Question 1

What is the percent by mass of a Na2SO4 solution in water with a mole fraction of Na2SO4, X = 0.350

Accepted Answer

A)  2.76% 
B)  4.25% 
C)  19.1% 
D)  73.4 % 
E)  80.9% 
A)  2.76% 
B)  4.25% 
C)  19.1% 
D)  73.4 % 
E)  80.9%

Question 2

When 20.0 grams of an unknown compound are dissolved in 500. grams of benzene, the freezing point of the resulting solution is 3.77$\circ$C. The freezing point of pure benzene is 5.444$\circ$C, and the Kf for benzene is 5.12$\circ$C/m. What is the molar mass of the unknown compound

Accepted Answer

A)  110 g/mol 
B)  120 g/mol 
C)  130 g/mol 
D)  140 g/mol 
E)  None of the above 
A)  110 g/mol 
B)  120 g/mol 
C)  130 g/mol 
D)  140 g/mol 
E)  None of the above

Question 3

What is the osmotic pressure of a 0.25 M solution of sucrose at 37$\circ$C (R = 0.0821 L·atm/K·mol)

Accepted Answer

A)  6.6 * 10-5 atm 
B)  0.76 atm 
C)  6.4 atm 
D)  100 atm 
E)  940 atm 
A)  6.6 * 10-5 atm 
B)  0.76 atm 
C)  6.4 atm 
D)  100 atm 
E)  940 atm

Question 4

What is the molality of an aqueous KBr solution with a mole fraction of KBr, X, equal to 0.245

Accepted Answer

A)  0.325 m 
B)  0.682 m 
C)  13.6 m 
D)  18.0 m 
E)  29.2 m 
A)  0.325 m 
B)  0.682 m 
C)  13.6 m 
D)  18.0 m 
E)  29.2 m

Question 5

A 1.35 m solution of NaOCl in water is prepared. What is the mole fraction of the NaOCl

Accepted Answer

A)  0.0135 
B)  0.0243 
C)  0.0271 
D)  0.0237 
E)  0.0263 
A)  0.0135 
B)  0.0243 
C)  0.0271 
D)  0.0237 
E)  0.0263

Question 6

The vapor pressure of water at 20$\circ$C is 17.5 mmHg. What is the vapor pressure of water over a solution prepared from 2.00 * 102 g of sucrose (C12H22O11) and 3.50 * 102 g water

Accepted Answer

A)  0.51 mmHg 
B)  16.0 mmHg 
C)  17.0 mmHg 
D)  18.0 mmHg 
E)  19.4 mmHg 
A)  0.51 mmHg 
B)  16.0 mmHg 
C)  17.0 mmHg 
D)  18.0 mmHg 
E)  19.4 mmHg

Question 7

List the following solutions in order of decreasing melting point: 0.20m glycerol, 0.11m Sc(NO3)3, 0.15m K2CO3

Accepted Answer

A)  glycerol > K2CO 3> Sc(NO3)3 
B)  glycerol > Sc(NO3)3 > K2CO3 
C)  Sc(NO3)3 > glycerol > K2CO3 
D)  Sc(NO3)3 > K2CO3 > glycerol 
E)  None of the above 
A)  glycerol > K2CO 3> Sc(NO3)3 
B)  glycerol > Sc(NO3)3 > K2CO3 
C)  Sc(NO3)3 > glycerol > K2CO3 
D)  Sc(NO3)3 > K2CO3 > glycerol 
E)  None of the above

Question 8

The vapor pressure of a solution depends on the chemical nature of the non-volatile solute.

Accepted Answer

A) True 
 B)False

Question 9

Which of the following compounds should be soluble in CCl4

Accepted Answer

A)  NaCl 
B)  H2O 
C)  NaOH 
D)  C8H18 
E)  None of these 
A)  NaCl 
B)  H2O 
C)  NaOH 
D)  C8H18 
E)  None of these

Question 10

Assuming 100% dissociation, which of the following compounds is listed incorrectly with its van't Hoff factor i

Accepted Answer

A)  Na2SO4, i = 3 
B)  NH4NO3, i = 2 
C)  Sucrose, i = 1 
D)  Al2(SO4)3, i = 4 
E)  Mg(NO3)2, i = 3 
A)  Na2SO4, i = 3 
B)  NH4NO3, i = 2 
C)  Sucrose, i = 1 
D)  Al2(SO4)3, i = 4 
E)  Mg(NO3)2, i = 3

Question 11

When 24.0 g of glucose (a nonelectrolyte) is dissolved in 500. g of water, the solution has a freezing point of -0.47$\circ$C. What is the molar mass of glucose Kf of water is 1.86$\circ$C/m.

Accepted Answer

A)  41.9 g/mol 
B)  47.5 g/mol 
C)  54.9 g/mol 
D)  178 g/mol 
E)  190. g/mol 
A)  41.9 g/mol 
B)  47.5 g/mol 
C)  54.9 g/mol 
D)  178 g/mol 
E)  190. g/mol

Question 12

To interconvert the concentration units of molality (m) and mass percent, you must also know the density of the solution.

