Question 1

Which of the following aqueous solutions has the largest molality of benzoic acid (C6H5COOH)

Accepted Answer

A)  3.5 m C6H5COOH 
B)  mole fraction, X = 0.050 C6H5COOH 
C)  2.50 mass % C6H5COOH 
D)  3.2 g C6H5COOH in 650. g of H2O 
E)  1.5 moles C6H5COOH in 65.0 moles of H2O 
A)  3.5 m C6H5COOH 
B)  mole fraction, X = 0.050 C6H5COOH 
C)  2.50 mass % C6H5COOH 
D)  3.2 g C6H5COOH in 650. g of H2O 
E)  1.5 moles C6H5COOH in 65.0 moles of H2O

Question 2

What is the molarity and molality of a solution that is 10.00 % by mass potassium hydrogen carbonate (KHCO3, 100.11 g/mol) and has a density of 1.0650 g/mL

Accepted Answer

A)  1.064 M and 1.410 m 
B)  1.044 M and 1.410 m 
C)  1.064 M and 1.110 m 
D)  1.044 M and 1.110 m 
E)  None of the above 
A)  1.064 M and 1.410 m 
B)  1.044 M and 1.410 m 
C)  1.064 M and 1.110 m 
D)  1.044 M and 1.110 m 
E)  None of the above

Question 3

A solution is prepared by adding 40.3 g of Mg(NO3)2 to 127 g of water. Calculate the mole fraction and molality of magnesium nitrate in this solution.

Accepted Answer

A)  Mole fraction = 0.0371; molality = 2.14 m 
B)  Mole fraction = 0.0571; molality = 2.14 m 
C)  Mole fraction = 0.0371; molality = 1.14 m 
D)  Mole fraction = 0.0571; molality = 1.14 m 
E)  None of the above 
A)  Mole fraction = 0.0371; molality = 2.14 m 
B)  Mole fraction = 0.0571; molality = 2.14 m 
C)  Mole fraction = 0.0371; molality = 1.14 m 
D)  Mole fraction = 0.0571; molality = 1.14 m 
E)  None of the above

Question 4

Calculate the molality of 6.0 M H2SO4 solution. The density of the solution is 1.34 g/mL.

Accepted Answer

A)  4.48 m 
B)  7.98 m 
C)  8.10 m 
D)  8.43 m 
E)  10.2 m 
A)  4.48 m 
B)  7.98 m 
C)  8.10 m 
D)  8.43 m 
E)  10.2 m

Question 5

What is the osmotic pressure of a solution prepared from 13.7 g of the electrolyte HCl and enough water to make 0.500 L of solution at 18$\circ$C

Accepted Answer

A)  0.55 atm 
B)  1.10 atm 
C)  8.95 atm 
D)  17.9 atm 
E)  35.9 atm 
A)  0.55 atm 
B)  1.10 atm 
C)  8.95 atm 
D)  17.9 atm 
E)  35.9 atm

Question 6

0.102 g of an unknown compound dissolved in 100. mL of water has an osmotic pressure of 28.1 mmHg at 20$\circ$C. Calculate the molar mass of the compound.

Accepted Answer

A)  727 g/mol 
B)  663 g/mol 
C)  1.10 * 102 g/mol 
D)  1.15 g/mol 
E)  0.872 g/mol 
A)  727 g/mol 
B)  663 g/mol 
C)  1.10 * 102 g/mol 
D)  1.15 g/mol 
E)  0.872 g/mol

Question 7

The vapor pressure of water at 45.0 $\circ$C is 71.93 mmHg. Calculate the vapor pressure of a solution of 1.50m K2CO3 at this temperature (assume 100% dissociation).

Accepted Answer

A)  1.89 mmHg 
B)  5.39 mmHg 
C)  66.5 mmHg 
D)  70.0 mmHg 
E)  108 mmHg 
A)  1.89 mmHg 
B)  5.39 mmHg 
C)  66.5 mmHg 
D)  70.0 mmHg 
E)  108 mmHg

Question 8

Calculate the molality of a 15.0% by mass solution of MgCl2 in H2O. The density of this solution is 1.127 g/mL.

