Question 1

A solution of LiCl in water has XLiCl = 0.0800.What is the molality?

Accepted Answer

A) 4.01 m LiCl 
B) 4.44 m LiCl 
C) 4.83 m LiCl 
D) 8.70 m LiCl 
A) 4.01 m LiCl 
B) 4.44 m LiCl 
C) 4.83 m LiCl 
D) 8.70 m LiCl

Question 2

KI does not dissolve well in nonpolar solvents because

Accepted Answer

A) solute-solute interactions are much larger than solvent-solvent or solute-solvent interactions. 
B) solvent-solvent interactions are much larger than solute-solvent or solute-solute interactions. 
C) solute-solvent interactions are much larger than solvent-solvent or solute-solute interactions. 
D) solute-solvent interactions are similar to solvent-solvent and solute-solute interactions. 
A) solute-solute interactions are much larger than solvent-solvent or solute-solvent interactions. 
B) solvent-solvent interactions are much larger than solute-solvent or solute-solute interactions. 
C) solute-solvent interactions are much larger than solvent-solvent or solute-solute interactions. 
D) solute-solvent interactions are similar to solvent-solvent and solute-solute interactions.

Question 3

A solution of a nonelectrolyte solution contains 30.0 g of solute dissolved in 250.0g of water.The freezing point of the water is observed to be -2.50˚C.The Kf for water is 1.86 ˚C/m and normal freezing point of water is 0.00˚C.What is the molar mass of the substance?

Accepted Answer

A) 335 g/mol 
B) 89.5 g/mol 
C) 895 g/mol 
D) 33.5 g/mol 
A) 335 g/mol 
B) 89.5 g/mol 
C) 895 g/mol 
D) 33.5 g/mol

Question 4

Most gases become less soluble in water as the temperature increases.What can be concluded about the signs of ΔHsoln and ΔSsoln in this case?

Accepted Answer

A) ΔHsoln is negative and ΔSsoln is negative. 
B) ΔHsoln is negative and ΔSsoln is positive. 
C) ΔHsoln is positive and ΔSsoln is negative. 
D) ΔHsoln is positive and ΔSsoln is positive. 
A) ΔHsoln is negative and ΔSsoln is negative. 
B) ΔHsoln is negative and ΔSsoln is positive. 
C) ΔHsoln is positive and ΔSsoln is negative. 
D) ΔHsoln is positive and ΔSsoln is positive.

Question 5

To make a 3.00 m solution,one could take 3.00 moles of solute and add

Accepted Answer

A) 1.00 L of solvent. 
B) 1.00 kg of solvent. 
C) enough solvent to make 1.00 L of solution. 
D) enough solvent to make 1.00 kg of solution. 
A) 1.00 L of solvent. 
B) 1.00 kg of solvent. 
C) enough solvent to make 1.00 L of solution. 
D) enough solvent to make 1.00 kg of solution.

Question 6

A solution is prepared by dissolving 171 g of CdCl2 in enough water to make exactly 250.0 mL of solution.If the density of the solution is 1.556 g/mL,what is the weight percent of CdCl2 in the solution?

Accepted Answer

A) 7.17% 
B) 44.0% 
C) 56.0% 
D) 68.4% 
A) 7.17% 
B) 44.0% 
C) 56.0% 
D) 68.4%

Question 7

The boiling point of a solution containing a nonvolatile solute will be ________ than the boiling point of the pure solvent,whereas the boiling point of a solution of two volatile liquids will be ________ than the boiling point of the more volatile liquid and ________ than the boiling point of the less volatile liquid.

Accepted Answer

The answer of The boiling point of a solution containing...

Question 8

Two beakers,one with pure water (light gray)and the other with an aqueous solution of KBr (dark gray),are placed in a closed container represented by drawing (a).Which of the drawings (a)-(d)represents what the beakers will look like after a substantial amount of time has passed?

Accepted Answer

A) drawing (a) 
B) drawing (b) 
C) drawing (c) 
D) drawing (d) 
A) drawing (a) 
B) drawing (b) 
C) drawing (c) 
D) drawing (d)

Question 9

Cocaine,C17H21NO4,in urine can be confirmed by mass spectroscopy at a concentration of 150 ng/mL.Assuming a urine density of 1.025 g/mL,what is this concentration expressed as molality?

Accepted Answer

Question 10

A solution is prepared by dissolving 50.0 g of sucrose,C12H22O11,in 250.g of water at 25°C.What is the vapor pressure of the solution if the vapor pressure of water at 25°C is 23.76 mm Hg?

