Deck 12: Solutions

Question 1

Which of the following statements is true?

A)The solubility of a gas in water increases with increasing pressure.
B)The solubility of a gas in water decreases with increasing pressure.
C)The solubility of a gas in water increases with decreasing pressure.
D)The solubility of a gas in water decreases with decreasing pressure.
E)None of the above statements are true.

Answer 1

The solubility of a gas in water increases with increasing pressure.

Question 2

Which of the following ions should have the most exothermic ΔH_hydration?

A)Na^⁺
B)Mg^2⁺
C)Al^3⁺
D)Ca^2⁺
E)Sr^2⁺

Answer 2

Al^3⁺

Question 3

Which of the following compounds will be most soluble in ethanol (CH₃CH₂OH)?

A)trimethylamine (N(CH₃)₃)
B)acetone (CH₃COCH₃)
C)ethylene glycol (HOCH₂CH₂OH)
D)hexane (CH₃CH₂CH₂CH₂CH₂CH₃)
E)None of these compounds should be soluble in methanol.

Answer 3

ethylene glycol (HOCH₂CH₂OH)

Question 4

Give the term for amount of solute in mole per mass of solvent in kg.

A)molality
B)molarity
C)mole fraction
D)mole percent
E)mass percent

Question 5

A solution is formed at room temperature by vigorously dissolving enough of the solid solute so that some solid remains at the bottom of the solution.Which statement below is true?

A)The solution is considered unsaturated.
B)The solution is considered supersaturated.
C)The solution is considered saturated.
D)The solution would be considered unsaturated if it were cooled a bit to increase the solubility of the solid.
E)None of the above are true.

Question 6

Choose the situation below that would result in a ΔH_solution near 0.

A)When
>>

B)When
>

C)When
<

D)When
Is close to

E)There isn't enough information to determine.

Question 7

Determine the solubility of CO₂ in soda water at 25°C if the pressure of CO₂ is 5.2 atm.The Henry's law constant for carbon dioxide in water at this temperature is 3.4 × 10^-2 M/atm.

A)0.15 M
B)0.57 M
C)0.65 M
D)0.18 M
E)0.29 M

Question 8

Identify the gas that is dissolved in carbonated sodas.

A)carbon dioxide
B)oxygen
C)nitrogen
D)carbon monoxide
E)hydrogen

Question 9

Determine the solubility of N₂ in water exposed to air at 25°C if the atmospheric pressure is 1.2 atm.Assume that the mole fraction of nitrogen is 0.78 in air and the Henry's law constant for nitrogen in water at this temperature is 6.1 × 10^-4 M/atm.

A)1.5 × 10^-4 M
B)6.5 × 10^-4 M
C)5.7 × 10^-4 M
D)1.8 × 10^-4 M
E)3.6 × 10^-4 M

Question 10

Which of the following statements is true?

A)The solubility of a solid is not dependent on either temperature or pressure.
B)The solubility of a solid is highly dependent on pressure.
C)The solubility of a solid is highly dependent on both pressure and temperature.
D)The solubility of a solid is highly dependent on temperature.
E)None of the above.

Question 11

A solution containing less than the equilibrium amount of solvent is called ________.

A)an unsaturated solution
B)a solute
C)a supersaturated solution
D)a saturated solution.
E)a solvent

Question 12

Choose the situation below that would result in an endothermic ΔH_solution.

A)When >
B)When <
C)When Is close to
D)When >>
E)There isn't enough information to determine.

Question 13

Give the intermolecular force that is responsible for the solubility of ethanol in water.

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

Question 14

Which of the following compounds is most soluble in hexane (CH₃CH₂CH₂CH₂CH₂CH₂CH₃)?

A)methanol
B)ethanol
C)1-propanol
D)1-butanol
E)1-pentanol

Question 15

Determine DH_lattice for KBr if the ΔH_solution (KBr)= +19.9 kJ/mol and the
ΔH_hydration (KBr)= -670.kJ/mol.

A)+650 kJ/mol
B)-650 kJ/mol
C)+690 kJ/mol
D)-710 kJ/mol
E)-690 kJ/mol

Question 16

Choose the situation below that would result in an exothermic ΔH_solution.

