the highest expected Van't Hoff factor. A) AlBr 3 B) KBr C) C 6 H 8 O 6 D) MgCl 2 E) NH 4 Cl
A solution of urea [(NH2)2CO] (MM: 60 g/mol) in water has a vapor pressure 2.50 mmHg less than that of pure water at 30°C (The vapor pressure of water at 30°C is 31.8 mmHg). a. What is the mole fraction of urea in this solution?     b. How many grams of urea does this correspond to?  
What is the expected Van’t Hoff factor for K 2CO3? A.  1                B.  2                 C.  3              D.  5                E.  6
The vapor pressure of pure acetone (CH 3COCH3) at 30°C is 240 torr. If salt (NaCl) is dissolve into a sample of acetone until the total vapor pressure of the mixture at 30°C is 180 torr, what is the mol fraction of acetone? 1. 0.2 2. 0.25 3. 0.8 4. 0.75
Kf = 1.86°C/m for water. We observe the freezing points of four different aqueous solutions as follows: Solution A freezes at -0.10°C Solution B freezes at -4.00°C Solution C freezes at -10.00°C; and Solution D freezes at -13.00°C. In each solution, the solute is a non-volatile non-electrolyte. Which solution should be expected to have the highest boiling point? 1. Solution D 2. Solution B 3. Solution A 4. Solution C  
Water typically flows from a ______________solution to a ____________solution:   A. Hypertonic; hypotonic B. Hypotonic; hypertonic C. Isotonic; isotonic D. Hypertonic; isotonic
If 2.00 mol of glucose (C 6H12O6) is dissolved in 0.500 kg of water, what is the vapor pressure of the solution? The vapor pressure of water at 25oC is 23.8 torr. A. 23.8 torr     B. 25.5 torr      C.  8.70 torr     D. 22.2 torr     E. 1.60 torr
If substance X has a vapor pressure of 600 torr at room temperature and substance Y has a vapor pressure of 120 torr at room temperature, what would be the vapor pressure of a mixture of 1 mole of X with 3 mole of Y? A. 240 torr B. 680 torr C. 720 torr D. 960 torr
At 25oC the vapor pressure of pure butane (C4H10, MW = 58.12 g/mol) is p°b = 380.0 torr and the vapor pressure of pure hexane (C6H14, MW = 86.17 g/mol) is p°H = 32.0 torr. What is the total pressure at 25oC when mixing equal grams of butane and hexane?
At 35°C the vapor pressure of pure ethanol (C2H5OH, M = 46.1 g/mol) is pE° = 100.0 torr, and the vapor pressure of pure 1-propanol (C3H7OH, M = 60.1 g/mol) is pP° = 37.6 torr.  A solution at equilibrium at this temperature has a total pressure p = 84.2 torr.  Assuming the solution is ideal, what is the partial pressure of ethanol above the solution?
You have two closed containers with ether. Each container has a total volume of 1L. One container is filled with 750 mL of liquid ether. The other container has 500 mL of liquid ether. How does the partial pressure of the ether in the gas phase above the liquid compare in the two containers?  A. It is the same in both containers. B. It is higher in the container with 750 mL. C. It is higher in the container with 500 mL.
What is the vapor pressure  of a solution made by dissolving 79.3 g of glycerol (C3H8O3) in 123.8 g of water? The vapor pressure of water at 26  oC is 25.2 mmHg. A. 9.84 mmHg B. 15.4 mmHg C. 2.81 mmHg D. 22.4 mmHg E. 3.16 mmHg
(Hint: If you dont know where to start, try assuming you have 100g total of solution.) Consider two liquids A and B. The vapor pressure of pure A (molecular weight = 50 g/mol) is 225 torr at 25°C and the vapor pressure of pure B (molecular weight = 75 g/mol) is 90 torr at the same temperature. What is the total vapor pressure at 25°C of a solution that is 25% A amd 75% B by weight? 1. 76 torr 2. 225 torr 3. 335 torr 4. 203 torr 5. 135 torr 6. 191 torr 7. 108 torr 8. 115 torr 9. 124 torr    
The vapor pressure of pure water (H2O) at 30 °C is 40 torr. If salt (NaCl) is dissolved into a sample of water until the total vapor pressure of the mixture at 30 °C is 32 torr, what is the mol fraction of  salt? 1. 0.2 2. 0.5 3. 0.8 4. 0.65 5. 0.35
The van't Hoff factors are a function of the concentration and are often lower than the theoretical value. Would you expect a larger or smaller deviation from the theoretical value as a solution gets more concentrated? Explain.
Red blood cells contain Na+ ions, K+ ions, and water. If we place some red blood cells into a beaker full of pure water, what will happen to them? they will swell and burst they will wiggle around rapidly nothing they will shrivel and collapse
Explain why the lower vapor pressure for a solution containing a nonvolatile solute results in a higher boiling point and lower melting point compared to the pure solvent.
What are colligative properties?
Three 1.0-L flasks, maintained at 308 K, are connected to each other with stopcocks. Initially the stopcocks are closed. One of the flasks contains 1.3 atm of N2, the second 3.6 g of H2O, and the third, 0.40 g of ethanol, C2H6O. The vapor pressure of H2O at 308 K is 42 mmHg and that of ethanol is 102 mmHg. The stopcocks are then opened and the contents mix freely.What is the pressure?
A root cellar is an underground chamber used to store fruits, vegetables, and even meats. In extreme cold, farmers put large vats of water into the root cellar to prevent the fruits and vegetables from freezing.Explain why this works.
Which solution has the highest boiling point?
The osmotic pressure of 0.013 M aqueous solution of CaCl2 is found to be 0.693 atm at 25 oC.Calculate the vant Hoff factor, i, for the solution.
You may want to reference (Pages 593 - 607) Section 13.6 while completing this problem.Calculate the vapor pressure at 25 oC of a solution containing 55.5 g ethylene glycol (HOCH2CH2OH) and 280.2 g water. The vapor pressure of pure water at 25 oC is 23.8 torr.
You may want to reference (Pages 593 - 607) Section 13.6 while completing this problem.A solution containing ethylene glycol and water has a vapor pressure of 7.86 torr at 10 oC. Pure water has a vapor pressure of 9.21 torr at 10 oC. What is the mole fraction of ethylene glycol in the solution?
You may wantto reference (Pages 608 - 608) Section 13.7 while completing this problemA solution of benzene (C6H6) and toluene (C7H8) is 26.0 % benzene by mass. At 25oC the vapor pressures of pure benzene and pure toluene are 94.2 and 28.4 torr, respectively.Assuming ideal behavior, calculate the vapor pressure of benzene in the mixture.
You may wantto reference (Pages 608 - 608) Section 13.7 while completing this problemA solution of benzene (C6H6) and toluene (C7H8) is 26.0 % benzene by mass. At 25oC the vapor pressures of pure benzene and pure toluene are 94.2 and 28.4 torr, respectively.Assuming ideal behavior, calculate the total pressure above the solution.
You may wantto reference (Pages 608 - 608) Section 13.7 while completing this problemA solution of benzene (C6H6) and toluene (C7H8) is 26.0 % benzene by mass. At 25oC the vapor pressures of pure benzene and pure toluene are 94.2 and 28.4 torr, respectively.Assuming ideal behavior, calculate the mass percent of benzene in the vapor.
You may wantto reference (Pages 608 - 608) Section 13.7 while completing this problemA solution of benzene (C6H6) and toluene (C7H8) is 26.0 % benzene by mass. At 25oC the vapor pressures of pure benzene and pure toluene are 94.2 and 28.4 torr, respectively.Assuming ideal behavior, calculate the vapor pressure of toluene in the mixture.
You may wantto reference (Pages 608 - 608) Section 13.7 while completing this problemA solution of benzene (C6H6) and toluene (C7H8) is 26.0 % benzene by mass. At 25oC the vapor pressures of pure benzene and pure toluene are 94.2 and 28.4 torr, respectively.Assuming ideal behavior, calculate the mass percent of toluene in the vapor.
What is the effect of a nonvolatile solute on the vapor pressure of a liquid? Why is the vapor pressure of a solution different from the vapor pressure of the pure liquid solvent?
You may wantto reference (Pages 608 - 608) Section 13.7 while completing this problemA solution of benzene (C6H6) and toluene (C7H8) is 26.0 % benzene by mass. At 25oC the vapor pressures of pure benzene and pure toluene are 94.2 and 28.4 torr, respectively.Why is the composition of the vapor different from the composition of the solution?
What is the effect on vapor pressure of a solution with particularly strong solute-solvent interactions? With particularly weak solute-solvent interactions?
You may want to reference (Pages 608 - 608) Section 13.7 while completing this problem.A solution contains 0.115 mol H2O and an unknown number of moles of sodium chloride. The vapor pressure of the solution at 30oC is 25.5 torr. The vapor pressure of pure water at 30oC is 31.5 torr. Calculate the number of moles of sodium chloride in the solution.
A beaker contains 100.0 mL of pure water. A second beaker contains 100.0 mL of seawater. The two beakers are left side by side on a lab bench for one week. At the end of the week, the liquid level in both beakers has decreased. However, the level has decreased more in one of the beakers than in the other.Which one level has decreased more?
A solution of methanol and water has a mole fraction of water of 0.312 and a total vapor pressure of 211 torr at 39.9oC. The vapor pressures of pure methanol and pure water at this temperature are 256 torr and 55.3 torr, respectively.Is the solution ideal?
At 35 oC the vapor pressure of acetone, (CH3 )2 CO, is 361 torr, and that of chloroform, CHCl3, is 301 torr. Acetone and chloroform can form weak hydrogen bonds between one another; the chlorines on the carbon give the carbon a sufficient partial positive charge to enable this behavior: A solution composed of an equal number of moles of acetone and chloroform has a vapor pressure of 250 torr at 35 oC.What would be the vapor pressure of the solution if it exhibited ideal behavior?
The vapor pressure of pure water at 60oC is 149 torr. The vapor pressure of water over a solution at 60 oC containing equal numbers of moles of water and ethylene glycol (a nonvolatile solute) is 67 torr. Is the solution ideal according to Raoults law?
The following diagram shows the vapor pressure curves of a volatile solvent and a solution of that solvent containing a nonvolatile solute. Which line represents the solution?
Calculate the vapor pressure of water above a solution prepared by adding 23.0 g of lactose (C12 H22 O11 ) to 200.0 g of water at 338 K. (Vapor-pressure of water at 338 K 187.5 torr.)
Calculate the mass of propylene glycol (C3 H8 O2 ) that must be added to 0.350 kg of water to reduce the vapor pressure by 2.88 torr at 40 oC (PH2O at 40 C = 55.3).
At 63.5oC the vapor pressure of H2O is 175 torr, and that of ethanol (C2H5OH) is 400 torr. A solution is made by mixing equal masses of H2O and C2H5OH.Assuming ideal-solution behavior, what is the vapor pressure of the solution at 63.5oC?
Calculate the vapor pressure at 25 oC of an aqueous solution that is 5.55 % NaCl by mass.
An aqueous CaCl2 solution has a vapor pressure of 82.1 mmHg at 50 oC. The vapor pressure of pure water at this temperature is 92.6 mmHg.What is the concentration of CaCl2 in mass percent?