Accepted Answer

A) 0.247 mm Hg 
B) 19.8 mm Hg 
C) 23.5 mm Hg 
D) 24.0 mm Hg 
A) 0.247 mm Hg 
B) 19.8 mm Hg 
C) 23.5 mm Hg 
D) 24.0 mm Hg

Question 11

Arrange the following compounds in order of their expected increasing solubility in water: NaF,CH3CH2-O-CH2CH3,CH3CH2CH2CH2-OH,CH3CH2CH2CH3.

Accepted Answer

A) CH3CH2CH2CH3  3CH2-O-CH2CH3 3CH2CH2CH2-OH 
B) NaCl 3CH2-O-CH2CH3 3CH2CH2CH2-OH 3CH2CH2CH3   
C) CH3CH2CH2CH3   3CH2-O-CH2CH3 3CH2CH2CH2-OH 
D) CH3CH2CH2CH3  3CH2-O-CH2CH3 3CH2CH2CH2-OH < NaF 
A) CH3CH2CH2CH3  3CH2-O-CH2CH3 3CH2CH2CH2-OH 
B) NaCl 3CH2-O-CH2CH3 3CH2CH2CH2-OH 3CH2CH2CH3   
C) CH3CH2CH2CH3   3CH2-O-CH2CH3 3CH2CH2CH2-OH 
D) CH3CH2CH2CH3  3CH2-O-CH2CH3 3CH2CH2CH2-OH < NaF

Question 12

The coolant in automobiles is often a 50/50 % by volume mixture of ethylene glycol,HOCH2CH2OH,and water.At 20°C,the density of ethylene glycol is 1.1088 g/mL and the density of water is 0.9982 g/mL.Assuming that the volumes are additive,what is the expected freezing point of a 50/50(v/v)% ethylene glycol/water solution? Kf = 1.86°C/m for water.

Accepted Answer

A) -16°C 
B) -17°C 
C) -30°C 
D) -33°C 
A) -16°C 
B) -17°C 
C) -30°C 
D) -33°C

Question 13

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) 1408 ppm 
C) 550 ppm 
D) 818 ppm 
A) 700 ppm 
B) 1408 ppm 
C) 550 ppm 
D) 818 ppm

Question 14

How many grams of sucrose,C12H22O11,must be added to 500.g of water at 100°C to change the vapor pressure to 752 mm Hg?

Accepted Answer

A) 0.295 g 
B) 5.32 g 
C) 10.6 g 
D) 101 g 
A) 0.295 g 
B) 5.32 g 
C) 10.6 g 
D) 101 g

Question 15

At a given temperature the vapor pressures of benzene and toluene are 183 mm Hg and 59.2 mm Hg,respectively.Calculate the total vapor pressure over a solution of benzene and toluene with Xbenzene = 0.400.

Accepted Answer

A) 110 mm Hg 
B) 133 mm Hg 
C) 109 mm Hg 
D) 242 mm Hg 
A) 110 mm Hg 
B) 133 mm Hg 
C) 109 mm Hg 
D) 242 mm Hg

Question 16

Molarity is defined as moles of solute per

Accepted Answer

A) kilogram of solvent. 
B) liter of solution. 
C) mole of solute. 
D) total moles present. 
A) kilogram of solvent. 
B) liter of solution. 
C) mole of solute. 
D) total moles present.

Question 17

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 arrow represents ΔHsolute-solvent?

Accepted Answer

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

Question 18

At a given temperature the vapor pressures of benzene and toluene are 183 mm Hg and 59.2 mm Hg,respectively.Calculate the total vapor pressure over a solution of benzene and toluene with Xbenzene = 0.520.

Accepted Answer

A) 95.2 mm Hg 
B) 121 mm Hg 
C) 124 mm Hg 
D) 242 mm Hg 
A) 95.2 mm Hg 
B) 121 mm Hg 
C) 124 mm Hg 
D) 242 mm Hg

Question 19

To make a 3.0 M solution,one could take 3.00 moles of solute and add

Accepted Answer

A) 1.00 L of solvent. 
B) 1.00 kg of solvent. 
C) enough solvent to make 1.00 L of solution. 
D) enough solvent to make 1.00 kg of solution. 
A) 1.00 L of solvent. 
B) 1.00 kg of solvent. 
C) enough solvent to make 1.00 L of solution. 
D) enough solvent to make 1.00 kg of solution.

