Question 1

A solution is prepared by dissolving 21.0 g of glycerin ( $\mathrm { C } _ { 3 }$ $\mathrm { Hg }$ $\mathrm { O } _ { 3 }$ )in 201 g of ethanol $\left( \mathrm { C } _ { 2 } \mathrm { H } _ { 5 } \mathrm { OH } \right)$ The freezing point of the solution is ________°C.The freezing point of pure ethanol is $- 114.6 ^ { \circ } \mathrm { C }$ .The molal freezing point depression constant ( $K_f$ )for ethanol is $1.99 ^ { \circ } \mathrm { Cm } ^ { - 1 }$ The molar masses of glycerin and of ethanol are 92.1 g mol-1 and 46.1 g mol-1,respectively.

Accepted Answer

A) -112.8 
B) -116.4 
C) 2.26 
D) -112.3 
E) -116.9

Question 2

Determine the Henry's law constant for ammonia in water at 25 °C if an ammonia pressure of 0.022 bar produces a solution with a concentration of 1.3 mol L-1.

Accepted Answer

A) 59 mol L-1 bar-1 
B) 0.017 mol L-1 bar-1 
C) 0.029 mol L-1 bar-1 
D) 35 mol L-1 bar-1 
E) 0.038 mol L-1 bar-1

Question 3

Determine the molality of a solution prepared by dissolving 0.500 moles of CaF2 in 11.5 moles H2O.

Accepted Answer

A) 1.88 mol kg-1 
B) 4.35 mol kg-1 
C) 5.31 mol kg-1 
D) 4.14 mol kg-1 
E) 2.41 mol kg-1

Question 4

What molality of pentane is obtained by dissolving 15 g pentane,C5H12,in 245.0 g hexane,C6H14?

Accepted Answer

A) 0.058 mol kg-1 
B) 0.068 mol kg-1  
C) 0.85 mol kg-1 
D) 61 mol kg-1

Question 5

How does a solution of two volatile components with strong solute-solvent attractions deviate from Raoult's law? Why?

Accepted Answer

The answer of How does a solution of two volatile...

Question 6

The Henry's law constant for helium gas in water at 30 °C is 3.70 × $10 ^ { - 4 }$ mol L-1 bar-1.When the partial pressure of helium above a sample of water is 0.450 bar,the concentration of helium in the water is ________ mol L-1.

Accepted Answer

A) 1.22 × 103 
B) 8.22 × 10-4 
C) 1.67 × 10-4 
D) 0.45 
E) 3.70 × 10-4

Question 7

Identify the major force between ethanol and water.

Accepted Answer

A) dipole-dipole 
B) dispersion 
C) hydrogen bonding 
D) ion-ion 
E) ion-dipole

Question 8

Fluids used for an intravenous transfusion must be ________ with bodily fluids.

Accepted Answer

A) isosmotic 
B) hyperosmotic 
C) hyposmotic 
D) neosmotic 
E) magnosmotic

Question 9

A solution of methanol and water has a vapour pressure of 248 Torr.What would you predict as the mole fractions of each component,assuming ideal behaviour? The vapour pressures of methanol and water are 256 Torr and 55.3 Torr,respectively.

Accepted Answer

A)  $\chi \text { methanol }$ = 0.990,$\chi \text { water }$ = 0.010 
B)  $\chi \text { methanol }$ = 0.940,$\chi \text { water }$ = 0.060 
C)  $\chi \text { methanol }$ = 0.960,$\chi \text { water }$ = 0.040 
D)  $\chi \text { methanol }$ = 0.910,$\chi \text { water }$ = 0.090 
E)  $\chi \text { methanol }$ = 0.900,$\chi \text { water }$ = 0.100

Question 10

Equal masses,5.00 g,of pentane (C5H12)and hexane (C6H14)are mixed.Calculate the vapour pressure of the resulting solution.The vapour pressures of pure pentane and hexane are 425 Torr and 151 Torr,respectively.Assume ideal behaviour.

Accepted Answer

A) 291 Torr 
B) 284 Torr 
C) 317 Torr 
D) 300 Torr 
E) 342 Torr

Question 11

How many moles of KF are contained in 244 mL of 0.135 mol kg-1 KF solution? The density of the solution is 1.22 g mL-1.

Accepted Answer

A) 4.31 × 10-2 mol KF 
B) 4.02 × 10-2 mol KF 
C) 3.29 × 10-2 mol KF 
D) 2.32 × 10-2 mol KF 
E) 1.67 × 10-2 mol KF

Question 12

A solution is 2.25% by weight NaHCO3.How many grams of NaHCO3 are in 150.0 g of solution?

Accepted Answer

A) 1.50 g 
B) 3.38 g 
C) 66.7 g 
D) 225 g

Question 13

Explain why water does not dissolve in gasoline.

Accepted Answer

The answer of Explain why water does not dissolve in...

Question 14

Calculate the volume of solution that has a vapour pressure of 25.8 mbar and contains 200.3 g of galactose,C6H12O6,at a temperature of 22.0 °C.The vapour pressure of pure water at 22 °C is 26.40 mbar,the density of water is 1.00 g mL-1,and assume no change in volume occurs upon dissolution.

