Deck 11: Solutions and Their Properties

Question 1

Which of the following mixtures have components which can be separated by filtration?

A)colloids
B)solutions
C)suspensions
D)All of these

Answer 1

suspensions

Question 2

When two similar liquids mix to form a solution,the entropy of solution (ΔS_soln)is expected to be

A)negative.
B)zero.
C)positive.
D)negative at low temperatures but positive at high temperatures.

Answer 2

positive.

Question 3

Commercial cold packs often contain solid NH₄NO₃ and a pouch of water.The temperature of the pack drops as the NH₄NO₃ dissolves in water.Therefore,for the dissolving of NH₄NO₃ in water,

A)ΔH_soln is negative and ΔS_soln may be negative or positive.
B)ΔH_soln is negative and Δ_Ssoln is positive.
C)ΔH_soln is positive and ΔS_soln may be negative or positive.
D)ΔH_soln is positive and ΔS_soln is positive.

Answer 3

ΔH_soln is positive and ΔS_soln is positive.

Question 4

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

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 5

Which is not a solution?

A)brass
B)fog
C)hydrochloric acid
D)wine

Question 6

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

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

Question 7

Which cation in each set would be expected to have the larger (more negative)hydration energy?
I.Fe²⁺ or Fe³⁺
II.Li⁺ or NH₄⁺

A)Fe²⁺ in set I and Li⁺ in set II
B)Fe²⁺ in set I and NH₄⁺ in set II
C)Fe³⁺ in set I and Li⁺ in set II
D)Fe³⁺ in set I and NH₄⁺ in set II

Question 8

KBr does not dissolve well in nonpolar solvents because

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 9

In the process of dissolving ionic compounds,the cations and anions are separated from the crystal lattice and surrounded by an ordered shell of solvent molecules.If the solvent is water,the dissolved ions are said to be

A)halogenated.
B)homogenized.
C)hybridized.
D)hydrated.

Question 10

For a liquid solution made by dissolving a solid or a gas in a liquid,the

A)liquid is the solute.
B)liquid is the solvent.
C)solute is the component present in the greatest amount.
D)solvent is the component present in the greatest amount.

Question 11

The change in the Gibbs free energy for dissolving more solute in a supersaturated solution is

A)negative.
B)zero.
C)positive.
D)positive at low temperatures and negative at high temperatures.

Question 12

Although there are exceptions,which is most likely to be true for the dissolving of a solid in a liquid?

A)ΔH_soln is positive.
B)ΔH_soln is negative.
C)ΔS_soln is positive.
D)ΔS_soln is negative.

Question 13

One reason ionic compounds do not dissolve well in nonpolar solvents is that

A)ion-dipole interactions are too large for effective solvation to occur.
B)ion-solvent interactions are not strong enough to solvate the ions in solution.
C)not all cations and anions have the same magnitude of charge and therefore do not form neutral ion pairs.
D)there are no forces of attraction between ions and nonpolar molecules.

Question 14

When a particular solid begins to dissolve in water,the temperature rises dramatically.For the dissolving of this solid in pure water

A)ΔH_soln is always negative and ΔS_soln may be negative or positive.
B)ΔH_soln is always negative and ΔS_soln is always positive.
C)ΔH_soln is always positive and ΔS_soln may be negative or positive.
D)ΔH_soln is always positive and ΔS_soln is always positive.

Question 15

In most liquid solutions,the component present in the larger amount is called the

A)dispersed medium.
B)emulsifying agent.
C)solute.
D)solvent.

Question 16

For which case would ΔH_soln be expected to be negative?

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 17

Stainless steel is an example of a ________ solution.

A)gas/solid
B)liquid/liquid
C)solid/liquid
D)solid/solid

Question 18

The change in the Gibbs free energy for dissolving solute in a saturated solution is

A)negative.
B)zero.
C)positive.
D)positive at low temperatures and negative at high temperatures.

Question 19

The rubbing alcohol sold in drug stores often is composed of 70% isopropyl alcohol and 30% water.In this solution

A)isopropyl alcohol is the solvent.
B)water is the solvent.
C)both water and isopropyl alcohol are solvents.
D)neither water nor isopropyl alcohol is a solvent.

Question 20

Iodine,I₂(s),is more soluble in dichloromethane,CH₂Cl₂(l),than in water because

A)both iodine and dichloromethane have strong ion-dipole interactions.
B)the dipole-dipole forces in dichloromethane are much stronger than the dispersion forces in iodine.
C)the intermolecular forces are similar in both iodine and dichloromethane.
D)iodine is polar and dichloromethane has a large number of hydrogen bonds.