Does adding 1 mol of NaCl to 1 kg of water lower the vapor pressure of water to the same extent, a lesser extent, or a greater extent than adding 1 mol of C6H12O6 to 1 kg of water?
The vapor above an aqueous solution contains 19.1 mg water per liter at 25 oC.Assuming ideal behavior, what is the concentration of the solute within the solution in mole percent?
You may want to reference (Pages 542 - 552) Section 13.5 while completing this problem.Calculate the vapor pressure of water above a solution prepared by dissolving 28.5 g of glycerin (C3H8O3) in 135 g of water at 343 K. (The vapor pressure of water at 343 K is 233.7 torr.)
You may want to reference (Pages 542 - 552) Section 13.5 while completing this problem.Calculate the mass of ethylene glycol (C2H6O2) that must be added to 1.00 kg of ethanol (C2H5OH) to reduce its vapor pressure by 9.00 torr at 35 oC . The vapor pressure of pure ethanol at 35 oC is 1.00 102 torr .
A solution of a nonvolatile solute in water has a boiling point of 380.4 K .Calculate the vapor pressure of water above this solution at 338 K. The vapor pressure of pure water at this temperature is 0.2467 atm.
The density of a 0.438 M solution of potassium chromate (K2 CrO4) at 298 K is 1.063 g/mL.Calculate the vapor pressure of water above the solution. The vapor pressure of pure water at this temperature is 0.0313 atm. Assume complete dissociation.
The vapor above a mixture of pentane and hexane at room temperature contains 35.5% pentane by mass. What is the mass percent composition of the solution? Pure pentane and hexane have vapor pressures of 425 torr and 151 torr, respectively, at room temperature.
A solution of 75.0 g of benzene (C6H6) and 75.0 g of toluene (C7H8) has a total vapor pressure of 80.9 mmHg at 303 K. Another solution of 100.0 g benzene and 50.0 g toluene has a total vapor pressure of 93.9 mmHg at this temperature.Find the vapor pressure of pure toluene at 303 K.
A solution of 75.0 g of benzene (C6H6) and 75.0 g of toluene (C7H8) has a total vapor pressure of 80.9 mmHg at 303 K. Another solution of 100.0 g benzene and 50.0 g toluene has a total vapor pressure of 93.9 mmHg at this temperature.Find the vapor pressure of pure benzene 303 K.
Two beakers are placed in a sealed box at 25 oC. One beaker contains 35.0 mL of a 5.5×10−2 M aqueous solution of a nonvolatile nonelectrolyte. The other beaker contains 35.0 mL of a 4.0×10−2 M aqueous solution of NaCl. The water vapor from the two solutions reaches equilibrium.In which beaker does the solution level rise, and in which one does it fall?
Two beakers are placed in a sealed box at 25 oC. One beaker contains 35.0 mL of a 5.5×10−2 M aqueous solution of a nonvolatile nonelectrolyte. The other beaker contains 35.0 mL of a 4.0×10−2 M aqueous solution of NaCl. The water vapor from the two solutions reaches equilibrium.What is the volume in the beaker with the aqueous solution of NaCl when equilibrium is attained, assuming ideal behavior?
Two beakers are placed in a sealed box at 25 oC. One beaker contains 35.0 mL of a 5.5×10−2 M aqueous solution of a nonvolatile nonelectrolyte. The other beaker contains 35.0 mL of a 4.0×10−2 M aqueous solution of NaCl. The water vapor from the two solutions reaches equilibrium.What is the volume in the beaker with the aqueous solution of a nonvolatile nonelectrolyte when equilibrium is attained, assuming ideal behavior?
You may want to reference (Pages 593 - 596) Section 13.6 while completing this problem.Determine the vapor pressure of an aqueous ethylene glycol (C2H6O2) solution that is 14.8 % C2H6O2 by mass. The vapor pressure of pure water at 25 oC is 23.8 torr.
Consider two solutions, one formed by adding 10 g of glucose (C6 H12 O6 ) to 1 L of water and the other formed by adding 10 g of sucrose (C12 H22 O11 ) to 1 L of water.Calculate the vapor pressure for the first solution at 20 oC. (The vapor pressure of pure water at this temperature is 17.5 torr.)
Consider two solutions, one formed by adding 10 g of glucose (C6 H12 O6 ) to 1 L of water and the other formed by adding 10 g of sucrose (C12 H22 O11 ) to 1 L of water.Calculate the vapor pressure for the second solution at 20 oC. (The vapor pressure of pure water at this temperature is 17.5 torr.)
A solution contains 4.08 g of chloroform (CHCl3 ) and 9.29 g of acetone (CH3 COCH3 ). The vapor pressures at 35 oC of pure chloroform and pure acetone are 295 torr and 332 torr, respectively.Assuming ideal behavior, calculate the vapor pressure of chloroform.
A solution contains 4.08 g of chloroform (CHCl3 ) and 9.29 g of acetone (CH3 COCH3 ). The vapor pressures at 35 oC of pure chloroform and pure acetone are 295 torr and 332 torr, respectively.The experimentally measured total vapor pressure of the solution at 35 oC was 312 torr. Is the solution ideal?
A solution contains 4.08 g of chloroform (CHCl3 ) and 9.29 g of acetone (CH3 COCH3 ). The vapor pressures at 35 oC of pure chloroform and pure acetone are 295 torr and 332 torr, respectively.Assuming ideal behavior, calculate the vapor pressure of acetone.
A solution contains 4.08 g of chloroform (CHCl3 ) and 9.29 g of acetone (CH3 COCH3 ). The vapor pressures at 35 oC of pure chloroform and pure acetone are 295 torr and 332 torr, respectively.Assuming ideal behavior, calculate the total vapor pressure above the solution.
A "canned heat" product used to warm buffet dishes consists of a homogeneous mixture of ethanol (C2 H5 OH) and paraffin, which has an average formula of C24 H50.What mass of C2 H5 OH should be added to 630 kg of the paraffin to produce 8 torr of ethanol vapor pressure at 35 oC? The vapor pressure of pure ethanol at 35 oC is 100 torr.
A solution contains 0.111 mol H2O and an unknown number of moles of sodium chloride. The vapor pressure of the solution at 30 oC is 25.7 torr. The vapor pressure of pure water at this temperature is 31.8 torr.Calculate the number of grams of sodium chloride in the solution. (Hint: Remember that sodium chloride is a strong electrolyte.)
The vapor pressure of carbon tetrachloride, CCl4, is 0.354 atm and the vapor pressure of chloroform, CHCl3, is 0.526 atm at 316 K. A solution is prepared from equal masses of these two compounds at this temperature.Calculate the mole fraction of the chloroform in the vapor above the solution.
The vapor pressure of carbon tetrachloride, CCl4, is 0.354 atm and the vapor pressure of chloroform, CHCl3, is 0.526 atm at 316 K. A solution is prepared from equal masses of these two compounds at this temperature.If the vapor above the original solution is condensed and isolated into a separate flask, what would the vapor pressure of chloroform be above this new solution?
You may want to reference (Pages 542 - 552)Section 13.5 while completing this problem.The vapor pressure of benzene, C6H6, is 100.0 torr at 26.1 oC. Assuming Raoult’s law is obeyed, how many moles of a nonvolatile solute must be added to 100.0 mL of benzene to decrease its vapor pressure by 10.0% at 26.1 oC? The density of benzene is 0.8765 g/cm3.
A solution contains equal amounts (in moles) of liquid components A and B. The vapor pressure of pure A is 100 mmHg and that of pure B is 200 mmHg. The experimentally measured vapor pressure of the solution is 120 mmHg. What are the relative strengths of the solute–solute, solute–solvent, and solvent–solvent interactions in this solution?
The normal boiling point of ethanol, CH3CH2OH, is 78.4 C. When 8.65 g of a soluble nonelectrolyte is dissolved in 100.0 g of ethanol at that temperature, the vapor pressure of the solution is 7.40 102 torr. What is the molar mass of the solute?
Lauryl alcohol is a nonelectrolyte obtained from coconut oil and is used to make detergents. A solution of 7.20 g of lauryl alcohol in 0.200 kg of benzene freezes at 4.5 oC. You may want to reference (Pages 542 - 552)Section 13.5 while completing this problem.What is the approximate molar mass of lauryl alcohol?
Lysozyme is an enzyme that breaks bacterial cell walls. A solution containing 0.150 g of this enzyme in 210 mL of solution has an osmotic pressure of 0.953 torr at 25 oC.What is the molar mass of lysozyme?
A dilute aqueous solution of an organic compound soluble in water is formed by dissolving 2.35 g of the compound in water to form 0.250 L solution. The resulting solution has an osmotic pressure of 0.605 atm at 25 oC. You may want to reference (Pages 542 - 552) Section 13.5 while completing this problem.Assuming that the organic compound is a nonelectrolyte, what is its molar mass?
A solution contains 11.05 g of unknown compound dissolved in 50.0 mL of water. (Assume a density of 1.00 g/mL for water.) The freezing point of the solution is -3.48 oC. The mass percent composition of the compound is 60.98% C, 11.94% H, and the rest is O.What is the molecular formula of the compound?
The osmotic pressure of a solution containing 2.10 g of an unknown compound dissolved in 175.0 mL of solution at 25 oC is 1.93 atm . The combustion of 24.02 g of the unknown compound produced 28.16 g CO2 and 8.640 g H2O.What is the molecular formula of the compound (which contains only carbon, hydrogen, and oxygen)?
A metal, M, of atomic weight 96 reacts with fluorine to form a salt that can be represented as MFx. In order to determine x and therefore the formula of the salt, a boiling point elevation experiment is performed. A 9.18-g sample of the salt is dissolved in 100.0 g of water and the boiling point of the solution is found to be 374.38 K.Find the formula of the salt. Assume complete dissociation of the salt in solution.
Carbon disulfide (CS2 ) boils at 46.30 oC and has a density of 1.261 g/mL.When 5.40 g of a nondissociating unknown is dissolved in 50.0 mL of CS2, the solution boils at 47.08 oC. What is the molecular weight of the unknown?
A lithium salt used in lubricating grease has the formula LiCn H2n + 1 O2. The salt is soluble in water to the extent of 0.036 g per 100 g of water at 25 oC. The osmotic pressure of this solution is found to be 57.1 torr.Assuming that molality and molarity in such a dilute solution are the same and that the lithium salt is completely dissociated in the solution, determine an appropriate value of n in the formula for the salt.
You may want to reference (Pages 593 - 607) Section 13.6 while completing this problem.Calculate the osmotic pressure (in atmospheres) of a solution containing 2.10 g ethylene glycol (C2H6O2) in 53.0 mL of solution at 25oC.
What is osmosis? What is osmotic pressure?
Seawater contains 35.1 g of salts for every liter of solution. You may want to reference (Pages 542 - 552) Section 13.5 while completing this problem.Assuming that the solute consists entirely of NaCl (in fact, over 90% of the salt is indeed NaCl), calculate the osmotic pressure of seawater at 20 oC .
You may want to reference (Pages 609 - 610) Section 13.6 while completing this problem.What mass of sucrose (C12H22O11) should be combined with 501 g of water to make a solution with an osmotic pressure of 8.55 atm at 300 K ? (Assume the density of the solution to be equal to the density of the solvent.)
Measured and Expected vant Hoff Factors for Several Substances at 25 oC Concentration Compound 0.100 m 0.0100 m 0.00100 m Expected Value Sucrose 1.00 1.00 1.00 1.00 NaCl 1.87 1.94 1.97 2.00 K2SO4 2.32 2.70 2.84 3.00 MgSO4 1.21 1.53 1.82 2.00 Based on the data given in the table, which solution would give the larger freezing-point lowering, a 0.030 m solution of NaCl or a 0.020 m solution of K2SO4?
Suppose you had a balloon made of some highly flexible semipermeable membrane. The balloon is filled completely with a 0.2 M solution of some solute and is submerged in a 0.1 M solution of the same solute: Initially, the volume of solution in the balloon is 0.25 L. Assuming the volume outside the semipermeable membrane is large, as the illustration shows, what would you expect for the solution volume inside the balloon once the system has come to equilibrium through osmosis?
You may want to reference (Pages 542 - 552) Section 13.5 while completing this problem.Arrange the following aqueous solutions, each 10% by mass in solute, in order of decreasing boiling point: glucose (C6H12O6), sucrose (C 12H22O11), sodium nitrate (NaNO3).
List the following aqueous solutions in order of decreasing boiling point. 0.120 m glucose, 0.050 m   LiBr, 0.050 m   Zn ( NO3 )2.
You may want to reference (Pages 542 - 552) Section 13.5 while completing this problem.List the following aqueous solutions in order of decreasing freezing point: 0.040 m glycerin (C3H8O3), 0.020 m potassium bromide (KBr), 0.030 m phenol (C6H5OH).
What is the osmotic pressure of a solution formed by dissolving 44.3 mg of aspirin (C9 H8 O4 ) in 0.358 L of water at 25 oC?
Is the osmotic pressure of a 0.10 M solution of NaCl greater than, less than, or equal to that of a 0.10 M solution of KBr?
Does a 0.10 m aqueous solution of NaCl have a higher boiling point, a lower boiling pointpoint, or the same boiling point as a 0.10 m aqueous solution of C6H12O6?
Osmosis is the process of a solvent moving from one compartment to another, across a semipermeable membrane, toward higher solute concentration. Osmotic pressure is generated at equilibrium due to the different heights of liquid on either side of the membrane and is equivalent to the pressure needed to equalize the fluid levels across the membrane.If the pure water in the left arm of the U-tube is replaced by a solution more concentrated than the one in the right arm, what will happen?
Osmosis through red blood cell walls. If water moves out of the red blood cell, it shrivels (crenation); if water moves into the red blood cell, it will swell and may burst (hemolysis).If the fluid surrounding a patient’s red blood cells is depleted in electrolytes, is crenation or hemolysis more likely to occur?
You may want to reference (Pages 542 - 552)Section 13.5 while completing this problem.Proteins frequently form complexes in which 2, 3, 4 or even more individual proteins (“monomers”) interact specifically with each other via hydrogen bonds or electrostatic interactions. The entire assembly of proteins can act as one unit in solution, and this assembly is called the “quaternary structure” of the protein. Suppose you discover a new protein whose monomer molar mass is 25,000 g/mol. You measure an osmotic pressure of 0.0916 atm at 37 oC for 7.20 g of the protein in 10.00 mL of an aqueous solution. How many protein monomers form the quaternary protein structure in solution? Treat the protein as a nonelectrolyte.
You may want to reference (Pages 542 - 552)Section 13.5 while completing this problem.Which of the following actions will raise the osmotic pressure of a solution?
You may want to reference (Pages 542 - 552)Section 13.5 while completing this problem.Which aqueous solution will have the lowest freezing point?
Explain why drinking seawater results in dehydration.
Which term describes the energy change associated with molecules that have some movement past each other to molecules that have no interactions with other molecules? A. ΔHvap            B. ΔH fus            C. ΔH cond            D. C p(gas)            E. C p(liquid)
75.225 g of an unknown compound is dissolved in 455.00 g of H 2O. A scientist measures that the solution now freezes at -9.26°C. Assuming that the compound is NOT ionic, what is the molecular weight of the compound kf = 1.86°Cm-1.
For an aqueous solution of HF, determine the van't Hoff factor assuming: i) 0% ionization ii) 100% ionization
The vapor pressure of all liquids1. is the same at 100°C.2. increase with volume of liquid present.3. is the same at their freezing points.4. increases with temperature.5. decreases with the increasing volume of the container. 
If all of the following solutions were held at 25.00 oC and the osmotic pressure were carefully monitored, which of the solutions would have the highest osmotic pressure?A. 1.0 M glucose, C6H12O6B. 0.35 M CaCl2C. 0.25 M Na2SO4D. 0.30 M AlCl3E. 0.52 M KCl
A and B are volatile miscible liquids. The partial pressures of A and B and the total pressure above a solution of A and B are given in the diagram below as a function of XA, the mole fraction of A, and at a temperature T = 40.0 °C. Based on the diagram answer the following questions. a) Do A and B form an ideal liquid solution (yes or no, and a brief justification for your answer)? b) What is pB°, the vapor pressure of pure B, at T = 40.0 °C?
The osmotic pressure of a solution containing 2.46 mg of an unknown protein in 50.0 mL of solution is 1.66 atm at 25 oC? Find the molar mass of the unknown protein. a. 0.766 g/molb. 0.587 g/molc. 0.725 g/mold. 0.487 g/mole. 0.357 g/mol 
2.09 g of copper II nitrate (Cu(NO 3)2, MW = 187.56 g/mol) is dissolved in water, to form a solution with final volume V = 250.0 mL. What is the osmotic pressure of the solution relative to pure water? Assume T = 25.0 °C in your calculations, and give your final answer in units of atm.
An aqueous CaCl2 solution has a vapor pressure of 106.4 mmHg at 55.0 oC. The vapor pressure of pure water at this temperature is 118.0 mmHg. What is the concentration of CaCl2 in mass percent?A. 40.2%B. 25.3%C. 18.3%D. 15.3%E. 21.2%
Identify the solute with the highest van't Hoff factor.A. Non-electrolyteB. NaClC. MgSO4D. MgCl2E. FeCl3
At 25°C the vapor pressure of pure hexane (C 6H14) is 0.198atm, while that of pure heptane (c7H16) is 0.060 atm.Calculate the vapor pressure of a mixture of 17.2 g of hexane and 25.0 g of heptane at 25°C, assuming hexane and heptane form an ideal solution. (a) 0.0546 atm(b) 0.121 atm(c) 0.129 atm(d) 0.137(e) none of these
The boiling point of an aqueous 1.83 m salt solution is 102.5°C. Determine the value of the van't Hoff factor for this solute if the Kb for water is 0.512°C/m.A. 3.0B. 3.6C. 1.8D. 2.7E. 2.3
1.53 x 10‐2 M solutions of CaCl 2 and urea at 25°C have osmotic pressures of 0.926 and 0.375 atm, respectively. Calculatle the van’t Hoff factor for the CaCl2 solution.A) 1B) 2C) 2.46D) 2.76E) 3 
Arrange the following aqueous solutions in order of decreasing freezing point (left to right):I) 0.1 m Na3PO4,II) 0.1 m NaCl,III) 0.1 m MgCl2,IV) 0.1 m C6H12O6,V) 0.1 m SnCl4Highest FP            Lowest FPA) I < II < III < IV < VB) V < IV < III < II < IC) I < V < II < III < IVD) IV < II < III < I < VE) IV < I < III < II < V
The osmotic pressure of a 0.010 M potassium iodide (KI) solution at 25 °C is 0.465 atm. Calculate the van’t Hoff factor for KI at this concentration.
A mixture of ethanol and 1‐propanol behaves ideally at 36°C and is in equilibrium with its vapor. If the mole fraction of ethanol in the solution is 0.67, calculate its mole fraction in the vapor phase at this temperature. (The vapor pressures of pure ethanol and 1‐propanol at 36°C are 108 and 40.0 mmg Hg, respectively.)A) 0.15B) 0.33C) 0.67D) 0.73E) 0.84
The vapor pressure of pure ethanol (C 2H5OH) is 44 mmHg and the vapor pressure of pure methanol (CH3OH) at the same temperature is 94 mmHg. A mixture of 48 g of methanol and 69 g of ethanol forms an ideal solution. Calculate the combined vapor pressure of the resulting solution.A) 1 atmB) 138 mmHgC) 69 mmHgD) 47 mmHgE) 22 mmHg
Lauryl alcohol, a component of coconut oil, is used to make detergents. A solution of 5.00 g of lauryl alcohol in 0.100 kg of benzene freezes at 4.1°C. What is the molar mass of lauryl alcohol? Kf (benzene) = 5.12°C/m; Tf (benzene) = 5.50°C.a) 270 g/molb) 13.7 g/molc) 62.4 g/mold) 46.5 g/mole) 183 g/mol
In a(n) _____ solution, red blood cells _____.A) isosmotic, have a normal shape.B) hyperosmotic, have a normal shapeC) isosmotic, lose water and shrivelD) isosmotic, swell and may burstE) none of the above
Rank the following solutions from lowest to highest vapor pressure. To rank items as equivalent, overlap themi) 20 g. of glucose C 6H12O6 in 100ml H2Oii) 10 g. of protassium acetate KC 2H3O2 in 100ml H2Oiii) 20 g. of sucrose C12H22O11 in 100ml H2O
Which of the following solutions will have the largest osmotic pressure?a) 0.50 m C6H12O6b) 0.50 m NaClc) 0.50 m K2SO4d) 0.50 m FeCl3
Which of the following solutions will have the lowest freezing point? a. 0.2M KBrb. 0.4M HNO3c. 0.6M ethanol C2H5OHd. 0.2M K2SO4
The vapor pressures (in torr) of solid and liquid chlorine are given by
A solution of 2.50 g of a nonelectrolyte is dissolved in 10.0 g of water and the solution freezes at -3.720°C. What is the molecular weight of the nonelectrolyte?Kf(H2O) = 1.860°C/ma) 50.0 g/molb) 75.0 g/molc) 100 g/mold) 125 g/mole) 150 g/mol   
Given the Kf of water is 1.86° C/m, which of the following aqueous solutions has the lowest freezing point?a) 0.18 m KClb) 0.15 m Na 2SO4c) 0.12 m Ca(NO3)2d) pure watere) 0.20 m C2H6O2 (ethylene glycol)
Which of the following choices shows the correct arrangement of the given aqueous solutions in order of lowest freezing point to highest freezing point?   I) 0.10 m HBrII) 0.35 m KOHIII) 0.20 m MgCl2 IV) 0.15 m HF? a) IV, I, III, IIb) I, II, III, IVc) III, I, IV, IId) II, III, IV, Ie) some other order
A semipermeable membrane is placed between the following solutions. Which solution will decrease in volume? a. Solution A: 1.31% (m/v) starch b. Solution B: 7.48% (m/v) starch
A semipermeable membrane is placed between the following solutions. Which solution will increase in volume? a. Solution A: 6.75% NaCl b. Solution B: 11.7% NaCl
The density of toluene (C6H5CH3) at 25°C = 0.862 g/mL, and its vapor pressure at 25°C = 28.44 torr. At 25°C, the vapor pressure of toluene above a solution of naphthalene (C10H8) in 500.0 mL toluene is found to be 27.92 torr. How many grams of naphthalene are present in the solution?