Accepted Answer

A) 200 mL 
B) 91.3 mL 
C) 769 mL 
D) 862 mL 
E) 981 mL

Question 15

Commercial grade HCl solutions are typically 39.0% (by mass)HCl in water.Determine the molality of the HCl if the solution has a density of 1.20 g mL-1.

Accepted Answer

A) 39.0 mol kg-1 
B) 17.5 mol kg-1 
C) 6.39 mol kg-1 
D) 10.7 mol kg-1 
E) 9.44 mol kg-1

Question 16

A nonelectrolyte compound with a molar mass of 648 g mol-1 was dissolved in enough water to make 250 mL of solution at 25 °C and produced an osmotic pressure of 27.4 mbar.Calculate the mass of the compound,in g,used to make this solution.

Accepted Answer

A) 0.267 g 
B) 0.179 g 
C) 0.106 g 
D) 0.0873 g 
E) 0.236 g

Question 17

Choose the aqueous solution that has the highest boiling point.These are all solutions of nonvolatile solutes and you should assume ideal van't Hoff factors where applicable.

Accepted Answer

A) 0.100 mol kg-1 NaNO3 
B) 0.100 mol kg-1 Li2SO4 
C) 0.200 mol kg-1 C3H8O3 
D) 0.060 mol kg-1 Na3PO4 
E) They all have the same boiling point.

Question 18

Identify the compound whose solubility decreases with increasing temperature.

Accepted Answer

A) Na2SO4 
B) K2Cr2O7 
C) KNO3 
D) KClO3 
E) NaCl

Question 19

A solution is prepared by dissolving 16.4 g of benzene ( $\mathrm { C } _ { 6 }$ $\mathrm { H } _ { 6 }$ )in 282 g of carbon tetrachloride $\left( \mathrm { CCl } _ { 4 } \right)$ The concentration of benzene in this solution is ________ molal.The molar masses of $\mathrm { C } _ { 6 } \mathrm { H } _ { 6 }$ and $\mathrm { CCl } _ { 4 }$ are $78.1 \mathrm {~g} \mathrm {~mol} ^ { - 1 }$ and $154 \mathrm {~g} \mathrm {~mol} ^ { - 1 }$ respectively.

Accepted Answer

A) 0.704 
B) 5.50 
C) 0.0550 
D) 7.45 × 10-4 
E) 0.745

Question 20

Determine the freezing point depression of a solution that contains 30.7 g glycerin (C3H8O3,molar mass = 92.09 g mol-1)in 376 mL of water.Some possibly useful constants for water are Kf = 1.86 °C m-1 and Kb = 0.512 °C m-1.

Accepted Answer

A) 0.887 °C 
B) 1.65 °C 
C) 2.54 °C 
D) 3.33 °C 
E) 0.654 °C

Exam 12: Solutions

Determine the Henry's law constant for ammonia in water at 25 °C if an ammonia pressure of 0.022 bar produces a solution with a concentration of 1.3 mol L^-1.

Determine the molality of a solution prepared by dissolving 0.500 moles of CaF₂ in 11.5 moles H₂O.

What molality of pentane is obtained by dissolving 15 g pentane,C₅H₁₂,in 245.0 g hexane,C₆H₁₄?

How does a solution of two volatile components with strong solute-solvent attractions deviate from Raoult's law? Why?

The Henry's law constant for helium gas in water at 30 °C is 3.70 × $10 ^ { - 4 }$ mol L^-1 bar^-1.When the partial pressure of helium above a sample of water is 0.450 bar,the concentration of helium in the water is ________ mol L^-1.

Identify the major force between ethanol and water.

Fluids used for an intravenous transfusion must be ________ with bodily fluids.

A solution of methanol and water has a vapour pressure of 248 Torr.What would you predict as the mole fractions of each component,assuming ideal behaviour? The vapour pressures of methanol and water are 256 Torr and 55.3 Torr,respectively.

Equal masses,5.00 g,of pentane (C₅H₁₂) and hexane (C₆H₁₄) are mixed.Calculate the vapour pressure of the resulting solution.The vapour pressures of pure pentane and hexane are 425 Torr and 151 Torr,respectively.Assume ideal behaviour.

How many moles of KF are contained in 244 mL of 0.135 mol kg^-1 KF solution? The density of the solution is 1.22 g mL^-1.

A solution is 2.25% by weight NaHCO₃.How many grams of NaHCO₃ are in 150.0 g of solution?

Explain why water does not dissolve in gasoline.

Commercial grade HCl solutions are typically 39.0% (by mass) HCl in water.Determine the molality of the HCl if the solution has a density of 1.20 g mL^-1.

A nonelectrolyte compound with a molar mass of 648 g mol^-1 was dissolved in enough water to make 250 mL of solution at 25 °C and produced an osmotic pressure of 27.4 mbar.Calculate the mass of the compound,in g,used to make this solution.

Choose the aqueous solution that has the highest boiling point.These are all solutions of nonvolatile solutes and you should assume ideal van't Hoff factors where applicable.