Accepted Answer

A) True 
 B)False

Question 13

What is the molality of a 0.142 M Na3PO4(aq) solution that has a density of 1.015 g/mL

Accepted Answer

A)  0.113 m 
B)  0.133 m 
C)  0.153 m 
D)  0.173 m 
E)  None of the above 
A)  0.113 m 
B)  0.133 m 
C)  0.153 m 
D)  0.173 m 
E)  None of the above

Question 14

Calculate the molality of a 20.0% by mass ammonium sulfate (NH4)2SO4 solution. The density of the solution is 1.117 g/mL.

Accepted Answer

A)  0.150 m 
B)  1.51 m 
C)  1.70 m 
D)  1.89 m 
E)  2.10 m 
A)  0.150 m 
B)  1.51 m 
C)  1.70 m 
D)  1.89 m 
E)  2.10 m

Question 15

The term "proof" is defined as twice the percent by volume of pure ethanol in solution. A solution that is 95% ethanol is 190 proof. What is the molarity of ethanol in a 92-proof ethanol/water solution (Given: density of ethanol = 0.80 g/cm3; density of water = 1.0 g/cm3)

Accepted Answer

A)  8.8 M 
B)  8.4 M 
C)  8.2 M 
D)  8.0 M 
E)  None of the above 
A)  8.8 M 
B)  8.4 M 
C)  8.2 M 
D)  8.0 M 
E)  None of the above

Question 16

Which of the following aqueous solutions has the highest osmotic pressure at 25$\circ$C (assume 100% dissociation for all soluble ionic compounds)

Accepted Answer

A)  0.15m K3PO4 
B)  0.20m KI 
C)  0.25m K2CO3 
D)  0.30m NH4NO3 
E)  0.45m C12H22O11 
A)  0.15m K3PO4 
B)  0.20m KI 
C)  0.25m K2CO3 
D)  0.30m NH4NO3 
E)  0.45m C12H22O11

Question 17

A saturated solution

Accepted Answer

A)  contains more solute than solvent. 
B)  contains more solvent than solute. 
C)  contains equal moles of solute and solvent. 
D)  contains the maximum amount of solute that will dissolve in that solvent at that temperature. 
E)  contains a solvent with only sigma bonds and no pi bonds (i.e. only single bonds, with no double or triple bonds). 
A)  contains more solute than solvent. 
B)  contains more solvent than solute. 
C)  contains equal moles of solute and solvent. 
D)  contains the maximum amount of solute that will dissolve in that solvent at that temperature. 
E)  contains a solvent with only sigma bonds and no pi bonds (i.e. only single bonds, with no double or triple bonds).

Question 18

Some KCl is dissolved in water at 25$\circ$C, where it completely dissociates. The vapor pressure of pure water at 25$\circ$C is 28.3 mmHg. Estimate the mass in grams of KCl needed per liter of pure water to reduce the vapor pressure of water at 25$\circ$C by 5%.

Accepted Answer

A)  110 g 
B)  120 g 
C)  130 g 
D)  140 g 
E)  None of the above 
A)  110 g 
B)  120 g 
C)  130 g 
D)  140 g 
E)  None of the above

Question 19

A solution is 40.0% by mass benzene (C6H6) in carbon tetrachloride (CCl4) at 20$\circ$C. The vapor pressure of pure benzene and pure carbon tetrachloride at this temperature is 74.61 mmHg and 91.32 mmHg, respectively. Calculate the vapor pressure of the solution at 20$\circ$C:

Accepted Answer

A)  66.4 mmHg 
B)  73.8 mmHg 
C)  81.8 mmHg 
D)  83.0 mmHg 
E)  84.6 mmHg 
A)  66.4 mmHg 
B)  73.8 mmHg 
C)  81.8 mmHg 
D)  83.0 mmHg 
E)  84.6 mmHg

Question 20

What is the mole fraction of NaOH in a 32.0 % by mass NaOH aqueous solution

Accepted Answer

A)  0.105 
B)  0.135 
C)  0.155 
D)  0.175 
E)  None of the above 
A)  0.105 
B)  0.135 
C)  0.155 
D)  0.175 
E)  None of the above

Exam 12: Physical Properties of Solutions

What is the percent by mass of a Na2SO4 solution in water with a mole fraction of Na2SO4, X = 0.350

What is the osmotic pressure of a 0.25 M solution of sucrose at 37 ∘\circ∘ C (R = 0.0821 L·atm/K·mol)

What is the molality of an aqueous KBr solution with a mole fraction of KBr, X, equal to 0.245

A 1.35 m solution of NaOCl in water is prepared. What is the mole fraction of the NaOCl

The vapor pressure of water at 20 ∘\circ∘ C is 17.5 mmHg. What is the vapor pressure of water over a solution prepared from 2.00 * 102 g of sucrose (C12H22O11) and 3.50 * 102 g water

List the following solutions in order of decreasing melting point: 0.20m glycerol, 0.11m Sc(NO3)3, 0.15m K2CO3

The vapor pressure of a solution depends on the chemical nature of the non-volatile solute.