Question 21

Formaldehyde is a carcinogenic volatile organic compound with a permissible exposure level of 0.75 ppm.At this level,how many grams of formaldehyde are permissible in a 6.0-L breath of air having a density of 1.2 kg/m³?

A)3)8 × 10^-2 g formaldehyde
B)5)4 × 10^-6 g formaldehyde
C)3)8 g formaldehyde
D)5)4 g formaldehyde

Question 22

The dose of amoxicillin given to a young child is 40 mg/kg of body weight/day.If the amoxicillin is administered as a suspension having a concentration of 400 mg/5 mL,how many mL of amoxicillin must be administered per dose for a child weighing 18 pounds?

A)2)0 mL
B)4)1 mL
C)4)5 mL
D)9)9 mL

Question 23

Substances with high lattice energies tend to be less soluble than substances with low lattice energies.On that basis predict the relative aqueous solubility at 20°C,from highest to lowest,of the following ionic compounds: Ce₂(SO₄)₃,K₂SO₄,KBr,NaCl.

A)Ce₂(SO₄)₃ > K₂SO₄ > KBr > NaCl
B)Ce₂(SO₄)₃ > K₂SO₄ > NaCl > KBr
C)KBr > NaCl > K₂SO₄ > Ce₂(SO₄)₃
D)NaCl > KBr > K₂SO₄ > Ce₂(SO₄)₃

Question 24

What are the major solute-solvent interactions created when KBr dissolves in water?

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

Question 25

For the process of dissolving a solid in a liquid,which of the following statements is true?

A)ΔH_soln is always negative and ΔS_soln is usually positive.
B)ΔH_soln is always positive and ΔS_soln is usually negative.
C)ΔH_soln is either positive or negative and ΔS_soln is usually positive.
D)ΔH_soln is either positive or negative and ΔS_soln is usually negative.

Question 26

Which concentration becomes smaller as the temperature is increased from 20°C to 80°C?

A)mass %
B)molality
C)molarity
D)mole fraction

Question 27

What are the major solute-solvent interactions created when HOCH₂CH₂OH dissolves in water?

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

Question 28

What is the mole fraction of ethanol in a solution made by dissolving 14.6 g of ethanol,C₂H₅OH,in 53.6 g of water?

A)0)0964
B)0)106
C)0)214
D)0)272

Question 29

A solution is prepared by dissolving 17.75 g sulfuric acid,H₂SO₄,in enough water to make 100.0 mL of solution.If the density of the solution is 1.1094 g/mL,what is the mole fraction H₂SO₄ in the solution?

A)0)0181
B)0)0338
C)0)0350
D)19.0

Question 30

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)ΔH_soln is negative and ΔS_soln is negative.
B)ΔH_soln is negative and ΔS_soln is positive.
C)ΔH_soln is positive and ΔS_soln is negative.
D)ΔH_soln is positive and ΔS_soln is positive.

Question 31

What is the molality of ethanol in a solution made by dissolving 14.6 g of ethanol,C₂H₅OH,in 53.6 g of water?

A)0)00591 m
B)0)272 m
C)5)91 m
D)272 m

Question 32

What is the mole fraction of I₂ in a solution made by dissolving 27.8 g of I₂ in 245 g of hexane,C₆H₁₄?

A)0)0371
B)0)0385
C)0)0715
D)0)0770

Question 33

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

Question 34

Molarity is defined as moles of solute per

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

Question 35

Fresh air contains approximately 400 ppm CO₂,whereas the breath of an intoxicated person contains about 4 percent CO₂.The amount of CO₂ in the breath of an intoxicated person is ________ times the amount of CO₂ in fresh air.

A)10^-2
B)10^-1
C)10¹
D)10²

Question 36

Molality is defined as moles of solute per

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

Question 37

Which should be least soluble in water?

A)
B)
C)
D)

Question 38

Which of the following should most favor the solubility of an ionic solid in water?

A)a low lattice energy for the solid and a low hydration energy for its ions
B)a low lattice energy for the solid and a high hydration energy for its ions
C)a high lattice energy for the solid and a low hydration energy for its ions
D)a high lattice energy for the solid and a high hydration energy for its ions

Question 39

What is the mole fraction of oxygen in a gas mixture that is 22% oxygen and 78% nitrogen by volume?