Arrange the following aqueous solutions in order of increasing boiling points: 0.050 m Mg(NO3)2; 0.10m ethenol; 0.090m NaCla. ethanol <Mg(NO3)2 < NaClb. Mg(NO3)2 < ethanol < NaClc. Mg(NO3)2 <NaCl < ethanold. NaCl <ethanol <Mg(NO3)2e. ethanol <NaCl <Mg(NO3)2
Using freezing point depression to find molecular weightMass of Lauric Acid (g)                                                                     8.003Mass of benzoic Acid (g)                                                                   1.010Freezing temperature of pure lauric acid (C°)                                   43.84Freezing temperature of the benzoic acid-lauric acid mixture (C°)   39.05a. Calculate molality (m), in mol/kg, using the formula Δt = Kf  * m. The Kf value for lauric acid is 3.9°C•kg/mol. b. Calculate moles of benzoic acid solute, using the molality and the mass (in kg) of lauric acid solvent.  c. Calculate the experimental molecular weight of benzoic acid, in g/mol.  d. Determine the accepted molecular weight of benzoic acid from its formula, C 6H5COOH. e. Calculate the percent discrepancy between the experimental and accepted values.   
Which of the following is not a colligative property?a. osmotic pressureb. Henry’s Lawc. vapor pressure loweringd. freezing point depressione. boiling point elevation
A 0.25 gram sample of an unknown compound (a nonelectrolyte where i = 1) is dissolved in 225 mL of water. This solution is found to have an osmotic pressure of 342 torr at a temperature of 28°C. What is the molar mass of the unknown compound?
Acetone, CH3COCH3 (58 g/mol), and ethyl acetate, C2H5COOCH3 (88 g/mol), are common organic solvents. At 30°C, the vapor pressure of acetone is 285 torr, and the vapor pressure of ethyl acetate is 120 torr. What is the vapor pressure at 30°C of a solution prepared by dissolving 11 g of ethyl acetate into 29 g of acetone?
Rank the following solutions from lowest to highest vapor pressure. To rank items as equivalent, overlap them.(1) 10.0 g of potassium acetate KC 2H3O2 in 100.0 mL of water  (2) 20.0 g of sucrose (C12H22O11) in 100.0 mL of water  (3) 20.0 g of glucose (C 6H12O6) in 100.0 mL of water
 When a nonvolatile solute is added to a volatile solvent, the solution vapor pressure, the boiling point ___________________ the freezing point__________ and the osmotic pressure across a semi permeable membrane _________________________. a) decreases, increases. decreases, increasesb) increases, increases, decreases, increasesc) increases, decreases, increases, decreasesd) decreases, decreases, increases, decreasese) decreases; increases. decreases. decreases
Calculate the mole fraction of methanol in the vapor phase at 63.° C for an ideal solution containing 25.0 g of pure methanol (CH3OH, 32.0 g/mol) and 75.0 g of pure ethanol (CH3CH2OH, 46.1 g/mol)). The vapor pressure of methanol and ethanol at 63.5°C is 717.2 mmHg and 400.0 mmHg, respectively. a) 0.463b) 0.642c) 0.0925d) 0.163e) none of the above
Colligative properties are similar in that they all ________a. lower the activation energy of the solventb. have no effect on the properties of solutionc. describe colloidsd. are due to solvent-solvent chemical interactionse. depend on the number of solute particles in solution
A solution is made by dissolving 40.0 grams of magnesium phosphate (MM = 262.87) in 500 grams of water. The observed boiling point of the solution is 100.50°C, what is the observed Van’t Hoff factor for magnesium phosphate in this solution? The Kb for water is 0.512°C/m.A. 0.025B. 1.6C. 3.2D. 4.8E. 5.0
Which of the following is true for all colligative properties?a) The measurement must be made at constant temperature for all colligative propertiesb) The measurement must be made at constant pressure for all colligative propertiesc) The measurement must be made in a closed containerd) It is the number of particles that is important and not their typee) The intermolecular forces are responsible for the colligative properties
Rank the following aqueous solutions in order of decreasing boiling point.A. 0.020 m NaBr > 0.012 m KCl > 0.005 m SrCl2 > 0.012 m sucroseB. 0.020 m NaBr > 0.005 m SrCl2 > 0.012 m KCl = 0.012 m sucroseC. 0.005 m SrCl2 > 0.012 m KCl > = 0.012 m sucrose > 0.020 m NaBrD. 0.012 m sucrose > 0.012 m KCl > 0.005 m SrCl2 > 0.020 m NaBr
Which of the following solutions will have the highest electrical conductivity?a. 0.10 M Klb. 0.050 M (NH4)2CO3c. 0.10 M KFd. 0.045 M Al2(SO4)3e. 0.10 M KBr
Which of the following aqueous solutions has the lowest freezing point?a. 0.18 m KClb. 0.15 m Na 2SO4c. 0.12 m Ca(NO3)2d. pure watere. 0.20 m C2H6O2 (ethylene glycol)
A 1.00 g sample of Cr(NH 3)4Cl4 (MW = 261.84 g/mol) is dissolved in 25.0 g of water and the freezing point of the solution is -0.85°C. How many ions are produced by the compound? The Kf of water is 1.86 °C /m.A. 2B. 3C. 4D. 5
A solution is 40.0% by volume benzene (C6H6) in carbon tetrachloride at 20°C. The vapor pressure of pure benzene at this temperature is 74.61 mmHg and its density is 0.87865 g/cm3; the vapor pressure of pure carbon tetrachloride is 91.32 mmHg and its density is 1.5940 g/cm3. If this solution is ideal, its total vapor pressure at 20°C isA) 84.64 mmHg.B) 84.30 mmHg.C) 82.96 mmHg.D) 81.63 mmHg.E) 165.93 mmHg.
Which of the following aqueous solutions has the lowest freezing point?a. 2.4 m glucoseb. 1.0 m Na 2CO3c. 0.60 m AlCl3d. 1.5 m HF
Which of the following is not a colligative property?a) vapor pressure loweringb) Henry's Lawc) freezing point depressiond) osmotic pressuree) boiling point elevation
Which statements below are TRUE regarding colligative properties?I) The magnitude depends on the quantity of the solute particles.II) A 0.1 m CaCl 2 aqueous solution has a lower freezing point than a 0.1 m C 12 H 22 O 11 aqueous solution.III) The vapor pressure of a solution is proportional to the mole fraction of solvent in solution. A) II onlyB) III onlyC) both I and IIID) both II and IIIE) I, II and III
Calculate the mass of ethylene glycol (C2H6O2, molar mass = 62.07 g/mol) that must be added to 1.00 kg of ethanol (C2H5OH, molar mass = 46.07 g/mol) to reduce its vapor pressure by 10.0 torr at 35 °C. The vapor pressure of pure ethanol at 35 °C is 100 torr.
A 50.0 g sample of naphthalene (a nonvolatile nonelectrolyte), C 10H8, is dissolved in 100.0 g of benzene, C6H6 at 20 °C. The vapor pressure of pure benzene in 74.6 torr at 20.0 °C. What is the vapor pressure of the solution?a. 57.2b. 58.8c. 59.4d. 60.2e. 60.8
List the following solutions in order of increasing boiling points.(a) 0.60 m NaClO4(aq)   (b) 0.50 m CaBr2(aq)(c) 0.40 m Fe(NO3)3
Which of the following solutes in aqueous solution would be expected to exhibit the largest freezing-point lowering (assuming ideal behavior)?a. 0.1 m MgCl2b. 0.2 m Acetic Acid (CH3CO2H)c. 0.05 m Al2(SO4)3d. 0.1 m NaCle. 0.25 m sucrose (C12H22O12)
The escape of molecules from the surface of a liquid is known as ____.a. condensationb. boilingc. evaporationd. sublimation
A solution is made by dissolving 40.0 grams of magnesium phosphate (MM = 262.87) in 500 grams of water. The observed boiling point of the solution is 100.50°C, what is the observed Van’t Hoff factor for magnesium phosphate in this solution? The Kb for water is 0.512°C/m.A. 0.025B. 1.6C. 3.2D. 4.8E. 5.0
Given that blood exert the same osmotic pressure as a 0.15 M NaCl solution, which of the following could be the contents of the second beaker?a. 0.008 NaClb. 0.15 NaClc. 0.68 NaCl
 A 150.0 mL sample of an aqueous solution at 25°C contains 15.2 mg of an unknown nonelectrolyte compound. If the solution has an osmotic pressure of 8.44 torr, what is the molar mass of the unknown compound?A) 223 g/mol      B) 294 g/mol      C) 448 g/mol      D) 195 g/mol      E) 341 g/mol
Lysozyme is an enzyme that cleaves cell walls. A 0.100 L aqueous solution of lysozyme that contains 75.0 mg of the enzyme has an osmotic pressure of 1.00 torr at 25°C. What is the molecular weight of lysozyme?a. 1.02 x 10 3 g/molb. 1.39 x 10 3 g/molc. 1.06 x 10 5 g/mold. 1.39 x 10 4 g/mole. 1.06 x 10 7 g/mol
You have a solution that contains 25 g of an unknown non-ionizing polymer in a 250 mL solution of chloroform (CHCl3). The osmotic pressure of this solution at 25◦C is found to be 0.056 atm. What is the molecular weight of the unknown solid? A. 43,500 g mol −1B. 1,740 g mol −1C. 10,870 g mol −1D. 3,650 g mol −1E. 41,000 g mol −1
A solution is made by dissolving 0.0150 mol of HF in enough water to make 1.00 L of solution. At 22°C, the osmotic pressure of the solution is 0.443 atm. What is the percent ionization of this acid?
Which aqueous solution would you expect to have the highest boiling point? A. 0.2 M sugarB. All of these solutions would have the same boiling point.C. 0.2 M Na 2SO4D. 0.2 M KCl
How will the osmotic pressure of an aqueous solution change as evaporation occurs? A) The osmotic pressure will increase. B) The osmotic pressure will decrease. C) The osmotic pressure will not change. D) The osmotic pressure will increase or decrease until it equals the vapor pressure of water.
Identify the colligative property.A) vapor pressure loweringB) freezing point depressionC) boiling point elevationD) osmotic pressureE) all of the above
An unknown compound shows an elemental analysis of 40% C, 6.7% H and 53.3% O. When 289.418 g of the unknown compound is dissolved in 1.8 L of water, the freezing point of the solution is lowered by 3.32oC. Assuming that the compound is a nonvolatile, calculate its molar mass and its molecular formula. The freezing point constant, Kf, of water is 1.86 oC/m. 
A red blood cell placed in pure water will swell becausea. the osmotic pressure is greater in the water than in the cell.b. the osmotic pressure is greater in the cell than in the water.c. the osmotic pressure is the same in the cell and the water.d. water moves from a higher osmotic pressure to a lower osmotic pressure.e. the vapor pressure of the water in the cell is greater than the vapor pressure of pure water.