Which of the following compounds should be soluble in CCl4

Assuming 100% dissociation, which of the following compounds is listed incorrectly with its van't Hoff factor i

When 24.0 g of glucose (a nonelectrolyte) is dissolved in 500. g of water, the solution has a freezing point of -0.47 ∘\circ∘ C. What is the molar mass of glucose Kf of water is 1.86 ∘\circ∘ C/m.

To interconvert the concentration units of molality (m) and mass percent, you must also know the density of the solution.

What is the molality of a 0.142 M Na3PO4(aq) solution that has a density of 1.015 g/mL

Calculate the molality of a 20.0% by mass ammonium sulfate (NH4)2SO4 solution. The density of the solution is 1.117 g/mL.

The term "proof" is defined as twice the percent by volume of pure ethanol in solution. A solution that is 95% ethanol is 190 proof. What is the molarity of ethanol in a 92-proof ethanol/water solution (Given: density of ethanol = 0.80 g/cm3; density of water = 1.0 g/cm3)

Which of the following aqueous solutions has the highest osmotic pressure at 25 ∘\circ∘ C (assume 100% dissociation for all soluble ionic compounds)

A saturated solution

Some KCl is dissolved in water at 25 ∘\circ∘ C, where it completely dissociates. The vapor pressure of pure water at 25 ∘\circ∘ C is 28.3 mmHg. Estimate the mass in grams of KCl needed per liter of pure water to reduce the vapor pressure of water at 25 ∘\circ∘ C by 5%.

A solution is 40.0% by mass benzene (C6H6) in carbon tetrachloride (CCl4) at 20 ∘\circ∘ C. The vapor pressure of pure benzene and pure carbon tetrachloride at this temperature is 74.61 mmHg and 91.32 mmHg, respectively. Calculate the vapor pressure of the solution at 20 ∘\circ∘ C:

What is the mole fraction of NaOH in a 32.0 % by mass NaOH aqueous solution

Chemistry: The Study of Change

Atoms Molecules and Ions

Mass Relationships in Chemical Reactions

Reactions in Aqueous Solutions

Gases

Thermochemistry

Quantum Theory and the Electronic Structure of Atoms

Periodic Relationships Among the Elements

Chemical Bonding I: Basic Concepts

Chemical Bonding II: Molecular Geometry and Hybridization of Atomic

Intermolecular Forces and Liquids and Solids

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

Acid-Base Equilibria and Solubility Equilibria

Entropy Free Energy and Equilibrium

Electrochemistry

Nuclear Chemistry

Chemistry in the Atmosphere

Metallurgy and the Chemistry of Metals

Nonmetallic Elements and Their Compounds

Transition Metals Chemistry and Coordination Compounds

Organic Chemistry

Synthetic and Natural Organic Polymers

Filters

What is the percent by mass of a Na₂SO₄ solution in water with a mole fraction of Na₂SO₄, X = 0.350

What is the osmotic pressure of a 0.25 M solution of sucrose at 37^$\circ$C (R = 0.0821 L·atm/K·mol)

The vapor pressure of water at 20^$\circ$C is 17.5 mmHg. What is the vapor pressure of water over a solution prepared from 2.00 * 10² g of sucrose (C₁₂H₂₂O₁₁) and 3.50 * 10² g water

List the following solutions in order of decreasing melting point: 0.20m glycerol, 0.11m Sc(NO₃)₃, 0.15m K₂CO₃

Which of the following compounds should be soluble in CCl₄

When 24.0 g of glucose (a nonelectrolyte) is dissolved in 500. g of water, the solution has a freezing point of -0.47^$\circ$C. What is the molar mass of glucose K_f of water is 1.86^$\circ$C/m.

What is the molality of a 0.142 M Na₃PO₄(aq) solution that has a density of 1.015 g/mL

Calculate the molality of a 20.0% by mass ammonium sulfate (NH₄)₂SO₄ solution. The density of the solution is 1.117 g/mL.

The term "proof" is defined as twice the percent by volume of pure ethanol in solution. A solution that is 95% ethanol is 190 proof. What is the molarity of ethanol in a 92-proof ethanol/water solution (Given: density of ethanol = 0.80 g/cm³; density of water = 1.0 g/cm³)

Which of the following aqueous solutions has the highest osmotic pressure at 25^$\circ$C (assume 100% dissociation for all soluble ionic compounds)

Some KCl is dissolved in water at 25^$\circ$C, where it completely dissociates. The vapor pressure of pure water at 25^$\circ$C is 28.3 mmHg. Estimate the mass in grams of KCl needed per liter of pure water to reduce the vapor pressure of water at 25^$\circ$C by 5%.

A solution is 40.0% by mass benzene (C₆H₆) in carbon tetrachloride (CCl₄) at 20^$\circ$C. The vapor pressure of pure benzene and pure carbon tetrachloride at this temperature is 74.61 mmHg and 91.32 mmHg, respectively. Calculate the vapor pressure of the solution at 20^$\circ$C: