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What is the boiling point of a solution made by dissolving 25.0 g of powdered sulfur (S8, 256.52 g/mol) in 250.0 g of carbon disulfide (CS2, 76.13 g/mol, Kb = 2.37 °\degree C/m, Tb = 46.2 °\degree C)?

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Tf,solution

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The Henry's law constant for oxygen dissolving in blood is 3.74 * 10-2 mol/L . atm at body temperature, 37 °\degree C.Calculate the molar concentration of oxygen in blood for a scuba diver where the air pressure is 2.0 atm.The mole fraction of oxygen in air is 0.209.


A) 7.8 * 10-3 M
B) 2.7 *10-3 M
C) 1.6 * 10-2 M
D) 1.3* 10-2 M
E) 0.11 M

F) C) and D)
G) A) and B)

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Which of the following regarding colligative properties of a solution is NOT correct?


A) Colligative properties depend on the concentration of the particles dissolved in the solvent.
B) Vapor pressure reduction is a colligative property.
C) The temperature range over which a solution remains liquid is larger than that of the pure solvent due to the presence of solute particles.
D) The change in the boiling point of a solvent due to the presence of a solute is a colligative property.
E) The freezing point of a solution increases as the concentration of solute increases.

F) A) and C)
G) B) and E)

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Two solutions, A and B, are separated by a semipermeable membrane.Which of the following statements regarding their tonicities is NOT correct? Assume the same van 't Hoff factor for each solution.


A) If A and B are of equal molarities, they are isotonic.
B) If the molarity of A is lower than that of B, solvent will flow from B to A.
C) If the molarity of B is lower than that of A, B is hypotonic relative to A.
D) If the molarity of A is lower than that of B, the osmotic pressure of B is higher than that of A.
E) If the molarity of B is lower than that of A, A is hypertonic relative to B.

F) C) and D)
G) All of the above

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What is the osmotic pressure of a 5.20% mass/volume aqueous ethanol (CH3CH2OH, 46.07 g/mol) solution at 25.0 °\degree C? Assume the density of the solution is 1.00 g/mL.


A) 2.32 atm
B) 27.6 atm
C) 2.80 * 103 atm
D) 58.6 atm
E) 4.91 atm

F) A) and D)
G) B) and E)

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The concentration unit of molality is symbolized as


A) M
B) m
C) M.
D) mol
E) Mo

F) All of the above
G) C) and D)

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The Henry's law constant for oxygen dissolving in blood is 3.74 *10-2 mol/L . atm at body temperature, 37 °\degree C.Calculate the molar concentration of oxygen in blood for an alpine climber where the atmospheric pressure is 0.45 atm.The mole fraction of oxygen in air is 0.209.


A) 7.8 *10-3 M
B) 3.5 * 10-3 M
C) 2.3 * 10-2 M
D) 1.3 * 10-2 M
E) 0.11 M

F) B) and D)
G) C) and E)

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Myristicin is a hallucinogenic compound found naturally in nutmeg.A 425 mg sample of myristicin was dissolved in 7.800 g of camphor (Kf = 39.7 °\degree C/m) , decreasing the freezing point of camphor by 11.3 °\degree C.What is the molar mass of myristicin?


A) 65.0 g/mol
B) 130.g/mol
C) 191 g/mol
D) 451 g/mol
E) 1070 g/mol

F) C) and D)
G) A) and C)

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What is the osmotic pressure of a 0.0540 M aqueous sodium sulfate (Na2SO4, 142.04 g/mol) solution at 25.0 °\degree C?


A) 1.32 atm
B) 2.64 atm
C) 3.96 atm
D) 134 atm
E) 33.7 atm

F) A) and D)
G) A) and C)

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What is the molality of a lithium chloride solution produced by dissolving 14.40 g of LiCl (42.39 g/mol) in water to make 0.104 L of solution with a density of 1.102 g/mL?


A) 0.340 m
B) 3.39 m
C) 3.27 m
D) 3.74 m
E) 2.96 m

F) A) and C)
G) D) and E)

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A solution of 5.00 g of lithium chloride in 1.00 kg of water has a freezing point of -0.410 °\degree C.What is the actual van 't Hoff factor for this salt at this concentration? (Kf (water) =1.86 °\degree C/m)

