Question 1

At a given temperature the vapor pressures of benzene and toluene are 183 mm Hg and 59.2 mm Hg,respectively.Calculate the mole fraction of benzene in the vapor phase over a solution of benzene and toluene with Xbenzene = 0.600.

Accepted Answer

A) 0)600 
B) 0)678 
C) 0)756 
D) 0)823

Question 2

Arrows in the energy diagram below represent enthalpy changes occurring in the exothermic formation of a solution:
ΔHS1U1B1solnS1U1B0 = enthalpy of solution
ΔHsolute-solute = enthalpy change involving solute-solute interactions
ΔHsolute-solvent = enthalpy change involving solute-solvent interactions
ΔHsolvent-solvent = enthalpy change involving solvent-solvent interactions 
-Which arrows represent ΔHsolute-solute and ΔHsolvent-solvent?

Accepted Answer

A) arrow (a)and arrow (b) 
B) arrow (a)and arrow (c) 
C) arrow (a)and arrow (d) 
D) arrow (c)and arrow (d)

Question 3

According to the rule of thumb "like dissolves like." ionic solids like NaCl or polar substances like glucose are more soluble in ________ solvents,whereas nonpolar substances like I₂ are more soluble in ________ solvents.

Accepted Answer

The answer of According to the rule of thumb "like...

Question 4

Which of the following pairs of solutions have roughly the same boiling point elevation?

Accepted Answer

A) 0)100 m C6H12O6 and 0.0333 m CuCl2 
B) 0)100 m NaCl and 0.100 m C6H12O6 
C) 0)200 m NaCl and 0.300 m Na2SO4 
D) 0)100 m KCl and 0.0500 m MgBr2

Question 5

When an ionic solute dissolves in water to form an unsaturated solution,the free energy change (ΔGsoln)is

Accepted Answer

A) negative. 
B) zero. 
C) positive. 
D) either A or C,depending on the ionic compound

Question 6

At 80.0°C heptane,C₇H₁₆,has a vapor pressure of 428 mm Hg and octane,C₈H₁₈,has a vapor pressure of 175 mm Hg.What is the vapor pressure of a solution that contains 20.0 g C₇H₁₆ and 11.4 g C₈H₁₈?

Accepted Answer

The answer of At 80.0°C heptane,C₇H₁₆,has a vapor pressure of...

Question 7

Which cation in each set is expected to have the larger (more negative)hydration energy?
I.Mg2+ or Ba2+
II.K+ or Al3+

Accepted Answer

A) Mg2+ in set I and K+ in set II 
B) Mg2+ in set I and Al3+ in set II 
C) Ba2+ in set I and K+ in set II 
D) Ba2+ in set I and Al3+ in set II

Question 8

A solution of LiCl in water has XLiCl = 0.0500.What is the molality?

Accepted Answer

A) 2)60 m LiCl 
B) 2)77 m LiCl 
C) 2)92 m LiCl 
D) 5)26 m LiCl

Question 9

What volume of 3.00 M CH3OH solution is needed to provide 0.220 mol of CH3OH?

Accepted Answer

A) 1)52 mL 
B) 13.6 mL 
C) 73.3 mL 
D) 660 mL

Question 10

What is the weight percent of a caffeine solution made by dissolving 4.35 g of caffeine,C8H10N4O2,in 75 g of benzene,C6H6?

Accepted Answer

A) 0)055% 
B) 0)058% 
C) 5)5% 
D) 5)8%

Question 11

A solution has a density of 1.023 g/mL and a concentration of 0.0800 g/dL.What is the concentration in parts per million?

Accepted Answer

A) 700 ppm 
B) 782 ppm 
C) 800 ppm 
D) 818 ppm

Question 12

A 0.50 m solution of which solute has the largest van't Hoff factor?

Accepted Answer

A) CaCl2 
B) K3PO4 
C) LiCO3 
D) NaNO3

Question 13

The solubility of argon in water at 25°C is 0.0150 mol/L.What is the Henry's Law constant for argon if the partial pressure of argon in air is 0.00934 atm?

Accepted Answer

A) 1)40 × 10-4 mol/(L ∙ atm) 
B) 0)623 mol/(L ∙ atm) 
C) 1)61 mol/(L ∙ atm) 
D) 4)10 mol/(L ∙ atm)

Question 14

For which case would ΔHsoln be expected to be negative?

Accepted Answer

A) if solute-solute interactions are much greater than solvent-solvent and solute-solvent interactions 
B) if solvent-solvent interactions are much greater than solute-solvent and solute-solute interactions 
C) if solute-solvent interactions are much greater than solvent-solvent and solute-solute interactions 
D) if solute-solvent interactions are the same as solvent-solvent and solute-solute interactions

Question 15

When 2.36 g of a nonvolatile solute is dissolved in 100 g of solvent,the largest change in freezing point will be achieved when the solvent is

Accepted Answer

A) benzene,Kf = 5.07. 
B) camphor,Kf = 37.8. 
C) chloroform,Kf = 4.70. 
D) All are expected to have the same freezing point.