0.150 g of an unknown substance are added to water to make 100.00 mL of solution. The osmotic pressure of the solution is measured to be 477.688 torr at 44.0 oC. What is the molecular weight of the solute? (R= 0.08206 L atm/mol K)A. 8.62 g/molB. 91.34 g/molC. 24.18 g/molD. 67.05 g/molE. 62.08 g/mol  
Identify the solute with the lowest Van't Hoff factor. A) nonelectrolyte B) KI C) MgSO4 D) CaCl2 E) AlCl3
Calculate the mass of urea (molar mass = 60.05 g/mol) that should be dissolved in 191 g of water (molar mass =18.02 g/mol) at 35 °C to produce a solution with a vapor pressure of 37.3 mmHg. (At 35 °C, Pwater = 42.2 mmHg). Show calculations.
Which of the following solutions will have the  lowest freezing point?a. 1.65 m RbNO3b. 1.20 m BaCl2c. 1.50 m LiClO4d. 2.00 m C12H22O11e. 0.75 m K3PO4
Assuming complete dissociation of the soluble salts, which of the following aqueous solutions will have the lowest boiling point?1. 0.09 m Na 3PO42. 0.10 m CaF23. 0.11 m FeCl34. 0.12 m K 2CO35. 0.16 m CsCl
Membrane osmometry is a technique used to find the molecular weight of polymers by determining the osmotic pressure of a solvent across a semipermeable membrane. What is the molecular weight of the water soluble polymer, polyacrylamide, with a concentration of 100 g/L that produces an osmotic pressure of 8 × 10−3 atm at 25◦C?1. 30,900 g/mol2. 305,000 g/mol3. 2,600,000 g/mol4. 25,600 g/mol
NOTE: Glucose is a nonelectrolyte.Consider 0.01  m aqueous solutions of each of the following:a) Nal;b) CaCl2;c) K3PO4; andd) C6H12O6 glucoseArrange the solutions in order of freezing point from lowest to highest. Assume that each compound behaves ideally.1. None of these2. a, d, b, c3. c, d, a, b4. c, b, d, a5. d, a, b, c6. a, b, c, d7. d, c, b, a8. b, a, d, c
A solution that contains 12.6 g of a solid nonvolatile nonelectrolyte dissolved in 400 g of benzene freezes at 3.6°C. The normal freezing point of benzene is 5.5°C. What is the molar mass of the solute? (Kf for benzene is 4.96°C kg/mole)
Which solution has the lower freezing point? (a) 11.0 g of CH3OH in 100. g of H2O or 22.0 g of CH3CH2OH in 200. g of H2O
Which solution has the lower freezing point?(b) 20.0 g of H2O in 1.00 kg of CH3OHor 20.0 g of CH3CH2OH in 1.00 kg of CH3OH
Which solution has the higher boiling point? (a) 38.0 g of C3H8O3 in 250. g of ethanol or 38.0 g of C2H6O2 in 250. g of ethanol
Which solution has the higher boiling point?(b) 15 g of C2H6O2 in 0.50 kg of H2O or15 g of NaCl in 0.50 kg of H2O
Arrange the following solutions in order by their decreasing freezing points: 0.1 m Na3PO4, 0.1 m C2H5OH, 0.01 m CO2, 0.15 m NaCl, and 0.2 m CaCl2.
Rank the following aqueous solutions in order of increasing(b) boiling point;(I) 0.100 m NaNO3 (II) 0.100 m glucose(III) 0.100 m CaCl2
Rank the following aqueous solutions in order of increasing(c) freezing point;(I) 0.100 m NaNO3 (II) 0.100 m glucose(III) 0.100 m CaCl2
Explain the following on the basis of the behavior of atoms and/or ions: Cooking with water is faster in a pressure cooker than in an open pan.
Explain the following on the basis of the behavior of atoms and/or ions: Salt is used on icy roads.
Explain the following on the basis of the behavior of atoms and/or ions: Melted sea ice from the Arctic Ocean produces fresh water.
Rank the following aqueous solutions in order of decreasing(b) boiling point;(I) 0.04 m urea [(NH2)2C=O](II) 0.01 m AgNO3 (III) 0.03 m CuSO4
Explain the following on the basis of the behavior of atoms and/or ions: Adding a solute to a solvent extends the liquid phase over a larger temperature range.
Rank the following aqueous solutions in order of decreasing(c) freezing point;(I) 0.04 m urea [(NH2)2C=O](II) 0.01 m AgNO3 (III) 0.03 m CuSO4
The freezing point of an aqueous solution is 22.79˚C. Determine the boiling point of this solution. Explain any assumptions you make in solving the problem.
The freezing point of an aqueous solution is 22.79˚C. Determine the vapor pressure (in mm Hg) of this solution at 25˚C (the vapor pressure of pure water at 25˚C is 23.76 mm Hg). Explain any assumptions you make in solving the problem.
Which is/are part of the macroscopic domain of solutions and which is/are part of the microscopic domain: boiling point elevation, Henry’s law, hydrogen bond, ion-dipole attraction, molarity, nonelectrolyte, nonstoichiometric compound, osmosis, solvated ion?
A solution of potassium nitrate, an electrolyte, and a solution of glycerin (C3H5(OH)3), a nonelectrolyte, both boil at 100.3 °C. What other physical properties of the two solutions are identical?
Four 0.50 m aqueous solutions are depicted below. Assume that the solutions behave ideally.(a) Which has the highest boiling point?
Four 0.50 m aqueous solutions are depicted below. Assume that the solutions behave ideally.(b) Which has the lowest freezing point?
The vapor pressures of several solutions of water–propanol (CH3CH2CH2OH) were determined at various compositions, with the following data collected at 45°C:d. Which of the solutions in the data would have the lowest normal boiling point?
Consider the following solutions:0.010 m Na 3PO4 in water0.020 m CaBr 2 in water0.020 m KCl in water0.020 m HF in water (HF is a weak acid.)Which solution would have the largest freezing-point depression?
From the following:pure watersolution of C12H22O11 (m = 0.01) in watersolution of NaCl (m = 0.01) in watersolution of CaCl 2 (m = 0.01) in waterChoose the one with the highest freezing point.
From the following:pure watersolution of C12H22O11 (m = 0.01) in watersolution of NaCl (m = 0.01) in watersolution of CaCl2 (m = 0.01) in waterChoose the one with the lowest freezing point.
From the following:pure watersolution of C12H22O11 (m = 0.01) in watersolution of NaCl (m = 0.01) in watersolution of CaCl2 (m = 0.01) in waterChoose the one with the highest boiling point.
From the following:pure watersolution of C12H22O11 (m = 0.01) in watersolution of NaCl (m = 0.01) in watersolution of CaCl2 (m = 0.01) in waterChoose the one with the lowest boiling point.
Determine the van’t Hoff factor for the following ionic solute dissolved in water.
Determine the van’t Hoff factor for the following ionic solute dissolved in water.
Use the following data for three aqueous solutions of CaCl2 to calculate the apparent value of the van’t Hoff factor.
Explain the role and meaning of the van't Hoff factor in determining the colligative properties of solutions containing ionic solutes.
A 1.0 m solution of HCl in benzene has a freezing point of 0.4 °C. Is HCl an electrolyte in benzene? Explain.
In a significant experiment performed many years ago, 5.6977 g of cadmium iodide in 44.69 g of water raised the boiling point 0.181 °C. What does this suggest about the nature of a solution of CdI2?
A 1.26 m aqueous solution of an ionic compound with the formula MX2 has a boiling point of 101.55 oC. Calculate the van't Hoff factor (i) for MX2 at this concentration.
A 0.126 M ionic solution has an osmotic pressure of 8.3 atm at 28 oC. Calculate the van't Hoff factor (i) for this solution.
A solution contains 8.94 g of KBr in 500.0 mL of solution and has an osmotic pressure of 6.99 atm at 25 oC. Calculate the van't Hoff factor (i) for KBr at this concentration.
An aqueous solution contains 12.6 % NaCl by mass.What mass of water (in grams) is contained in 2.5 L of the vapor above this solution at 55 oC? The vapor pressure of pure water at 55 oC is 118 torr. (Assume a van't Hoff factor of 1.9 for NaCl.)
A solution is prepared from 4.5726 g of magnesium chloride and 43.242 g of water. The vapor pressure of water above this solution is found to be 0.3626 atm at 348.0 K. The vapor pressure of pure water at this temperature is 0.3804 atm.Find the value of the van't Hoff factor (i) for magnesium chloride in this solution.
A sample of HgCl2 weighing 9.41 g is dissolved in 32.75 g of ethanol, C2H5OH (Kb = 1.20 °C/m). The boiling point elevation of the solution is 1.27 °C. Is HgCl2 an electrolyte in ethanol? Show your calculations.
You may want to reference (Pages 605 - 606) Section 13.7 while completing this problem.A 2.4 m aqueous solution of an ionic compound with the formula MX2 has a boiling point of 103.4 oC. Calculate the van't Hoff factor (i) for MX2 at this concentration.
A solution of 1.50 g of solute dissolved in 25.0 mL of H2O at 25°C has a boiling point of 100.45°C.(d) Find the van’t Hoff factor (i) for this solution.
Why does 1 mol of sodium chloride depress the freezing point of 1 kg of water almost twice as much as 1 mol of glycerin?
You may want to reference (Pages 608 - 608)section 13.7 while completing this problem.A 0.93 m aqueous solution of an ionic compound with the formula MX has a freezing point of -2.7 ˚C. Calculate the van't Hoff factor (i) for MX at this concentration.
What is Raoult's law? For what kind of calculations is Raoult's law useful?
A solution contains 5.00 g of urea, CO(NH2)2, a nonvolatile compound, dissolved in 0.100 kg of water. If the vapor pressure of pure water at 25 °C is 23.7 torr, what is the vapor pressure of the solution?
Rank the following aqueous solutions in order of increasing(d) vapor pressure at 50°C:(I) 0.100 m NaNO3 (II) 0.100 m glucose(III) 0.100 m CaCl2
Rank the following aqueous solutions in order of decreasing(d) vapor pressure at 298 K:(I) 0.04 m urea [(NH2)2C=O](II) 0.01 m AgNO3 (III) 0.03 m CuSO4
At 25˚C, the vapor in equilibrium with a solution containing carbon disulfide and acetonitrile has a total pressure of 263 torr and is 85.5 mole percent carbon disulfide. What is the mole fraction of carbon disulfide in the solution? At 25˚C, the vapor pressure of carbon disulfide is 375 torr. Assume the solution and vapor exhibit ideal behavior.
Calculate the vapor pressure of a solution of 34.0 g of glycerol (C3H8O3) in 500.0 g of water at 25°C. The vapor pressure of water at 25°C is 23.76 torr. (Assume ideal behavior.)
Calculate the vapor pressure of a solution of 0.39 mol of cholesterol in 5.4 mol of toluene at 32°C. Pure toluene has a vapor pressure of 41 torr at 32°C. (Assume ideal behavior.)
