Question 1

The vapor pressure of a solution containing a nonvolatile solute is directly proportional to the

Accepted Answer

A) mole fraction of the solvent. 
B) mole fraction of the solute. 
C) molality of the solvent. 
D) molarity of the solvent. 
E) osmotic pressure of the solute.

Question 2

A phase diagram, like the one below, for an aqueous solution shows a shift in the solid/liquid and liquid/gas phase transitions but there is not a shift in the sublimation line between solids and gases. Explain what causes the shift in the other transitions and why this does not change a shift in the solid/gas transition.Hint: Think about the difference in vapor pressure between a solution and a pure substance.

Accepted Answer

The answer of A phase diagram, like the one below,...

Question 3

The CO2 gas sealed inside a carbonated beverage bottle has a pressure of 3.750 atm. At this pressure, the solubility of CO2 in water is 0.65 g CO2/100 g H2O. If the bottle is opened, as the gas in the space above the liquid escapes, the partial pressure of the CO2 falls to 0.30 torr, the value in the surrounding atmosphere of the room. What is the solubility of CO2 in the beverage at this new pressure?Hint: Be sure check your pressure units.

Accepted Answer

A) 5.2 × 10-2 g/100 g H2O 
B) 5.0 × 10-4 g/100 g H2O 
C) 6.7 × 10-5 g/100 g H2O 
D) 6.8 × 10-5 g/100 g H2O 
E) 9.6 × 10-4 g/100 g H2O

Question 4

KBr has a lattice energy of -682 kJ/mol and a hydration energy of -657 kJ/mol. Using this information, what is the heat of solution, $\Delta$Hsol, for KBr?Hint: What happens to the crystal lattice when an ionic compound dissolves?

Accepted Answer

A) -1339 kJ/mol 
B) +1339 kJ/mol 
C) +25 kJ/mol 
D) -657 kJ/mol 
E) +657 kJ/mol

Question 5

Which can be used to calculate the osmotic pressure of a solution?

Accepted Answer

A) de Broglie equation 
B) Tyndall factor 
C) Peters equation 
D) van der Waals equation 
E) van't Hoff equation

Question 6

Pure glacial acetic acid, HC2H3O2, has a freezing point of 16.62°C. Its freezing point depression constant is: Kf = 3.57 °C m-1. A solution was made by taking 9.755 g of an unknown nonelectrolyte and dissolving it in 90.50 g of glacial acetic acid. The measured freezing point of the solution was 8.64°C. Calculate the molecular weight of the unknown substance.Hint: Find molality, then moles, then molar mass, being sure to keep track of units.

Accepted Answer

A) 24.4 g mol-1 
B) 30.5 g mol-1 
C) 45.3 g mol-1 
D) 48.2 g mol-1 
E) 174 g mol-1

Question 7

Liquids that are mutually miscible possess intermolecular forces of similar type and magnitude.

Accepted Answer

A) True 
 B)False

Question 8

A solution in a beaker has some undissolved solute lying on the bottom of the beaker. If the rate of crystallization exceeds the rate of dissolution of the excess solute, the solution is described as

Accepted Answer

A) dilute. 
B) concentrated. 
C) unsaturated. 
D) saturated. 
E) supersaturated.

Question 9

A solution of chloroform (CHCl₃)and acetone ((CH₃)₂CO)exhibits a negative deviation from Raoult's law similar to that shown on the diagram below. What does this tell us about the solution with respect to it being an ideal solution and the strength of the interactions between acetone and chloroform? This result shows us that the solution is ________ ideal and the interactions between chloroform-chloroform and acetone-acetone are ________ than the interactions between chloroform/acetone.

Accepted Answer

The answer of A solution of chloroform (CHCl₃)and acetone ((CH₃)₂CO)exhibits...

Question 10

One driving force toward formation of homogeneous gas mixtures is the spontaneity of mixing through random motion of small molecules.

Accepted Answer

A) True 
 B)False

Question 11

An aqueous solution of glycerol, C3H8O3 is prepared by adding 150.0 g of glycerol to 200.0 g of water. What is the mole fraction of glycerol in the final solution?

Accepted Answer

A) 0.571 
B) 0.429 
C) 0.750 
D) 0.872 
E) 0.128

Question 12

The solubility of O2 in water is approximately 0.00380 g L-1 when the temperature is 25.0°C and the partial pressure of gaseous oxygen is 760. torr. What will the solubility of oxygen be if the oxygen pressure is adjusted to 1000 torr?