Question 16

Arrange the following compounds in order of their expected increasing solubility in water:
KCl,CH3CH2-O-CH2CH3,CH3CH2CH2CH2-OH,CH3CH2CH2CH2CH3.

Accepted Answer

A) CH3CH2CH2CH2CH3 3CH2-O-CH2CH3 3CH2CH2CH2-OH 
B) KCl 3CH2-O-CH2CH3 3CH2CH2CH2-OH 3CH2CH2CH2CH3 
C) CH3CH2CH2CH2CH3 3CH2-O-CH2CH3 3CH2CH2CH2-OH 
D) CH3CH2CH2CH2CH3 3CH2-O-CH2CH3 3CH2CH2CH2-OH < KCl

Question 17

What is the expected freezing point of a 0.50 m solution of Na2SO4 in water? Kf for water is 1.86°C/m.

Accepted Answer

A) -0.93°C 
B) -1.9°C 
C) -2.8°C 
D) -6.5°C

Question 18

How many grams of KBr are required to make 350.mL of a 0.115 M KBr solution?

Accepted Answer

A) 0)338 g 
B) 3)04 g 
C) 4)79 g 
D) 40.3 g

Question 19

A phase diagram of temperature versus composition for a mixture of the two volatile liquids octane (bp = 69°C)and decane (bp = 126°C)is shown. 
-Assume that the vapor at point c is condensed and reboiled.What is the liquid composition of the condensed vapor prior to reboiling?

Accepted Answer

A) 100% decane 
B) composition at point b 
C) composition at point d 
D) composition at point e

Question 20

Calculate the freezing point of a solution of 20.0 g methyl salicylate,C7H6O2,dissolved in 800.g of benzene,C6H6.Kf for benzene is 5.10°C/m and the freezing point is 5.50°C for benzene.

Accepted Answer

A) -1.05°C 
B) 1)05°C 
C) 4)45°C 
D) 6)54°C

Exam 11: Solutions and Their Properties

At a given temperature the vapor pressures of benzene and toluene are 183 mm Hg and 59.2 mm Hg,respectively.Calculate the mole fraction of benzene in the vapor phase over a solution of benzene and toluene with X_benzene = 0.600.

According to the rule of thumb "like dissolves like." ionic solids like NaCl or polar substances like glucose are more soluble in solvents,whereas nonpolar substances like I₂ are more soluble in solvents.

Which of the following pairs of solutions have roughly the same boiling point elevation?

When an ionic solute dissolves in water to form an unsaturated solution,the free energy change (ΔG_soln) is

At 80.0°C heptane,C₇H₁₆,has a vapor pressure of 428 mm Hg and octane,C₈H₁₈,has a vapor pressure of 175 mm Hg.What is the vapor pressure of a solution that contains 20.0 g C₇H₁₆ and 11.4 g C₈H₁₈?

Which cation in each set is expected to have the larger (more negative) hydration energy? I.Mg²⁺ or Ba²⁺ II.K⁺ or Al³⁺

A solution of LiCl in water has X_LiCl = 0.0500.What is the molality?

What volume of 3.00 M CH₃OH solution is needed to provide 0.220 mol of CH₃OH?

What is the weight percent of a caffeine solution made by dissolving 4.35 g of caffeine,C₈H₁₀N₄O₂,in 75 g of benzene,C₆H₆?

A solution has a density of 1.023 g/mL and a concentration of 0.0800 g/dL.What is the concentration in parts per million?

A 0.50 m solution of which solute has the largest van't Hoff factor?

The solubility of argon in water at 25°C is 0.0150 mol/L.What is the Henry's Law constant for argon if the partial pressure of argon in air is 0.00934 atm?

For which case would ΔH_soln be expected to be negative?

When 2.36 g of a nonvolatile solute is dissolved in 100 g of solvent,the largest change in freezing point will be achieved when the solvent is

Arrange the following compounds in order of their expected increasing solubility in water: KCl,CH₃CH₂-O-CH₂CH₃,CH₃CH₂CH₂CH₂-OH,CH₃CH₂CH₂CH₂CH_3.

What is the expected freezing point of a 0.50 m solution of Na₂SO₄ in water? K_f for water is 1.86°C/m.

How many grams of KBr are required to make 350.mL of a 0.115 M KBr solution?

A phase diagram of temperature versus composition for a mixture of the two volatile liquids octane (bp = 69°C) and decane (bp = 126°C) is shown. -Assume that the vapor at point c is condensed and reboiled.What is the liquid composition of the condensed vapor prior to reboiling?