A solution is made by mixing 50.0 g acetone (CH 3COCH3) and 50.0 g methanol (CH3OH). What is the vapor pressure of this solution at 25˚C? What is the composition of the vapor expressed as a mole fraction? Assume ideal solution and gas behavior. (At 25˚C the vapor pressures of pure acetone and pure methanol are 271 and 143 torr, respectively.) The actual vapor pressure of this solution is 161 torr. Explain any discrepancies.
Calculate the vapor pressure of a solution containing 26.6 g of glycerin (C3H8O3) in 128 mL of water at 30.0 oC. The vapor pressure of pure water at this temperature is 31.8 torr. Assume that glycerin is not volatile and dissolves molecularly (i.e., it is not ionic) and use a density of 1.00 g/mL for the water.
You may want to reference (Pages 593 - 607) Section 13.6 while completing this problem.A solution contains naphthalene (C10H8) dissolved in hexane (C6H14) at a concentration of 12.51 % naphthalene by mass. Calculate the vapor pressure at 25 oC of hexane above the solution. The vapor pressure of pure hexane at 25 oC is 151 torr.
A solution contains 50.5 g of heptane (C7H16) and 50.5 g of octane (C8H18) at 25 oC. The vapor pressures of pure heptane and pure octane at 25 oC are 45.8 torr and 10.9 torr, respectively. Assuming ideal behavior, calculate each of the following. (Note that the mole fraction of an individual gas component in an ideal gas mixture can be expressed in terms of the components partial pressure.)The vapor pressure of heptane in the mixture.
A solution contains 50.5 g of heptane (C7H16) and 50.5 g of octane (C8H18) at 25 oC. The vapor pressures of pure heptane and pure octane at 25 oC are 45.8 torr and 10.9 torr, respectively. Assuming ideal behavior, calculate each of the following. (Note that the mole fraction of an individual gas component in an ideal gas mixture can be expressed in terms of the components partial pressure.)The total pressure above the solution.
A solution contains 50.5 g of heptane (C7H16) and 50.5 g of octane (C8H18) at 25 oC. The vapor pressures of pure heptane and pure octane at 25 oC are 45.8 torr and 10.9 torr, respectively. What is the mass percent concentration of heptane in vapour phase?
A solution contains 50.5 g of heptane (C7H16) and 50.5 g of octane (C8H18) at 25 oC. The vapor pressures of pure heptane and pure octane at 25 oC are 45.8 torr and 10.9 torr, respectively. Why is the composition of the vapor different from the composition of the solution?
Two liquids, A and B, have vapor pressures at a given temperature of 24 mmHg and 36 mmHg, respectively. We prepare solutions of A and B at a given temperature and measure the total pressures above the solutions. We obtain the following data:SolutionAmt A (mol)Amt B (mol)P (mmHg)11130221283123241333Predict the total pressure above a solution of 1 molA and 5 molB.
A solution contains 50.5 g of heptane (C7H16) and 50.5 g of octane (C8H18) at 25 oC. The vapor pressures of pure heptane and pure octane at 25 oC are 45.8 torr and 10.9 torr, respectively. Assuming ideal behavior, calculate each of the following. (Note that the mole fraction of an individual gas component in an ideal gas mixture can be expressed in terms of the components partial pressure.)The vapor pressure of octane in the mixture.
A solution contains 50.5 g of heptane (C7H16) and 50.5 g of octane (C8H18) at 25 oC. The vapor pressures of pure heptane and pure octane at 25 oC are 45.8 torr and 10.9 torr, respectively. What is the mass percent concentration of octane in vapour phase?
Volatile organic solvents have been implicated in adverse health effects observed in industrial workers. Greener methods are phasing these solvents out. Rank the solvents in Table 13.6 in terms of increasing volatility.
Sketch a qualitative graph of the pressure versus time for water vapor above a sample of pure water and a sugar solution, as the liquids evaporate to half their original volume.
Glycerin, C3H8O3, is a nonvolatile liquid. What is the vapor pressure of a solution made by adding 164 g glycerin to 338 mL H2O at 39.8°C? The vapor pressure of pure water at 39.8°C is 54.74 torr and its density is 0.992 g/cm3.
The vapor pressure of a solution containing 53.6 g glycerin (C3H8O3) in 133.7 g ethanol (C2H5OH) is 113 torr at 40°C. Calculate the vapor pressure of pure ethanol at 40°C assuming that glycerin is a nonvolatile, nonelectrolyte solute in ethanol.
The U.S. Food and Drug Administration lists dichloromethane (CH2Cl2) and carbon tetrachloride (CCl4) among the many cancer-causing chlorinated organic compounds. What are the partial pressures of these substances in the vapor above a solution of 1.60 mol of CH2Cl2 and 1.10 mol of CCl4 at 23.5°C? The vapor pressures of pure CH2Cl2 and CCl4 at 23.5°C are 352 torr and 118 torr, respectively. (Assume ideal behavior.)
A solution is made by dissolving 25.8 g urea (CH4N2O), a nonelectrolyte, in 275 g water. Calculate the vapor pressures of this solution at 25°C and 45°C. (The vapor pressure of pure water is 23.8 torr at 25°C and 71.9 torr at 45°C.)
A solution of sodium chloride in water has a vapor pressure of 19.6 torr at 25°C. What is the mole fraction of solute particles in this solution? What would be the vapor pressure of this solution at 45°C? The vapor pressure of pure water is 23.8 torr at 25°C and 71.9 torr at 45°C, and assume sodium chloride exists as Na+ and Cl- ions in solution.
Pentane (C5H12) and hexane (C6H14) form an ideal solution. At 25°C the vapor pressures of pentane and hexane are 511 and 150. torr, respectively. A solution is prepared by mixing 25 mL pentane (density, 0.63 g/mL) with 45 mL hexane(density, 0.66 g/mL).a. What is the vapor pressure of the resulting solution?
Pentane (C5H12) and hexane (C6H14) form an ideal solution. At 25°C the vapor pressures of pentane and hexane are 511 and 150. torr, respectively. A solution is prepared by mixing 25 mL pentane (density, 0.63 g/mL) with 45 mL hexane(density, 0.66 g/mL).b. What is the composition by mole fraction of pentane in the vapor that is in equilibrium with this solution?
A solution is prepared by mixing 0.0300 mole of CH2Cl2 and 0.0500 mole of CH2Br2 at 25°C. Assuming the solution is ideal, calculate the composition of the vapor (in terms of mole fractions) at 25°C. At 25°C, the vapor pressures of pure CH2Cl2 and pure CH2Br2 are 133 and 11.4 torr, respectively.
What is the composition of a methanol (CH3OH)–propanol (CH3CH2CH2OH) solution that has a vapor pressure of 174 torr at 40°C? At 40°C, the vapor pressures of pure methanol and pure propanol are 303 and 44.6 torr, respectively. Assume the solution is ideal.
The vapor pressure of methanol, CH3OH, is 94 torr at 20 °C. The vapor pressure of ethanol, C2H5OH, is 44 torr at the same temperature.(a) Calculate the mole fraction of methanol and of ethanol in a solution of 50.0 g of methanol and 50.0 g of ethanol.
Distillation is a method of purification based on successive separations and recondensations of vapor above a solution.The vapor pressure of carbon tetrachloride, CCl4, is 0.354 atm and the vapor pressure of chloroform, CHCl3, is 0.526 atm at 316 K. A solution is prepared from equal masses of these two compounds at this temperature. The mole fraction of chloroform in the vapor above this solution is χCHCl3 = 0.657. If the vapor above the original solution is condensed and isolated into a separate flask, the vapor pressure of chloroform above this new solution is 0.346 atm.Calculate the mole fraction of chloroform in the vapor above a solution obtained by three successive separations and condensations of the vapors above the original solution of carbon tetrachloride and chloroform.
Benzene and toluene form an ideal solution. Consider a solution of benzene and toluene prepared at 25°C. Assuming the mole fractions of benzene and toluene in the vapor phase are equal, calculate the composition of the solution. At 25°C the vapor pressures of benzene and toluene are 95 and 28 torr, respectively.
Gaseous O2 in equilibrium with O2 dissolved in water at 283 K is depicted at right.(a) Which scene below represents the system at 298 K?
Gaseous O2 in equilibrium with O2 dissolved in water at 283 K is depicted at right.(b) Which scene represents the system when the pressure of O2 is increased by half?
Which of the following will have the lowest total vapor pressure at 25°C?a. pure water (vapor pressure = 23.8 torr at 25°C)b. a solution of glucose in water with   = 0.01c. a solution of sodium chloride in water with   = 0.01d. a solution of methanol in water with   = 0.2 (Consider the vapor pressure of both methanol [143 torr at 25°C] and water.)
The vapor pressure of methanol, CH3OH, is 94 torr at 20 °C. The vapor pressure of ethanol, C2H5OH, is 44 torrat the same temperature.(b) Ethanol and methanol form a solution that behaves like an ideal solution. Calculate the vapor pressure of methanol and of ethanol above the solution at 20 °C.
A solution is prepared by mixing 1.000 mole of methanol (CH 3OH) and 3.18 moles of propanol (CH3CH2CH2OH). What is the composition of the vapor (in mole fractions) at 40˚C? At 40˚C, the vapor pressure of pure methanol is 303 torr, and the vapor pressure of pure propanol is 44.6 torr.
Two alcohols, isopropyl alcohol and propyl alcohol, have the same molecular formula, C3H8O. A solution of the two that is two-thirds by mass isopropyl alcohol has a vapor pressure of 0.110 atm at 313 K. A solution that is one-third by mass isopropyl alcohol has a vapor pressure of 0.089 atm at 313 K.Calculate the vapor pressure of each pure alcohol at this temperature.
Match the vapor pressure diagrams with the solute–solvent combinations and explain your answers.a. 
Match the vapor pressure diagrams with the solute–solvent combinations and explain your answers.b. 
Match the vapor pressure diagrams with the solute–solvent combinations and explain your answers.c. 
Match the vapor pressure diagrams with the solute–solvent combinations and explain your answers.d. 
The vapor pressures of several solutions of water–propanol (CH3CH2CH2OH) were determined at various compositions, with the following data collected at 45°C:a. Are solutions of water and propanol ideal? Explain.
The vapor pressures of several solutions of water–propanol (CH3CH2CH2OH) were determined at various compositions, with the following data collected at 45°C:b. Predict the sign of ΔHsoln for water–propanol solutions.
The vapor pressures of several solutions of water–propanol (CH3CH2CH2OH) were determined at various compositions, with the following data collected at 45°C:c. Are the interactive forces between propanol and water molecules weaker than, stronger than, or equal to the interactive forces between the pure substances? Explain.
The vapor pressure of methanol, CH3OH, is 94 torr at 20 °C. The vapor pressure of ethanol, C2H5OH, is 44 torr at the same temperature.(c) Calculate the mole fraction of methanol and of ethanol in the vapor above the solution.
You may want to reference (Pages 597 - 599) Section 13.6 while completing this problem.A solution contains a mixture of substance A and substance B, both of which are volatile. The mole fraction of substance A is 0.35. At 32 oC the vapor pressure of pure A is 87 mmHg and the vapor pressure of pure B is 122 mmHg. What is the total vapor pressure of the solution at this temperature?