Accepted Answer

A) 0.00289 g L-1 
B) 0.00500 g L-1 
C) 1.49 g L-1 
D) 2.89 × 103 g L-1 
E) 3.46 × 103 g L-1

Question 13

Which aqueous solution will have the lowest boiling point temperature?

Accepted Answer

A) 0.100 molal NiBr2(aq) 
B) 0.200 molal MgSO4(aq) 
C) 0.150 molal NH4NO3(aq) 
D) 0.150 molal Na2SO4(aq) 
E) 0.250 molal CH3OH(aq)

Question 14

Which aqueous solution should have the highest osmotic pressure?

Accepted Answer

A) 0.100 molar Al(NO3)3 
B) 0.150 molar Ba(NO3)2 
C) 0.100 molar CaCl2 
D) 0.150 molar NaCl 
E) 0.200 molar NH3

Question 15

Pure benzene, C₆H₆, has a molar mass of 78.114 g mol⁻¹, a density of 0.8765 g mL⁻¹, a freezing point of 5.45°C, and a boiling point of 80.2°C. Its freezing point depression and boiling point elevation constants are: K_f = 5.07 °C m⁻¹; K_b = 2.53 °C m⁻¹. A solution was made by taking 16.00 g of an unknown nonelectrolyte and dissolving it in 168.0 g of benzene. The measured freezing point of the solution was -1.05°C. Calculate the molar mass of the unknown substance.Hint: Find molality, then moles, then molar mass, being sure to keep track of units.

Accepted Answer

The answer of Pure benzene, C₆H₆, has a molar mass...

Question 16

How many grams of water are needed to dissolve 13.9 g of ammonium nitrate NH₄NO₃ in order to prepare a 0.452 m solution?

Accepted Answer

The answer of How many grams of water are needed...

Question 17

A solution is prepared by mixing 0.3355 moles of NaNO3 (84.995 g mol-1)with 235.0 g of water (18.015 g mol-1). Its density is 1.0733 g mL-1. What is the percent by mass of NaNO3 in the solution?

Accepted Answer

A) 10.16% 
B) 10.82% 
C) 11.61% 
D) 14.19% 
E) 26.56%

Question 18

What is the normal boiling point of a solution that contains 30.0 g of glucose (C6H12O6)in 100.0 g of H2O? Kb for water is 0.512°C/m.

Accepted Answer

A) 0.17°C 
B) 99.01°C 
C) 101.67°C 
D) 100.85°C 
E) 101.53°C

Question 19

Pure cyclohexane, C₆H₁₂, has a molar mass of 84.161 g mol⁻¹, a density of 0.7785 g mL⁻¹, a freezing point of 6.53°C, and a boiling point of 80.72°C. Its freezing point depression and boiling point elevation constants are: K_f = 20.0 °C m⁻¹; K_b = 2.69 °C m⁻¹. A solution was made by taking 9.50 g of an unknown nonelectrolyte and dissolving it in 125.0 g of cyclohexane. The measured freezing point of the solution was -0.78^°C. Calculate the molar mass of the unknown substance.Hint: Find molality, then moles, then molar mass, being sure to keep track of units.

Accepted Answer

The answer of Pure cyclohexane, C₆H₁₂, has a molar mass...

Question 20

Raoult's law expresses that the higher the mole fraction of a volatile solvent in an ideal solution the ________ its partial pressure above the solution.

Accepted Answer

The answer of Raoult's law expresses that the higher the...

Exam 13: Mixtures at the Molecular Level: Properties of Solutions

The vapor pressure of a solution containing a nonvolatile solute is directly proportional to the

KBr has a lattice energy of -682 kJ/mol and a hydration energy of -657 kJ/mol. Using this information, what is the heat of solution, $\Delta$ H_sol, for KBr?Hint: What happens to the crystal lattice when an ionic compound dissolves?

Which can be used to calculate the osmotic pressure of a solution?

Liquids that are mutually miscible possess intermolecular forces of similar type and magnitude.

A solution in a beaker has some undissolved solute lying on the bottom of the beaker. If the rate of crystallization exceeds the rate of dissolution of the excess solute, the solution is described as

One driving force toward formation of homogeneous gas mixtures is the spontaneity of mixing through random motion of small molecules.

An aqueous solution of glycerol, C₃H₈O₃ is prepared by adding 150.0 g of glycerol to 200.0 g of water. What is the mole fraction of glycerol in the final solution?

The solubility of O₂ in water is approximately 0.00380 g L^-1 when the temperature is 25.0°C and the partial pressure of gaseous oxygen is 760. torr. What will the solubility of oxygen be if the oxygen pressure is adjusted to 1000 torr?

Which aqueous solution will have the lowest boiling point temperature?

Which aqueous solution should have the highest osmotic pressure?

How many grams of water are needed to dissolve 13.9 g of ammonium nitrate NH₄NO₃ in order to prepare a 0.452 m solution?

A solution is prepared by mixing 0.3355 moles of NaNO₃ (84.995 g mol^-1) with 235.0 g of water (18.015 g mol^-1) . Its density is 1.0733 g mL^-1. What is the percent by mass of NaNO₃ in the solution?

What is the normal boiling point of a solution that contains 30.0 g of glucose (C₆H₁₂O₆) in 100.0 g of H₂O? K_b for water is 0.512°C/m.

Raoult's law expresses that the higher the mole fraction of a volatile solvent in an ideal solution the ________ its partial pressure above the solution.

Exam 13: Mixtures at the Molecular Level: Properties of Solutions

The vapor pressure of a solution containing a nonvolatile solute is directly proportional to the

KBr has a lattice energy of -682 kJ/mol and a hydration energy of -657 kJ/mol. Using this information, what is the heat of solution, Δ\DeltaΔ Hsol, for KBr?Hint: What happens to the crystal lattice when an ionic compound dissolves?

Which can be used to calculate the osmotic pressure of a solution?

Liquids that are mutually miscible possess intermolecular forces of similar type and magnitude.

A solution in a beaker has some undissolved solute lying on the bottom of the beaker. If the rate of crystallization exceeds the rate of dissolution of the excess solute, the solution is described as

One driving force toward formation of homogeneous gas mixtures is the spontaneity of mixing through random motion of small molecules.

An aqueous solution of glycerol, C3H8O3 is prepared by adding 150.0 g of glycerol to 200.0 g of water. What is the mole fraction of glycerol in the final solution?

The solubility of O2 in water is approximately 0.00380 g L-1 when the temperature is 25.0°C and the partial pressure of gaseous oxygen is 760. torr. What will the solubility of oxygen be if the oxygen pressure is adjusted to 1000 torr?

Which aqueous solution will have the lowest boiling point temperature?

Which aqueous solution should have the highest osmotic pressure?

How many grams of water are needed to dissolve 13.9 g of ammonium nitrate NH4NO3 in order to prepare a 0.452 m solution?

A solution is prepared by mixing 0.3355 moles of NaNO3 (84.995 g mol-1) with 235.0 g of water (18.015 g mol-1) . Its density is 1.0733 g mL-1. What is the percent by mass of NaNO3 in the solution?

What is the normal boiling point of a solution that contains 30.0 g of glucose (C6H12O6) in 100.0 g of H2O? Kb for water is 0.512°C/m.

Raoult's law expresses that the higher the mole fraction of a volatile solvent in an ideal solution the ________ its partial pressure above the solution.

KBr has a lattice energy of -682 kJ/mol and a hydration energy of -657 kJ/mol. Using this information, what is the heat of solution, $\Delta$ H_sol, for KBr?Hint: What happens to the crystal lattice when an ionic compound dissolves?

An aqueous solution of glycerol, C₃H₈O₃ is prepared by adding 150.0 g of glycerol to 200.0 g of water. What is the mole fraction of glycerol in the final solution?

The solubility of O₂ in water is approximately 0.00380 g L^-1 when the temperature is 25.0°C and the partial pressure of gaseous oxygen is 760. torr. What will the solubility of oxygen be if the oxygen pressure is adjusted to 1000 torr?

How many grams of water are needed to dissolve 13.9 g of ammonium nitrate NH₄NO₃ in order to prepare a 0.452 m solution?

A solution is prepared by mixing 0.3355 moles of NaNO₃ (84.995 g mol^-1) with 235.0 g of water (18.015 g mol^-1) . Its density is 1.0733 g mL^-1. What is the percent by mass of NaNO₃ in the solution?

What is the normal boiling point of a solution that contains 30.0 g of glucose (C₆H₁₂O₆) in 100.0 g of H₂O? K_b for water is 0.512°C/m.