A)When >
B)When Is close to
C)When <
D)When >>
E)There isn't enough information to determine.

Question 17

Which of the following compounds will be most soluble in pentane (C₅H₁₂)?

A)pentanol (CH₃CH₂CH₂CH₂CH₂OH)
B)benzene (C₆H₆)
C)acetic acid (CH₃CO₂H)
D)ethyl methyl ketone (CH₃CH₂COCH₃)
E)None of these compounds should be soluble in pentane.

Question 18

Which of the following statements is true?

A)In general,the solubility of a solid in water decreases with increasing temperature.
B)In general,the solubility of a gas in water decreases with increasing temperature.
C)The solubility of a gas in water usually increases with decreasing pressure.
D)The solubility of an ionic solid in water decreases with increasing temperature.
E)None of the above statements are true.

Question 19

Which of the following should have the largest Henry's law constant (k_H)in water?

A)Ar
B)CO
C)Xe
D)CH₃CH₃
E)CO₂

Question 20

Choose the statement below that is true.

A)A solution will form between two substances if the solute-solvent interactions are of comparable strength to the solute-solute and solvent-solvent interactions.
B)A solution will form between two substances if the solute-solvent interactions are small enough to be overcome by the solute-solute and solvent-solvent interactions.
C)A solution will form between two substances if the solute-solute interactions are strong enough to overcome the solvent-solvent interactions.
D)A solution will form between two substances only if the solvent-solvent interactions are weak enough to overcome the solute-solvent interactions.
E)None of the above are true.

Question 21

What mass (in g)of NH₃ must be dissolved in 475 g of methanol to make a 0.250 m solution?

A)2.02 g
B)4.94 g
C)1.19 g
D)8.42 g
E)1.90 g

Question 22

What mass of ethane (CH₃CH₃)is contained in 50.0 mL of a 13.9% by mass solution of ethane in hexane? The density of the solution is 0.611 g/mL.

A)2.35 g
B)8.49 g
C)11.8 g
D)6.95 g
E)4.25 g

Question 23

How many moles of KF are contained in 347 g of water in a 0.175 m KF solution?

A)1.65 × 10^-2 mol KF
B)5.04 × 10^-2 mol KF
C)6.07 × 10^-2 mol KF
D)3.22 × 10^-2 mol KF
E)1.98 × 10^-2 mol KF

Question 24

Which of the following concentration units are temperature dependent?

A)mole fraction
B)molality
C)mass percent
D)molarity
E)none of the above

Question 25

A solution is prepared by dissolving 76.3 g NaI in 545 g of water.Determine the mole fraction of NaI if the final volume of the solution is 576 mL.

A)6.04 × 10^-3
B)1.65 × 10^-2
C)1.40 × 10^-3
D)1.32 × 10^-2
E)8.84 × 10^-2

Question 26

Determine the Henry's law constant for ammonia in water at 25°C if an ammonia pressure of
0.022 atm produces a solution with a concentration of 1.3 M.

A)59 M/atm
B)0.017 M/atm
C)0.029 M/atm
D)35 M/atm
E)0.038 M/atm

Question 27

Calculate the mole fraction of total ions in an aqueous solution prepared by dissolving 0.400 moles of MgCl₂ in 850.0 g of water.

A)0.00841
B)0.0254
C)0.00848
D)0.0248
E)0.0167

Question 28

A solution is prepared by dissolving 98.6 g of NaCl in enough water to form 875 mL of solution.Calculate the mass % of the solution if the density of the solution is 1.06 g/mL.

A)11.3%
B)12.7%
C)9.4%
D)10.6%
E)11.9%

Question 29

How many moles of KF are contained in 244 mL of 0.135 m KF solution? The density of the solution is 1.22 g/mL.

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 30

A solution is prepared by dissolving 38.6 g sucrose (C₁₂H₂₂O₁₁)in 495 g of water.Determine the mole fraction of sucrose if the final volume of the solution is 508 mL.