Accepted Answer

A)  0.0134 m 
B)  0.157 m 
C)  1.58 m 
D)  1.86 m 
E)  11.8 m 
A)  0.0134 m 
B)  0.157 m 
C)  1.58 m 
D)  1.86 m 
E)  11.8 m

Question 9

The heat of solution

Accepted Answer

A) is never positive $(\Delta{H}^{\circ}_{soln} \leq 0)$, because the solute-solvent attraction is never weaker than the combination of the solute-solute attraction and solvent-solvent attraction. B) is always positive $(\Delta{H}^{\circ}_{soln} > 0)$, because the solute-solvent attraction is always weaker than the combination of the solute-solute attraction and solvent-solvent attraction. C) is always zero ($\Delta$H$\circ$ soln = 0), because the solute-solvent attraction is defined as the average of the solute-solute attraction and solvent-solvent attraction. D) is always negative $(\Delta{H}^{\circ}_{soln} < 0)$, because the solute-solvent attraction is always stronger than the combination of the solute-solute attraction and solvent-solvent attraction. E) may be positive, zero, or negative, depending on the relative strength of the solute-solvent, solute-solute, and solvent-solvent attractive forces. A) is never positive $(\Delta{H}^{\circ}_{soln} \leq 0)$, because the solute-solvent attraction is never weaker than the combination of the solute-solute attraction and solvent-solvent attraction. B) is always positive $(\Delta{H}^{\circ}_{soln} > 0)$, because the solute-solvent attraction is always weaker than the combination of the solute-solute attraction and solvent-solvent attraction. C) is always zero ($\Delta$H$\circ$ soln = 0), because the solute-solvent attraction is defined as the average of the solute-solute attraction and solvent-solvent attraction. D) is always negative $(\Delta{H}^{\circ}_{soln} < 0)$, because the solute-solvent attraction is always stronger than the combination of the solute-solute attraction and solvent-solvent attraction. E) may be positive, zero, or negative, depending on the relative strength of the solute-solvent, solute-solute, and solvent-solvent attractive forces.

Question 10

Calculate the approximate freezing point of a solution made from 21.0 g NaCl and 1.00 * 102 g of H2O. [Kf of water is 1.86$\circ$C/m.]

Accepted Answer

A)  -13.4$\circ$C 
B)  -6.68$\circ$C 
C)  -3.59$\circ$C 
D)  3.59$\circ$C 
E)  6.68$\circ$C 
A)  -13.4$\circ$C 
B)  -6.68$\circ$C 
C)  -3.59$\circ$C 
D)  3.59$\circ$C 
E)  6.68$\circ$C

Question 11

A solution made of pentane and hexane has a mole fraction, X = 0.250 of pentane. Hexane is the solvent.

Accepted Answer

A) True 
 B)False

Question 12

A solution is 35.0% by mass carbon tetrachloride (CCl4) in benzene (C6H6) 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)  58.1 mmHg 
B)  78.2 mmHg 
C)  80.5 mmHg 
D)  82.9 mmHg 
E)  83.0 mmHg 
A)  58.1 mmHg 
B)  78.2 mmHg 
C)  80.5 mmHg 
D)  82.9 mmHg 
E)  83.0 mmHg

Question 13

Determine the mass percent HCl in a 1.2 M solution of hydrochloric acid with a density of 1.019 g/mL.

Accepted Answer

A)  3.0 % 
B)  4.3 % 
C)  8.6 % 
D)  13% 
E)  30. % 
A)  3.0 % 
B)  4.3 % 
C)  8.6 % 
D)  13% 
E)  30. %

Question 14

The solubility of oxygen in lakes high in the Rocky Mountains is affected by the altitude. If the solubility of O2 from the air is 2.67 * 10-4 M at sea level and 25$\circ$C, what is the solubility of O2 at an elevation of 12,000 ft where the atmospheric pressure is 0.657 atm Assume the temperature is 25$\circ$C, and that the mole fraction of O2 in air is 0.209 at both 12,000 ft and at sea level.

Accepted Answer

A)  3.66 * 10-5 M 
B)  1.75 * 10-4 M 
C)  2.67 * 10-4 M 
D)  4.06 * 10-4 M 
E)  None of the above. 
A)  3.66 * 10-5 M 
B)  1.75 * 10-4 M 
C)  2.67 * 10-4 M 
D)  4.06 * 10-4 M 
E)  None of the above.

Question 15

A solution that is 33.6 % by mass of phenol (C6H5OH) in water is prepared. What is the mole fraction of the phenol

Accepted Answer

A)  0.0969 
B)  0.0643 
C)  0.0883 
D)  0.0604 
E)  0.357 
A)  0.0969 
B)  0.0643 
C)  0.0883 
D)  0.0604 
E)  0.357

Question 16

Using your knowledge of osmosis or osmotic pressure decide if the following statement is true or false:
-When sprinkled with sugar, a dish of sliced fruit will form its own juice.

Accepted Answer

A) True 
 B)False

Question 17

What is the concentration of O2(g) in water at 25$\circ$C exposed to a partial pressure of oxygen of 325 mmHg The Henry's law constant for oxygen gas at 25$\circ$C is 1.3 * 10-3 mol/L·atm.

Accepted Answer

A)  1.6 * 10-4 M 
B)  3.6 * 10-4 M 
C)  5.6 * 10-4 M 
D)  7.6 * 10-4 M 
E)  None of the above 
A)  1.6 * 10-4 M 
B)  3.6 * 10-4 M 
C)  5.6 * 10-4 M 
D)  7.6 * 10-4 M 
E)  None of the above

Question 18

Arrange the following aqueous solutions in order of increasing boiling points: 0.050m Mg(NO3)2; 0.100m ethanol; 0.090m NaCl.

Accepted Answer

A)  Mg(NO3)2 3)2 3)2 
D)  NaCl 3)2 
E)  Mg(NO3)2 < ethanol < NaCl 
A)  Mg(NO3)2 3)2 3)2 
D)  NaCl 3)2 
E)  Mg(NO3)2 < ethanol < NaCl

Question 19

What is the freezing point of a solution that contains 10.0 g of glucose (C6H12O6) in 100.g of H2O Kf for water is 1.86$\circ$C/m.

Accepted Answer

A)  +0.10$\circ$C 
B)  +0.186$\circ$C 
C)  -0.10$\circ$C 
D)  -0.186$\circ$C 
E)  -1.03$\circ$C 
A)  +0.10$\circ$C 
B)  +0.186$\circ$C 
C)  -0.10$\circ$C 
D)  -0.186$\circ$C 
E)  -1.03$\circ$C

Question 20

The density of a 20.3 M CH3OH (methanol) solution is 0.858 g/mL. What is the molality of this solution H2O is the solvent.

Accepted Answer

A)  17.4 m 
B)  20.8 m 
C)  23.7 m 
D)  70.0 m 
E)  97.6 m 
A)  17.4 m 
B)  20.8 m 
C)  23.7 m 
D)  70.0 m 
E)  97.6 m

Exam 12: Physical Properties of Solutions

Which of the following aqueous solutions has the largest molality of benzoic acid (C6H5COOH)

What is the molarity and molality of a solution that is 10.00 % by mass potassium hydrogen carbonate (KHCO3, 100.11 g/mol) and has a density of 1.0650 g/mL

A solution is prepared by adding 40.3 g of Mg(NO3)2 to 127 g of water. Calculate the mole fraction and molality of magnesium nitrate in this solution.

Calculate the molality of 6.0 M H2SO4 solution. The density of the solution is 1.34 g/mL.

What is the osmotic pressure of a solution prepared from 13.7 g of the electrolyte HCl and enough water to make 0.500 L of solution at 18 ∘\circ∘ C

0.102 g of an unknown compound dissolved in 100. mL of water has an osmotic pressure of 28.1 mmHg at 20 ∘\circ∘ C. Calculate the molar mass of the compound.

The vapor pressure of water at 45.0 ∘\circ∘ C is 71.93 mmHg. Calculate the vapor pressure of a solution of 1.50m K2CO3 at this temperature (assume 100% dissociation).

Calculate the molality of a 15.0% by mass solution of MgCl2 in H2O. The density of this solution is 1.127 g/mL.

The heat of solution

Calculate the approximate freezing point of a solution made from 21.0 g NaCl and 1.00 * 102 g of H2O. [Kf of water is 1.86 ∘\circ∘ C/m.]

A solution made of pentane and hexane has a mole fraction, X = 0.250 of pentane. Hexane is the solvent.

A solution is 35.0% by mass carbon tetrachloride (CCl4) in benzene (C6H6) 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:

Determine the mass percent HCl in a 1.2 M solution of hydrochloric acid with a density of 1.019 g/mL.

A solution that is 33.6 % by mass of phenol (C6H5OH) in water is prepared. What is the mole fraction of the phenol

Using your knowledge of osmosis or osmotic pressure decide if the following statement is true or false: -When sprinkled with sugar, a dish of sliced fruit will form its own juice.

What is the concentration of O2(g) in water at 25 ∘\circ∘ C exposed to a partial pressure of oxygen of 325 mmHg The Henry's law constant for oxygen gas at 25 ∘\circ∘ C is 1.3 * 10-3 mol/L·atm.

Arrange the following aqueous solutions in order of increasing boiling points: 0.050m Mg(NO3)2; 0.100m ethanol; 0.090m NaCl.

What is the freezing point of a solution that contains 10.0 g of glucose (C6H12O6) in 100.g of H2O Kf for water is 1.86 ∘\circ∘ C/m.

The density of a 20.3 M CH3OH (methanol) solution is 0.858 g/mL. What is the molality of this solution H2O is the solvent.

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

Which of the following aqueous solutions has the largest molality of benzoic acid (C₆H₅COOH)

What is the molarity and molality of a solution that is 10.00 % by mass potassium hydrogen carbonate (KHCO₃, 100.11 g/mol) and has a density of 1.0650 g/mL

A solution is prepared by adding 40.3 g of Mg(NO₃)₂ to 127 g of water. Calculate the mole fraction and molality of magnesium nitrate in this solution.

Calculate the molality of 6.0 M H₂SO₄ solution. The density of the solution is 1.34 g/mL.

What is the osmotic pressure of a solution prepared from 13.7 g of the electrolyte HCl and enough water to make 0.500 L of solution at 18^$\circ$C

0.102 g of an unknown compound dissolved in 100. mL of water has an osmotic pressure of 28.1 mmHg at 20^$\circ$C. Calculate the molar mass of the compound.

The vapor pressure of water at 45.0 ^$\circ$C is 71.93 mmHg. Calculate the vapor pressure of a solution of 1.50m K₂CO₃ at this temperature (assume 100% dissociation).

Calculate the molality of a 15.0% by mass solution of MgCl₂ in H₂O. The density of this solution is 1.127 g/mL.

Calculate the approximate freezing point of a solution made from 21.0 g NaCl and 1.00 * 10² g of H₂O. [K_f of water is 1.86^$\circ$C/m.]

A solution is 35.0% by mass carbon tetrachloride (CCl₄) in benzene (C₆H₆) 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:

A solution that is 33.6 % by mass of phenol (C₆H₅OH) in water is prepared. What is the mole fraction of the phenol

What is the concentration of O₂(g) in water at 25^$\circ$C exposed to a partial pressure of oxygen of 325 mmHg The Henry's law constant for oxygen gas at 25^$\circ$C is 1.3 * 10^-3 mol/L·atm.

Arrange the following aqueous solutions in order of increasing boiling points: 0.050m Mg(NO₃)₂; 0.100m ethanol; 0.090m NaCl.

What is the freezing point of a solution that contains 10.0 g of glucose (C₆H₁₂O₆) in 100.g of H₂O K_f for water is 1.86^$\circ$C/m.

The density of a 20.3 M CH₃OH (methanol) solution is 0.858 g/mL. What is the molality of this solution H₂O is the solvent.