Identify the compound whose solubility decreases with increasing temperature.

Determine the freezing point depression of a solution that contains 30.7 g glycerin (C₃H₈O₃,molar mass = 92.09 g mol^-1) in 376 mL of water.Some possibly useful constants for water are K_f = 1.86 °C m^-1 and K_b = 0.512 °C m^-1.

Exam 12: Solutions

Determine the Henry's law constant for ammonia in water at 25 °C if an ammonia pressure of 0.022 bar produces a solution with a concentration of 1.3 mol L-1.

Determine the molality of a solution prepared by dissolving 0.500 moles of CaF2 in 11.5 moles H2O.

What molality of pentane is obtained by dissolving 15 g pentane,C5H12,in 245.0 g hexane,C6H14?

How does a solution of two volatile components with strong solute-solvent attractions deviate from Raoult's law? Why?

The Henry's law constant for helium gas in water at 30 °C is 3.70 × 10−410 ^ { - 4 }10−4 mol L-1 bar-1.When the partial pressure of helium above a sample of water is 0.450 bar,the concentration of helium in the water is ________ mol L-1.

Identify the major force between ethanol and water.

Fluids used for an intravenous transfusion must be ________ with bodily fluids.

A solution of methanol and water has a vapour pressure of 248 Torr.What would you predict as the mole fractions of each component,assuming ideal behaviour? The vapour pressures of methanol and water are 256 Torr and 55.3 Torr,respectively.

Equal masses,5.00 g,of pentane (C5H12) and hexane (C6H14) are mixed.Calculate the vapour pressure of the resulting solution.The vapour pressures of pure pentane and hexane are 425 Torr and 151 Torr,respectively.Assume ideal behaviour.

How many moles of KF are contained in 244 mL of 0.135 mol kg-1 KF solution? The density of the solution is 1.22 g mL-1.

A solution is 2.25% by weight NaHCO3.How many grams of NaHCO3 are in 150.0 g of solution?

Explain why water does not dissolve in gasoline.

Calculate the volume of solution that has a vapour pressure of 25.8 mbar and contains 200.3 g of galactose,C6H12O6,at a temperature of 22.0 °C.The vapour pressure of pure water at 22 °C is 26.40 mbar,the density of water is 1.00 g mL-1,and assume no change in volume occurs upon dissolution.

Commercial grade HCl solutions are typically 39.0% (by mass) HCl in water.Determine the molality of the HCl if the solution has a density of 1.20 g mL-1.

A nonelectrolyte compound with a molar mass of 648 g mol-1 was dissolved in enough water to make 250 mL of solution at 25 °C and produced an osmotic pressure of 27.4 mbar.Calculate the mass of the compound,in g,used to make this solution.

Choose the aqueous solution that has the highest boiling point.These are all solutions of nonvolatile solutes and you should assume ideal van't Hoff factors where applicable.

Identify the compound whose solubility decreases with increasing temperature.

Determine the freezing point depression of a solution that contains 30.7 g glycerin (C3H8O3,molar mass = 92.09 g mol-1) in 376 mL of water.Some possibly useful constants for water are Kf = 1.86 °C m-1 and Kb = 0.512 °C m-1.

Determine the Henry's law constant for ammonia in water at 25 °C if an ammonia pressure of 0.022 bar produces a solution with a concentration of 1.3 mol L^-1.

Determine the molality of a solution prepared by dissolving 0.500 moles of CaF₂ in 11.5 moles H₂O.

What molality of pentane is obtained by dissolving 15 g pentane,C₅H₁₂,in 245.0 g hexane,C₆H₁₄?

The Henry's law constant for helium gas in water at 30 °C is 3.70 × $10 ^ { - 4 }$ mol L^-1 bar^-1.When the partial pressure of helium above a sample of water is 0.450 bar,the concentration of helium in the water is ________ mol L^-1.

Equal masses,5.00 g,of pentane (C₅H₁₂) and hexane (C₆H₁₄) are mixed.Calculate the vapour pressure of the resulting solution.The vapour pressures of pure pentane and hexane are 425 Torr and 151 Torr,respectively.Assume ideal behaviour.

How many moles of KF are contained in 244 mL of 0.135 mol kg^-1 KF solution? The density of the solution is 1.22 g mL^-1.

A solution is 2.25% by weight NaHCO₃.How many grams of NaHCO₃ are in 150.0 g of solution?

Commercial grade HCl solutions are typically 39.0% (by mass) HCl in water.Determine the molality of the HCl if the solution has a density of 1.20 g mL^-1.

A nonelectrolyte compound with a molar mass of 648 g mol^-1 was dissolved in enough water to make 250 mL of solution at 25 °C and produced an osmotic pressure of 27.4 mbar.Calculate the mass of the compound,in g,used to make this solution.

Determine the freezing point depression of a solution that contains 30.7 g glycerin (C₃H₈O₃,molar mass = 92.09 g mol^-1) in 376 mL of water.Some possibly useful constants for water are K_f = 1.86 °C m^-1 and K_b = 0.512 °C m^-1.