A)4.09 × 10^-3
B)7.80 × 10^-2
C)1.28 × 10^-3
D)7.23 × 10^-2
E)2.45 × 10^-3

Question 31

Determine the partial pressure of oxygen necessary to form an aqueous solution that is 4.1 × 10^-4 M O₂ at 25°C.The Henry's law constant for oxygen in water at 25°C is 1.3 × 10^-3 M/atm.

A)1.9 atm
B)0.53 atm
C)0.24 atm
D)0.77 atm
E)0.32 atm

Question 32

A 1.00 L sample of water contains 0.0036 g of Cl^⁻ ions.Determine the concentration of chloride ions in ppm if the density of the solution is 1.00 g/mL.

A)2.8 ppm
B)7.2 ppm
C)3.6 ppm
D)1.8 ppm
E)5.4 ppm

Question 33

Identify the colligative property.

A)vapor pressure lowering
B)freezing point depression
C)boiling point elevation
D)osmotic pressure
E)all of the above

Question 34

What mass of CuCl₂ is contained in 75.85 g of a 22.4% by mass solution of CuCl₂ in water.

A)17.0 g
B)5.89 g
C)29.5 g
D)33.9 g
E)11.2 g

Question 35

Calculate the molality of a solution that is prepared by mixing 25.5 mL of CH₃OH (d = 0.792 g/mL)and 387 mL of CH₃CH₂CH₂OH (d = 0.811 g/mL).

A)0.630 m
B)0.812 m
C)1.57 m
D)1.89 m
E)4.98 m

Question 36

Calculate the molality of a solution formed by dissolving 27.8 g of LiI in 500.0 mL of water.

A)0.254 m
B)0.394 m
C)0.556 m
D)0.241 m
E)0.415 m

Question 37

A 4.55 L sample of water contains 0.115 g of sodium ions.Determine the concentration of sodium ions in ppm if the density of the solution is 1.00 g/mL.

A)52.3 ppm
B)13.2 ppm
C)12.7 ppm
D)25.3 ppm
E)36.5 ppm

Question 38

A solution is prepared by dissolving 49.3 g of KBr in enough water to form 473 mL of solution.Calculate the mass % of KBr in the solution if the density is 1.12 g/mL.

A)10.4%
B)8.57%
C)10.1%
D)11.7%
E)9.31%

Question 39

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

A)1.88 m
B)4.35 m
C)5.31 m
D)4.14 m
E)2.41 m

Question 40

Calculate the mass of oxygen (in mg)dissolved in a 5.00 L bucket of water exposed to a pressure of 1.13 atm of air.Assume the mole fraction of oxygen in air to be 0.21 and the Henry's law constant for oxygen in water at this temperature to be 1.3 × 10^-3 M/atm.

A)49.4 mg
B)23.5 mg
C)9.87 mg
D)27.3 mg
E)13.7 mg

Question 41

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

A)7.79 M
B)10.7 M
C)12.8 M
D)9.35 M
E)13.9 M

Question 42

Place the following solutions in order of increasing osmotic pressure.
I.0.15 M C₂H₆O₂
II.0.15 M MgCl₂
III.0.15 M NaCl

A)III < I < II
B)II < III < I
C)I < II < III
D)II < I < III
E)I < III < II

Question 43

Give the reason that antifreeze is added to a car radiator.

A)The freezing point is lowered and the boiling point is elevated.
B)The freezing point is elevated and the boiling point is lowered.
C)The freezing point and the boiling point are elevated.
D)The freezing point and the boiling point are lowered.
E)None of the above

Question 44

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.

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

Question 45

The boiling point elevation of an aqueous sucrose solution is found to be 0.39°C.What mass of sucrose (molar mass = 342.30 g/mol)would be needed to dissolve in 500.0 g of water?
K_b (water)= 0.512°C/m.

A)261 g sucrose
B)528 g sucrose
C)762 g sucrose
D)223 g sucrose
E)130.g sucrose

Question 46

Determine the molality of an aqueous solution prepared by dissolving 0.112 moles of LiCl in 13.7 moles of H₂O.