A)0)20
B)0)22
C)0)25
D)0)28

Question 40

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

A)CH₃CH₂CH₂CH₂CH₃ < KCl < CH₃CH₂-O-CH₂CH₃ < CH₃CH₂CH₂CH₂-OH
B)KCl < CH₃CH₂-O-CH₂CH₃ < CH₃CH₂CH₂CH₂-OH < CH₃CH₂CH₂CH₂CH₃
C)CH₃CH₂CH₂CH₂CH₃ < CH₃CH₂-O-CH₂CH₃ < KCl < CH₃CH₂CH₂CH₂-OH
D)CH₃CH₂CH₂CH₂CH₃ < CH₃CH₂-O-CH₂CH₃ < CH₃CH₂CH₂CH₂-OH < KCl

Question 41

To make a 2.00 m solution,one could take 2.00 moles of solute and add

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 42

To make a 2.0 M solution,one could take 2.00 moles of solute and add

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 43

Aqueous solutions of 30% (by weight)hydrogen peroxide,H₂O₂,are used to oxidize metals or organic molecules in chemical reactions.Given that the density of the solution is 1.11 g/mL,calculate the molarity.

A)0)794 M
B)6)78 M
C)9)79 M
D)12.6 M

Question 44

What molality of pentane is obtained by dissolving 5.0 g pentane,C₅H₁₂,in 245.0 g hexane,C₆H₁₄?

A)0)020 m
B)0)024 m
C)0)28 m
D)20.m

Question 45

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?

A)7)17%
B)44.0%
C)56.0%
D)68.4%

Question 46

A solution is prepared by dissolving 17.75 g sulfuric acid,H₂SO₄,in enough water to make exactly 100.0 mL of solution.If the density of the solution is 1.1094 g/mL,what is the weight % H₂SO₄ in the solution?

A)16.00%
B)18.00%
C)19.00%
D)84.00%

Question 47

Sodium hydroxide is available commercially as a 50.0% by weight aqueous solution.Calculate the molality of this sodium hydroxide solution.

A)0)450 m
B)19.1 m
C)25.0 m
D)125.m

Question 48

How much water must be added to 42.0 g of CaCl₂ to produce a solution that is 35.0 wt% CaCl₂?

A)56.7 g
B)78.0 g
C)83.3 g
D)120 g

Question 49

Aqueous solutions of 30.0% (by weight)hydrogen peroxide,H₂O₂,are used to oxidize metals or organic molecules in chemical reactions.Calculate the molality of this solution.

A)0)974 m
B)6)78 m
C)9)79 m
D)12.6 m

Question 50

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

A)0)440 M
B)0)684 M
C)0)933 M
D)3)73 M

Question 51

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

Question 52

What is the weight percent of vitamin C in a solution made by dissolving 1.30 g of vitamin C,C₆H₈O₆,in 55.0 g of water?

A)0)195%
B)0)242%
C)2)31%
D)2)36%

Question 53

Sodium hydroxide is available commercially as a 50.0% by weight aqueous solution.The density of the solution is 1.53 g/mL.Calculate the molarity of this sodium hydroxide solution.

A)0)450 M
B)19.1 M
C)25.0 M
D)125.M

Question 54

How many grams of KBr are required to make 650.mL of a 0.115 M KBr solution?

A)0)628 g
B)5)65 g
C)8)90 g
D)74.8 g

Question 55

What volume of 3.00 M CH₃OH solution is needed to provide 0.270 mol of CH₃OH?

A)1)23 mL
B)11.1 mL
C)90.0 mL
D)810 mL

Question 56

What is the molality of a glucose solution prepared by dissolving 18.0 g of glucose,C₆H₁₂O₆,in 125.9 g of water?

A)7)94 × 10^-4 m
B)0)143 m
C)0)695 m
D)0)794 m

Question 57

A solution is prepared by dissolving 17.75 g sulfuric acid,H₂SO₄,in enough water to make 100.0 mL of solution.If the density of the solution is 1.1094 g/mL,what is the molality?

A)0)1775 m H₂SO₄
B)0)1810 m H₂SO₄
C)1)810 m H₂SO₄
D)1)940 m H₂SO₄

Question 58

What volume of 0.716 M KBr solution is needed to provide 10.5 g of KBr?

A)7)52 mL
B)14.7 mL
C)63.2 mL
D)123 mL

Question 59

A solution is 2.25% by weight NaHCO₃.How many grams of NaHCO₃ are in 450.0 g of solution?