Calculate the freezing point of a solution of 20.0 g methyl salicylate,C₇H₆O₂,dissolved in 800.g of benzene,C₆H₆.K_f for benzene is 5.10°C/m and the freezing point is 5.50°C for benzene.

Exam 11: Solutions and Their Properties

At a given temperature the vapor pressures of benzene and toluene are 183 mm Hg and 59.2 mm Hg,respectively.Calculate the mole fraction of benzene in the vapor phase over a solution of benzene and toluene with Xbenzene = 0.600.

According to the rule of thumb "like dissolves like." ionic solids like NaCl or polar substances like glucose are more soluble in ________ solvents,whereas nonpolar substances like I2 are more soluble in ________ solvents.

Which of the following pairs of solutions have roughly the same boiling point elevation?

When an ionic solute dissolves in water to form an unsaturated solution,the free energy change (ΔGsoln) is

At 80.0°C heptane,C7H16,has a vapor pressure of 428 mm Hg and octane,C8H18,has a vapor pressure of 175 mm Hg.What is the vapor pressure of a solution that contains 20.0 g C7H16 and 11.4 g C8H18?

Which cation in each set is expected to have the larger (more negative) hydration energy? I.Mg2+ or Ba2+ II.K+ or Al3+

A solution of LiCl in water has XLiCl = 0.0500.What is the molality?

What volume of 3.00 M CH3OH solution is needed to provide 0.220 mol of CH3OH?

What is the weight percent of a caffeine solution made by dissolving 4.35 g of caffeine,C8H10N4O2,in 75 g of benzene,C6H6?

A solution has a density of 1.023 g/mL and a concentration of 0.0800 g/dL.What is the concentration in parts per million?

A 0.50 m solution of which solute has the largest van't Hoff factor?

The solubility of argon in water at 25°C is 0.0150 mol/L.What is the Henry's Law constant for argon if the partial pressure of argon in air is 0.00934 atm?

For which case would ΔHsoln be expected to be negative?

When 2.36 g of a nonvolatile solute is dissolved in 100 g of solvent,the largest change in freezing point will be achieved when the solvent is

Arrange the following compounds in order of their expected increasing solubility in water: KCl,CH3CH2-O-CH2CH3,CH3CH2CH2CH2-OH,CH3CH2CH2CH2CH3.

What is the expected freezing point of a 0.50 m solution of Na2SO4 in water? Kf for water is 1.86°C/m.

How many grams of KBr are required to make 350.mL of a 0.115 M KBr solution?

A phase diagram of temperature versus composition for a mixture of the two volatile liquids octane (bp = 69°C) and decane (bp = 126°C) is shown. -Assume that the vapor at point c is condensed and reboiled.What is the liquid composition of the condensed vapor prior to reboiling?

Calculate the freezing point of a solution of 20.0 g methyl salicylate,C7H6O2,dissolved in 800.g of benzene,C6H6.Kf for benzene is 5.10°C/m and the freezing point is 5.50°C for benzene.

At a given temperature the vapor pressures of benzene and toluene are 183 mm Hg and 59.2 mm Hg,respectively.Calculate the mole fraction of benzene in the vapor phase over a solution of benzene and toluene with X_benzene = 0.600.

According to the rule of thumb "like dissolves like." ionic solids like NaCl or polar substances like glucose are more soluble in solvents,whereas nonpolar substances like I₂ are more soluble in solvents.

When an ionic solute dissolves in water to form an unsaturated solution,the free energy change (ΔG_soln) is

At 80.0°C heptane,C₇H₁₆,has a vapor pressure of 428 mm Hg and octane,C₈H₁₈,has a vapor pressure of 175 mm Hg.What is the vapor pressure of a solution that contains 20.0 g C₇H₁₆ and 11.4 g C₈H₁₈?

Which cation in each set is expected to have the larger (more negative) hydration energy? I.Mg²⁺ or Ba²⁺ II.K⁺ or Al³⁺

A solution of LiCl in water has X_LiCl = 0.0500.What is the molality?

What volume of 3.00 M CH₃OH solution is needed to provide 0.220 mol of CH₃OH?

What is the weight percent of a caffeine solution made by dissolving 4.35 g of caffeine,C₈H₁₀N₄O₂,in 75 g of benzene,C₆H₆?

For which case would ΔH_soln be expected to be negative?

Arrange the following compounds in order of their expected increasing solubility in water: KCl,CH₃CH₂-O-CH₂CH₃,CH₃CH₂CH₂CH₂-OH,CH₃CH₂CH₂CH₂CH_3.

What is the expected freezing point of a 0.50 m solution of Na₂SO₄ in water? K_f for water is 1.86°C/m.

Calculate the freezing point of a solution of 20.0 g methyl salicylate,C₇H₆O₂,dissolved in 800.g of benzene,C₆H₆.K_f for benzene is 5.10°C/m and the freezing point is 5.50°C for benzene.