β-Pinene (C10H16) and α-terpineol (C10H18O) are used in cosmetics to provide a “fresh pine” scent. At 367 K, the pure substances have vapor pressures of 100.3 torr and 9.8 torr, respectively. What is the composition of the vapor (in terms of mole fractions) above a solution containing equal masses of these compounds at 367 K? (Assume ideal behavior.)
A pharmaceutical preparation made with ethanol (C2H5OH) is contaminated with methanol (CH3OH). A sample of vapor above the liquid mixture contains a 97/1 mass ratio of C2H5OH to CH3OH. What is the mass ratio of these alcohols in the liquid mixture? At the temperature of the liquid mixture, the vapor pressures of C2H5OH and CH3OH are 60.5 torr and 126.0 torr, respectively.
You may want to reference (Pages 593 - 607)section 13.6 while completing this problem.A solution contains a mixture of pentane and hexane at room temperature. The solution has a vapor pressure of 256 torr. Pure pentane and hexane have vapor pressures of 425 torr and 151 torr, respectively, at room temperature. What is the mole fraction of hexane? (Assume ideal behavior.)
Consider the following solutions:0.010 m Na 3PO4 in water0.020 m CaBr 2 in water0.020 m KCl in water0.020 m HF in water (HF is a weak acid.)Which solution would have the highest vapor pressure at 28˚C?
What is the molar mass of a solution of 5.00 g of a compound in 25.00 g of carbon tetrachloride (bp = 76.8 °C; Kb = 5.02 °C/m) that boils at 81.5 °C at 1 atm?(a) Outline the steps necessary to answer the question.(b) Solve the problem.
A 0.500-g sample of a compound is dissolved in enough water to form 100.0 mL of solution. This solution has an osmotic pressure of 2.50 atm at 25˚C. If each molecule of the solute dissociates into two particles (in this solvent), what is the molar mass of this solute?
A sample of an organic compound (a nonelectrolyte) weighing 1.35 g lowered the freezing point of 10.0 g of benzene by 3.66 °C. Calculate the molar mass of the compound.
A 12.0-g sample of a nonelectrolyte is dissolved in 80.0 g of water. The solution freezes at −1.94 °C. Calculate the molar mass of the substance.
A solution of 5.0 g of benzoic acid (C6H5COOH) in 100.0 g of carbon tetrachloride has a boiling point of 77.5°C. (a) Calculate the molar mass of benzoic acid in the solution.
A solution of 5.0 g of benzoic acid (C6H5COOH) in 100.0 g of carbon tetrachloride has a boiling point of 77.5°C.(b) Suggest a reason for the difference between the molar mass based on the formula and that found in part (a). (Hint: Consider intermolecular forces in this compound.)
Urea is a white crystalline solid used as a fertilizer, in the pharmaceutical industry, and in the manufacture of certain polymer resins. Analysis of urea reveals that, by mass, it is 20.1% carbon, 6.7% hydrogen, 46.5% nitrogen, and the balance oxygen.(b) A 5.0 g/L solution of urea in water has an osmotic pressure of 2.04 atm, measured at 25°C. What are the molar mass and molecular formula of urea?
A solution made by dissolving 31.7 g of an unknown compound in 150. g of water freezes at −1.15°C. What is the molar mass of the compound?
A 125-mL sample of an aqueous solution of the protein ovalbumin from chicken egg white contains 1.31 g of the dissolved protein and has an osmotic pressure of 4.32 torr at 25°C. What is the molar mass of ovalbumin?
Thyroxine, an important hormone that controls the rate of metabolism in the body, can be isolated from the thyroid gland. When 0.455 g thyroxine is dissolved in 10.0 g benzene, the freezing point of the solution is depressed by 0.300˚C. What is the molar mass of thyroxine? See Table 10‑5.
A sample of sulfur weighing 0.210 g was dissolved in 17.8 g of carbon disulfide, CS2 (Kb = 2.43 °C/m). If the boiling point elevation was 0.107 °C, what is the formula of a sulfur molecule in carbon disulfide?
An unknown compound contains only carbon, hydrogen, and oxygen. Combustion analysis of the compound gives mass percents of 31.57% C and 5.30% H. The molar mass is determined by measuring the freezing-point depression of an aqueous solution. A freezing point of 25.20˚C is recorded for a solution made by dissolving 10.56 g of the compound in 25.0 g water. Determine the empirical formula, molar mass, and molecular formula of the compound. Assume that the compound is a nonelectrolyte.
An aqueous solution containing 17.1 g of an unknown molecular (nonelectrolyte) compound in 105.5 g of water was found to have a freezing point of -1.7 oC. Calculate the molar mass of the unknown compound.
A solution containing 27.55 mg of an unknown protein per 25.5 mL solution was found to have an osmotic pressure of 3.55 torr at 28 oC. What is the molar mass of the protein?
In a study designed to prepare new gasoline-resistant coatings, a polymer chemist dissolves 6.053 g of poly(vinyl alcohol) in enough water to make 100.0 mL of solution. At 25°C, the osmotic pressure of this solution is 0.272 atm. What is the molar mass of the polymer sample?
At a certain temperature, the vapor pressure of pure benzene (C6H6) is 0.930 atm. A solution was prepared by dissolving 10.0 g of a nondissociating, nonvolatile solute in 78.11 g of benzene at that temperature. The vapor pressure of the solution was found to be 0.900 atm. Assuming the solution behaves ideally, determine the molar mass of the solute.
Patients undergoing an upper gastrointestinal tract laboratory test are typically given an X-ray contrast agent that aids with the radiologic imaging of the anatomy. One such contrast agent is sodium diatrizoate, a nonvolatile water-soluble compound. A 0.378-m solution is prepared by dissolving 38.4 g sodium diatrizoate (NaDTZ) in 1.60 x 102 mL water at 31.2˚C (the density of water at 31.2˚C is 0.995 g/cm3). What is the molar mass of sodium diatrizoate? What is the vapor pressure of this solution if the vapor pressure of pure water at 31.2˚C is 34.1 torr?
The sugar fructose contains 40.0% C, 6.7% H, and 53.3% O by mass. A solution of 11.7 g of fructose in 325 g of ethanol has a boiling point of 78.59 °C. The boiling point of ethanol is 78.35 °C, and Kb for ethanol is 1.20 °C/m. What is the molecular formula of fructose?
A chemist is studying small organic compounds to evaluate their potential for use as an antifreeze. When 0.243 g of a compound is dissolved in 25.0 mL of water, the freezing point of the solution is −0.201°C. (a) Calculate the molar mass of the compound (d of water = 1.00 g/mL).
A chemist is studying small organic compounds to evaluate their potential for use as an antifreeze. When 0.243 g of a compound is dissolved in 25.0 mL of water, the freezing point of the solution is −0.201°C.(b) Analysis shows that the compound is 53.31 mass % C and 11.18 mass % H, the remainder being O. Determine the empirical and molecular formulas of the compound.
A 2.00-g sample of a large biomolecule was dissolved in 15.0 g carbon tetrachloride. The boiling point of this solutionwas determined to be 77.85°C. Calculate the molar mass of the biomolecule. For carbon tetrachloride, the boiling-point constant is 5.03°C ? kg/mol, and the boiling point of pure carbon tetrachloride is 76.50°C.
A solution contains 3.75 g of a nonvolatile pure hydrocarbon in 95 g acetone. The boiling points of pure acetone and the solution are 55.95°C and 56.50°C, respectively. The molal boilingpoint constant of acetone is 1.71°8C • kg/mol. What is the molar mass of the hydrocarbon?
You may want to reference (Pages 603 - 605) Section 13.6 while completing this problem.The osmotic pressure of a solution containing 22.7 mg of an unknown protein in 50.0 mL of solution is 2.88 mmHg at 25 oC. Determine the molar mass of the protein.
An organic compound has a composition of 93.46% C and 6.54% H by mass. A solution of 0.090 g of this compound in 1.10 g of camphor melts at 158.4 °C. The melting point of pure camphor is 178.4 °C. Kf for camphor is 37.7 °C/m. What is the molecular formula of the solute? Show your calculations.
A salt is known to be an alkali metal fluoride. A quick approximate determination of freezing point indicates that 4 g of the salt dissolved in 100 g of water produces a solution that freezes at about −1.4 °C. What is the formula of the salt? Show your calculations.
A solution of 1.50 g of solute dissolved in 25.0 mL of H2O at 25°C has a boiling point of 100.45°C. (a) What is the molar mass of the solute if it is a nonvolatile nonelectrolyte and the solution behaves ideally (d of H2O at 25°C = 0.997 g/mL)?
A solution of 1.50 g of solute dissolved in 25.0 mL of H2O at 25°C has a boiling point of 100.45°C.(b) Conductivity measurements show that the solute is ionic with general formula AB2 or A2B. What is the molar mass if the solution behaves ideally?
A solution of 1.50 g of solute dissolved in 25.0 mL of H2O at 25°C has a boiling point of 100.45°C.(c) Analysis indicates that the solute has an empirical formula of CaN2O6. Explain the difference between the actual formula mass and that calculated from the boiling point elevation.
A biochemical engineer isolates a bacterial gene fragment and dissolves a 10.0-mg sample in enough water to make 30.0 mL of solution. The osmotic pressure of the solution is 0.340 torr at 25°C. (a) What is the molar mass of the gene fragment?
An aqueous solution of 10.00 g of catalase, an enzyme found in the liver, has a volume of 1.00 L at 27˚C. The solution’s osmotic pressure at 27˚C is found to be 0.745 torr. Calculate the molar mass of catalase.
A 0.15-g sample of a purified protein is dissolved in water to give 2.0 mL of solution. The osmotic pressure is found to be 18.6 torr at 25˚C. Calculate the protein’s molar mass.
You may want to reference (Pages 593 - 607)section 13.6 while completing this problem.An aqueous solution containing 35.6 g  of an unknown molecular (non-electrolyte) compound in 150.1 g of water was found to have a freezing point of -1.3 oC.Calculate the molar mass of the unknown compound.
A water desalination plant is set up near a salt marsh containing water that is 0.10 M NaCl. Calculate the minimum pressure that must be applied at 20.˚C to purify the water by reverse osmosis. Assume NaCl is completely dissociated.
What is the osmotic pressure of an aqueous solution of 1.64 g of Ca(NO3)2 in water at 25 °C? The volume of the solution is 275 mL.(a) Outline the steps necessary to answer the question.(b) Answer the question
What is osmotic pressure of a solution of bovine insulin (molar mass, 5700 g mol−1) at 18 °C if 100.0 mL of the solution contains 0.103 g of the insulin?(a) Outline the steps necessary to answer the question.(b) Answer the question.
Rank the following aqueous solutions in order of increasing (a) osmotic pressure; (I) 0.100 m NaNO3 (II) 0.100 m glucose (III) 0.100 m CaCl2
Rank the following aqueous solutions in order of decreasing (a) osmotic pressure; (I) 0.04 m urea [(NH2)2C=O] (II) 0.01 m AgNO3 (III) 0.03 m CuSO4
A small protein has a molar mass of 1.50×104 g/mol. What is the osmotic pressure exerted at 24.0°C by 25.0 mL of an aqueous solution that contains 37.5 mg of the protein?