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A solution is prepared by mixing 3.50 mL of dichloromethane (CH2Cl2, 84.93 g/mol, 1.33 g/mL) with 3.50 mL of dibromomethane (CH2Br2, 173.8 g/mol, 2.48 g/mL) .By what factor is the vapor phase enriched in CH2Cl2 at 25 °\degree C?  A solution is prepared by mixing 3.50 mL of dichloromethane (CH<sub>2</sub>Cl<sub>2</sub>, 84.93 g/mol, 1.33 g/mL)  with 3.50 mL of dibromomethane (CH<sub>2</sub>Br<sub>2</sub>, 173.8 g/mol, 2.48 g/mL) .By what factor is the vapor phase enriched in CH<sub>2</sub>Cl<sub>2</sub> at 25  \degree C?   A) 35.3 B) 10.8 C) 2.06 D) 1.77 E) 11.7


A) 35.3
B) 10.8
C) 2.06
D) 1.77
E) 11.7

F) C) and E)
G) B) and D)

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A solution contains pentane (C5H12, 72.15 g/mol) and hexane (C6H14, 86.17 g/mol) at 25 °\degree C, which have vapor pressures of 511 and 150 torr, respectively.To create a solution with a total vapor pressure of 275 torr, approximately how many grams of hexane should be mixed with 50.0 g pentane?

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About 113 ...

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The normal boiling point of bromine is 58.8 °\degree C, and its enthalpy of vaporization is 30.91 kJ/mol.What is the approximate vapor pressure of bromine at 10.0 °\degree C?


A) 0.998 atm
B) 0.735 atm
C) 0.853 atm
D) 0.145 atm
E) 6.89 atm

F) C) and D)
G) A) and B)

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Which of the following statements regarding the phase diagram of water and an aqueous solution is NOT correct? Temperature is on the x-axis; pressure is on the y-axis. Which of the following statements regarding the phase diagram of water and an aqueous solution is NOT correct? Temperature is on the x-axis; pressure is on the y-axis.   A) The boiling point of the solution is higher than that of the solvent by an amount indicated by the difference in temperature between points E and F. B) Point D corresponds to the triple point of the solvent. C) The solution boils at the temperature corresponding to point F. D) The normal freezing point of the solution corresponds to point A. E) The freezing point of the solvent is higher than that of the solution.


A) The boiling point of the solution is higher than that of the solvent by an amount indicated by the difference in temperature between points E and F.
B) Point D corresponds to the triple point of the solvent.
C) The solution boils at the temperature corresponding to point F.
D) The normal freezing point of the solution corresponds to point A.
E) The freezing point of the solvent is higher than that of the solution.

F) A) and D)
G) A) and E)

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How many moles of solute are in a 0.174 m aspartic acid (C4H7NO4) solution prepared with 250.0 g of water?


A) 6.96 *10-4 mol
B) 4.35* 10-2 mol
C) 0.696 mol
D) 1.44 mol
E) 43.5 mol

F) All of the above
G) D) and E)

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B

A 50:50 mixture of cyclohexane (C6H12, 84.16 g/mol) and toluene (C6H5CH3, 92.14 °\degree C) are to be separated by fractional distillation.A plot of temperature versus volume of distillate shows two plateaus, one at 80.7 °\degree C and one at 110.6 °\degree C.What is the approximate boiling point of each liquid? Use intermolecular forces to justify your answer.

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The boiling point of C6H12 is probably 80.7 \(\degree\)C.It has a lower molar mass, so the strength of the intermolecular forces should be lower.The boiling point of toluene, which is a larger molecule, is probably 110.6 \(\degree\)C.

Suppose 100.0 mL of a 2.50 mM NaCl solution was mixed with 100.0 mL of a 3.40 mM MgCl2 solution at 25 °\degree C.Assuming the volumes are additive and using the ideal van 't Hoff factors, what would be the osmotic pressure of the resulting solution?

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0.186 atm

Seawater can be characterized by the following average values.What is the molal concentration of ions in seawater? Explain how you arrived at your answer. density = 1.022 g/mL, total mass of ions = 35.17 g/kg concentration of ions =1.15 M

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The molarity gives the moles of ions in ...

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A solution is prepared by mixing 75 g of methanol (CH3OH, 32.04 g/mol) with 25 g of ethanol (CH3CH2OH, 46.07 g/mol) .What is the mole fraction of ethanol in the vapor phase at 20 °\degree C?  A solution is prepared by mixing 75 g of methanol (CH<sub>3</sub>OH, 32.04 g/mol)  with 25 g of ethanol (CH<sub>3</sub>CH<sub>2</sub>OH, 46.07 g/mol) .What is the mole fraction of ethanol in the vapor phase at 20  \degree C?   A) 0.10 B) 0.12 C) 0.19 D) 0.32 E) 0.54


A) 0.10
B) 0.12
C) 0.19
D) 0.32
E) 0.54

F) B) and E)
G) D) and E)

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