A)0)500 g
B)10.1 g
C)200 g
D)225 g

Question 60

A solution is prepared by dissolving 17.75 g sulfuric acid,H₂SO₄,in enough water to make 100.0 mL of solution.If the density of the solution is 1.1094 g/mL,what is the molarity?

A)0)1775 M H₂SO₄
B)0)1810 M H₂SO₄
C)1)810 M H₂SO₄
D)1)940 M H₂SO₄

Question 61

Which of the following does not affect the solubility of a solute in a given solvent?

A)polarity of the solute
B)polarity of the solvent
C)rate of stirring
D)temperature of the solvent and solute

Question 62

At 25.0°C,a solution has a concentration of 3.179 M and a density of 1.260 g/mL.The density of the solution at 50.0°C is 1.249 g/mL.What is the molarity of the solution at 50.0°C?

A)2)545 M
B)3)151 M
C)3)179 M
D)3)230 M

Question 63

A solution is prepared by dissolving 40.0 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?

A)0)198 mm Hg
B)20.5 mm Hg
C)23.6 mm Hg
D)24.0 mm Hg

Question 64

A 1.30 M solution of CaCl₂ in water has a density of 1.11 g/mL.What is the molality?

A)1)17 m CaCl₂
B)1)25 m CaCl₂
C)1)35 m CaCl₂
D)1)44 m CaCl₂

Question 65

The Henry's Law constant of methyl bromide,CH₃Br,is k = 0.159 mol/(L ∙ atm)at 25°C.What is the solubility of methyl bromide in water at 25°C and at a partial pressure of 250.mm Hg?

A)0)0523 mol/L
B)0)329 mol/L
C)0)483 mol/L
D)39.8 mol/L

Question 66

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

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

Question 67

In which case should CO₂(g)be more soluble in water?

A)The total pressure is 5 atm and the partial pressure of CO₂ is 1 atm.
B)The total pressure is 3 atm and the partial pressure of CO₂ is 2 atm.
C)The total pressure is 1 atm and the partial pressure of CO₂ is 0.03 atm.
D)The total pressure is 1 atm and the partial pressure of CO₂ is 0.5 atm.

Question 68

In general,as the temperature increases,the solubility of gases in water ________ and the solubility of most solids in water ________.

A)decreases,decreases
B)decreases,increases
C)increases,decreases
D)increases,increases

Question 69

A saturated solution is defined as

A)a concentrated solution.
B)a solution that is in equilibrium with pure solvent.
C)a solution than is in equilibrium with undissolved solute.
D)a solution that is in equilibrium with both pure solvent and undissolved solute.

Question 70

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 = 0.600.

A)110 mm Hg
B)121 mm Hg
C)133 mm Hg
D)242 mm Hg

Question 71

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.

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

Question 72

A solution of LiCl in water is 18.0 wt% LiCl.What is the mole fraction of LiCl?

A)0)0853
B)0)0933
C)0)425
D)4)56

Question 73

A 3.17 m solution of CaCl₂ in water has a density of 1.24 g/mL.What is the molarity?

A)2)56 M CaCl₂
B)2)91 M CaCl₂
C)3)50 M CaCl₂
D)3)93 M CaCl₂

Question 74

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?

A)0)295 g
B)5)32 g
C)10.6 g
D)101 g

Question 75

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?

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 76

Which of the following is not an application of colligative properties?

A)adding silver to mercury to lower the vapor pressure of mercury
B)desalinating sea water by reverse osmosis
C)melting snow by application of salt
D)reduced boiling points of pure liquids at increased altitudes

Question 77

Which of the following statements is true for a supersaturated solution?

A)The solute in the solution is at equilibrium with undissolved solute.
B)The solution contains more than the equilibrium amount of solute.
C)The solution is stable and the solute will not precipitate.
D)A supersaturated solution is more than 50% solute by mass.

Question 78

The solubility of gaseous solutes in liquid solvents is greater when the

A)external pressure over the solution is increased.
B)external pressure is decreased.
C)partial pressure of the gas above the solution is increased.
D)partial pressure of the solvent is increased.

Question 79

A KCl solution is prepared by dissolving 40.0 g KCl in 250.0 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?

A)20.5 mm Hg
B)22.1 mm Hg
C)22.9 mm Hg
D)25.5 mm Hg

Question 80

A 2.00 M solution of CaCl₂ in water has a density of 1.17 g/mL.What is the mole fraction of CaCl₂?

A)0)0348
B)0)0360
C)0)0366
D)0)0380