At 37°C, 0.30 M sucrose has about the same osmotic pressure as blood. What is the osmotic pressure of blood?
If the human eye has an osmotic pressure of 8.00 atm at 25˚C, what concentration of solute particles in water will provide an isotonic eyedrop solution (a solution with equal osmotic pressure)?
Consider the following:What would happen to the level of liquid in the two arms if the semipermeable membrane separating the two liquids were permeable to H2O (the solvent) only?
Consider the following:What would happen to the level of liquid in the two arms if the semipermeable membrane separating the two liquids were permeable to H2O and solute?
Lysozyme is an enzyme that cleaves cell walls. A 0.100-L sample of a solution of lysozyme that contains 0.0750 g of the enzyme exhibits an osmotic pressure of 1.32 × 10−3 atm at 25 °C. What is the molar mass of lysozyme?
Calculate the osmotic pressure of a solution containing 23.6 g of glycerin (C3H8O3) in 250.5 mL of solution at 305 K .
The osmotic pressure of a solution containing 7.0 g of insulin per liter is 23 torr at 25 °C. What is the molar mass of insulin?
Which of the following solutions will have the highest concentration of chloride ions? a. 0.10 M NaCl b. 0.10 M AlCl3 c. 0.10 M MgCl2 d. 0.05 M CaCl2 e. All of these solutions have the same concentration of chloride ions
Specifications for lactated Ringer’s solution, which is used for intravenous (IV) injections, are as follows to reach 100. mL of solution:• 285–315 mg Na+                          • 368–408 mg Cl   –• 14.1–17.3 mg K+                          • 231–261 mg lactate, C   3H5O3–• 4.9–6.0 mg Ca 2+What is the range of the osmotic pressure of the solution at 37˚C, given the preceding specifications?
The osmotic pressure of human blood is 7.6 atm at 37 °C. What mass of glucose, C6H12O6, is required to make 1.00 L of aqueous solution for intravenous feeding if the solution must have the same osmotic pressure as blood at body temperature, 37 °C?
An isotonic solution contains 0.91 % NaCl by mass per volume. Calculate the percent mass per volume for isotonic solutions containing each of the following solutes at 35 oC. Assume a van't Hoff factor of 1.9 for all ionic solutes.KCl
An isotonic solution contains 0.91 % NaCl by mass per volume. Calculate the percent mass per volume for isotonic solutions containing each of the following solutes at 35 oC. Assume a van't Hoff factor of 1.9 for all ionic solutes.NaBr
An isotonic solution contains 0.91 % NaCl by mass per volume. Calculate the percent mass per volume for isotonic solutions containing each of the following solutes at 35 oC. Assume a van't Hoff factor of 1.9 for all ionic solutes.Glucose (C6 H12 O6)
Magnesium citrate, Mg3(C6H5O7 )2, belongs to a class of laxatives called hyperosmotics, which are used for rapid emptying of the bowel. When a concentrated solution of magnesium citrate is consumed, it passes through the intestines, drawing water and promoting diarrhea, usually within 6 hours.Calculate the osmotic pressure of a magnesium citrate laxative solution containing 28.0 g of magnesium citrate in 236 mL of solution at 37 oC (approximate body temperature). Assume complete dissociation of the ionic compound.
The three aqueous ionic solutions represented below have total volumes of 25. mL for A, 50. mL for B, and 100. mL for C. If each sphere represents 0.010 mol of ions, calculate:(d) the highest osmotic pressure (assuming ideal behavior).
A 1.10-g sample contains only glucose (C6H12O6) and sucrose (C12H22O11 ). When the sample is dissolved in water to a total solution volume of 25.0 mL, the osmotic pressure of the solution is 3.78 atm at 298 K. What is the percent by mass of glucose in the sample?
A 4.7 x 10 –2 mg sample of a protein is dissolved in water to make 0.25 mL of solution. The osmotic pressure of the solution is 0.56 torr at 25˚C. What is the molar mass of the protein?
A 1.10-g sample contains only glucose (C6H12O6) and sucrose (C12H22O11 ). When the sample is dissolved in water to a total solution volume of 25.0 mL, the osmotic pressure of the solution is 3.78 atm at 298 K. What is the percent by mass of sucrose in the sample?
Four 0.50 m aqueous solutions are depicted below. Assume that the solutions behave ideally.(c) Can you determine which one has the highest osmotic pressure? Explain.
Methanol, CH3OH, is a non-electrolyte; oxalic acid, H2C2O4, is a weak electrolyte; and sodium chloride, NaCl, is a strong electrolyte. Give the moles of solute particles formed by each if 0.1 mol of each compound is dissolved in water. Write equations to show your reasoning.0.1 mol of particles:Compound-equation-0.2 mol of particles:Compound-equation-between 0.1 and 0.2 mol particles:Compound-equation-
Erythrocytes are red blood cells containing hemoglobin. In a saline solution they shrivel when the salt concentration is high and swell when the salt concentration is low. In a 25°C aqueous solution of NaCl, whose freezing point is -0.406°C, erythrocytes neither swell nor shrink. If we want to calculate the osmotic pressure of the solution inside the erythrocytes under these conditions, what do we need to assume? Why? Estimate how good (or poor) of an assumption this is. Make this assumption and calculate the osmotic pressure of the solution inside the erythrocytes.
Four U tubes each have distilled water in the right arm, a solution in the left arm, and a semipermeable membrane between the arms.(a) If the solute is KCl, which solution is most concentrated?
Four U tubes each have distilled water in the right arm, a solution in the left arm, and a semipermeable membrane between the arms.(b) If each solute is different but all the solutions have the same molarity, which contains the smallest number of dissolved ions?
Use the van't Hoff factors in the table below to calculate each colligative property:Van't Hoff Factors at 0.05 m Concentration in Aqueous SolutionSolute/Expected/MeasuredNonelectrolyte11NaCl21.9MgSO421.3MgCl232.7K2SO432.6FeCl343.4Calculate the osmotic pressure of a 9.3×10−2 M potassium sulfate solution at 306K.
You may want to reference (Pages 609 - 610)  Section 13.7 while completing this problem.Using the van't Hoff factors in the table below, calculate the mass of solute required to make each aqueous solution.Van't Hoff factors at 0.05 m concentration in aqueous solutionSoluteExpectedMeasuredNonelectrolyte11NaCl21.9MgSO421.3MgCl232.7K2SO432.6FeCl343.4Calculate the mass of solute required to make 261 mL of a magnesium sulfate solution that has an osmotic pressure of 3.91 atm at 307 K .
How would you prepare 1.0 L of an aqueous solution of sucrose (C 12H22O11) having an osmotic pressure of 15 atm at a temperature of 22˚C? Sucrose is a nonelectrolyte.
How would you prepare 1.0 L of an aqueous solution of sodium chloride having an osmotic pressure of 15 atm at 22˚C? Assume sodium chloride exists as Na+ and Cl – ions in solution.
You may want to reference (Pages 593 - 607)section 13.6 while completing this problem.Calculate the osmotic pressure of a solution containing 18.30 mg of hemoglobin in 15.1  mL of solution at 26 oC. The molar mass of hemoglobin is 6.5 x 104 g/mol.
From the following:pure watersolution of C12H22O11 (m = 0.01) in watersolution of NaCl (m = 0.01) in watersolution of CaCl2 (m = 0.01) in waterChoose the one with the highest osmotic pressure.
Question 9 (10 points) Why is the concentration in the freezing point depression molality instead of molarity? (i) Poor molality isn't used much, so why not here. (ii) Molarity changes with temperature, so is not a good unit for this type of experiment. (iii) The lowercase m looks better in this equation. (iv) when the van't Hoff factor is used molality must be the concentration unit.
Calculate the osmotic pressure of a 5.0 x 10^-2 M solution of NaCl at 25 C (298 K).
When 0.884 grams of a protein were dissolved in 72.1 mL of solution at 25.8°C, the osmotic pressure was found to be 0.025 atm. Calculate the molar mass of the protein.
A solution prepared by dissolving 1.703 g of sucrose, a nonelectrolyte, in enough water to produce 220.0 mL of solution has an osmotic pressure of 420.3 mm Hg at 298 K. What is the molecular weight of sucrose? Express your answer to four significant figures and include the appropriate units.
Calculate the osmolarity of a 1.20 M solution of (NH 4)2S. 
What is the osmotic pressure developed at 41°C by an aqueous solution that is 0.227 M in AICI3?
Calculate the osmotic pressure of a solution containing 19.45 mg of hemoglobin in 15.9 mL of solution at 28°C. The molar mass of hemoglobin is 6.5 x 104 g/mol. Express your answer in atmospheres. 
A water solution that contains 16.1 mg of an unknown enzyme in 5.00 mL of solution has an osmotic pressure of 5.69 torr at 26°C. What is the molar mass of the unknown enzyme? Do not use scientific notation to enter your answer.
Calculate the osmotic pressure across a semipermeable membrane separating pure water from seawater at 25°C. The total concentration of all the ions in seawater is 1.177 M.
When 3.55 g of a nonelectrolyte solute is dissolved in water to make 195 mL of solution at 29 °C, the solution exerts an osmotic pressure of 821 torr. What is the molar concentration of the solution? How many moles of solute are in the solution? What is the molar mass of the solute?
When 4.25 g of a nonelectrolyte solute is dissolved in water to make 255 mL of solution at 28°C, the solution exerts an osmotic pressure of 875 torr. What is the molar concentration of the solution? How many moles of solute are in the solution?What is the molar mass of the solute?
When 4.99 g of a nonelectrolyte solute is dissolved in water to make 185 mL of solution at 24°C, the solution exerts an osmotic pressure of 901 torr. What is the molar concentration of the solution? How many moles of solute are in the solution? What is the molar mass of the solute?
When 2.31 g of a nonelectrolyte solute is dissolved in water to make 905 mL of solution at 26°C, the solution exerts an osmotic pressure of 807 torr. What is the molar concentration of the solution? How many moles of solute are in the solution?
What is the total molar concentration of ions in each of the following solutions, assuming complete dissociation? A 0.685 M solution of K2CO3 
What is the osmotic pressure of 0.0100 M sodium chloride at 25°C? Assume that sodium chloride dissociates completely. a) 1.22 atm b) 0.489 atm c) 0.244 atm d) 0.976 atm e) 0.734 atm
When 2.38 g of a nonelectrolyte solute is dissolved in water to make 665 mL of solution at 23°C, the solution exerts an osmotic pressure of 959 torr.What is the molar concentration of the solution? How many moles of solute are in the solution? What is the molar mass of the solute? 
Calculate the osmotic pressure of each of the following aqueous solutions at 27°C: 
Osmotic pressure is directly proportional to the _____ of the solution.a. soluteb. solventc. molalityd. molarity 
Question 8 (10 points) When dissolving the same amount of solute into the following solvents which freezing point would be depressed the most? (i) Water, Kf = 1.86 (ii) Ethanol, Kf =  1.99 (iii) Diethyl ether, Kf = 1.79 (iv) Chloroform, Kf = 4.70 
Calculate the osmotic pressure of a solution containing 21.7 g of glycerin (C3H8O3) in 248 0 ml, of solution at 295 K.