Question 20

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

Accepted Answer

A) CaF2 
B) Li3PO4 
C) K2CO3 
D) NaNO3 
A) CaF2 
B) Li3PO4 
C) K2CO3 
D) NaNO3

Exam 12: Solutions and Their Properties

A solution of LiCl in water has XLiCl = 0.0800.What is the molality?

KI does not dissolve well in nonpolar solvents because

A solution of a nonelectrolyte solution contains 30.0 g of solute dissolved in 250.0g of water.The freezing point of the water is observed to be -2.50˚C.The Kf for water is 1.86 ˚C/m and normal freezing point of water is 0.00˚C.What is the molar mass of the substance?

Most gases become less soluble in water as the temperature increases.What can be concluded about the signs of ΔHsoln and ΔSsoln in this case?

To make a 3.00 m solution,one could take 3.00 moles of solute and add

A solution is prepared by dissolving 171 g of CdCl2 in enough water to make exactly 250.0 mL of solution.If the density of the solution is 1.556 g/mL,what is the weight percent of CdCl2 in the solution?

Two beakers,one with pure water (light gray)and the other with an aqueous solution of KBr (dark gray),are placed in a closed container represented by drawing (a).Which of the drawings (a)-(d)represents what the beakers will look like after a substantial amount of time has passed?

Cocaine,C17H21NO4,in urine can be confirmed by mass spectroscopy at a concentration of 150 ng/mL.Assuming a urine density of 1.025 g/mL,what is this concentration expressed as molality?

A solution is prepared by dissolving 50.0 g of sucrose,C12H22O11,in 250.g of water at 25°C.What is the vapor pressure of the solution if the vapor pressure of water at 25°C is 23.76 mm Hg?

Arrange the following compounds in order of their expected increasing solubility in water: NaF,CH3CH2-O-CH2CH3,CH3CH2CH2CH2-OH,CH3CH2CH2CH3.

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?

How many grams of sucrose,C12H22O11,must be added to 500.g of water at 100°C to change the vapor pressure to 752 mm Hg?

At a given temperature the vapor pressures of benzene and toluene are 183 mm Hg and 59.2 mm Hg,respectively.Calculate the total vapor pressure over a solution of benzene and toluene with Xbenzene = 0.400.

Molarity is defined as moles of solute per

At a given temperature the vapor pressures of benzene and toluene are 183 mm Hg and 59.2 mm Hg,respectively.Calculate the total vapor pressure over a solution of benzene and toluene with Xbenzene = 0.520.

To make a 3.0 M solution,one could take 3.00 moles of solute and add

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

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Filters

A solution of LiCl in water has X_LiCl = 0.0800.What is the molality?

A solution of a nonelectrolyte solution contains 30.0 g of solute dissolved in 250.0g of water.The freezing point of the water is observed to be -2.50˚C.The K_f for water is 1.86 ˚C/m and normal freezing point of water is 0.00˚C.What is the molar mass of the substance?

Most gases become less soluble in water as the temperature increases.What can be concluded about the signs of ΔH_soln and ΔS_soln in this case?

A solution is prepared by dissolving 171 g of CdCl₂ in enough water to make exactly 250.0 mL of solution.If the density of the solution is 1.556 g/mL,what is the weight percent of CdCl₂ in the solution?

Cocaine,C₁₇H₂₁NO₄,in urine can be confirmed by mass spectroscopy at a concentration of 150 ng/mL.Assuming a urine density of 1.025 g/mL,what is this concentration expressed as molality?

A solution is prepared by dissolving 50.0 g of sucrose,C₁₂H₂₂O₁₁,in 250.g of water at 25°C.What is the vapor pressure of the solution if the vapor pressure of water at 25°C is 23.76 mm Hg?

Arrange the following compounds in order of their expected increasing solubility in water: NaF,CH₃CH₂-O-CH₂CH₃,CH₃CH₂CH₂CH₂-OH,CH₃CH₂CH₂CH₃.

How many grams of sucrose,C₁₂H₂₂O₁₁,must be added to 500.g of water at 100°C to change the vapor pressure to 752 mm Hg?

At a given temperature the vapor pressures of benzene and toluene are 183 mm Hg and 59.2 mm Hg,respectively.Calculate the total vapor pressure over a solution of benzene and toluene with X_benzene = 0.400.

At a given temperature the vapor pressures of benzene and toluene are 183 mm Hg and 59.2 mm Hg,respectively.Calculate the total vapor pressure over a solution of benzene and toluene with X_benzene = 0.520.