A)0.454 m
B)0.220 m
C)0.818 m
D)0.122 m
E)0.153 m

Question 47

Calculate the boiling point of a solution of 500.0 g of ethylene glycol (C₂H₆O₂)dissolved in 500.0 g of water.K_f = 1.86°C/m and K_b = 0.512°C/m.Use 100°C as the boiling point of water.

A)108°C
B)92°C
C)130°C
D)70°C
E)8.3°C

Question 48

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

A)0.887°C
B)1.65°C
C)3.33°C
D)4.95°C
E)0.654°C

Question 49

A solution is 0.0433 m LiF.What is the molarity of the solution if the density is 1.10 g/mL?

A)0.0441 M
B)0.0390 M
C)0.0519 M
D)0.0476 M
E)0.0417 M

Question 50

Calculate the freezing point of a solution of 500.0 g of ethylene glycol (C₂H₆O₂)dissolved in 500.0 g of water.K_f = 1.86°C/m and K_b = 0.512°C/m.

A)30.0°C
B)-30.0°C
C)8.32°C
D)-8.32°C
E)70.2°C

Question 51

Determine the vapor pressure of a solution at 25°C that contains 76.6 g of glucose (C₆H₁₂O₆)in 250.0 mL of water.The vapor pressure of pure water at 25°C is 23.8 torr.

A)70.8 torr
B)72.9 torr
C)23.1 torr
D)22.9 torr
E)7.29 torr

Question 52

An aqueous solution is 0.387 M in HCl.What is the molality of the solution if the density is 1.23 g/mL?

A)0.115 m
B)0.387 m
C)0.315 m
D)0.411 m
E)0.318 m

Question 53

Choose the aqueous solution with the lowest vapor pressure.These are all solutions of nonvolatile solutes and you should assume ideal van't Hoff factors where applicable.

A)0.120 m C₂H₆O₂
B)0.040 m (NH₄)₂SO₄
C)0.060 m K₂CO₃
D)0.030 m LiC₂H₃O₂
E)They all have the same vapor pressure.

Question 54

Choose the aqueous solution with the highest vapor pressure.These are all solutions of nonvolatile solutes and you should assume ideal van't Hoff factors where applicable.

A)0.50 m C₃H₈O₃
B)0.50 m C₂H₆O₂
C)0.50 m C₆H₁₂O6
D)0.50 m C₁₂H₂₂O₁₁
E)They all have about the same vapor pressure.

Question 55

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.

A)0.100 m AlCl₃
B)0.100 m NaCl
C)0.100 m MgCl₂
D)0.100 m C₆H₁₂O₆
E)They all have the same boiling point.

Question 56

Choose the solvent below that would show the greatest boiling point elevation when used to make a 0.10 m nonelectrolyte solution.

A)CCl₄,K_b = 29.9°C/m
B)C₆H₆,K_b = 5.12°C/m
C)CH₃CH₂OCH₂CH₃,K_b = 1.79°C/m
D)CH₃CH₂OH,K_b = 1.99°C/m
E)CHCl₃,K_b = 4.70°C/m

Question 57

Determine the freezing point of a solution that contains 78.8 g of naphthalene (C₁₀H₈,molar mass = 128.16 g/mol)dissolved in 722 mL of benzene (d = 0.877 g/mL).Pure benzene has a melting point of 5.50°C and a freezing point depression constant of 4.90°C/m.

A)4.76°C
B)4.17°C
C)0.74°C
D)1.33°C
E)1.68°C

Question 58

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.

A)39.0 m
B)17.5 m
C)6.39 m
D)10.7 m
E)9.44 m

Question 59

Determine the vapor pressure of a solution at 55°C that contains 34.2 g NaCl in 375 mL of water.The vapor pressure of pure water at 55°C is 118.1 torr.

A)115 torr
B)87.1 torr
C)108 torr
D)112 torr
E)92.8 torr

Question 60

Determine the boiling point of a solution that contains 78.8 g of naphthalene (C₁₀H₈,molar mass = 128.16 g/mol)dissolved in 722 mL of benzene (d = 0.877 g/mL).Pure benzene has a boiling point of 80.1°C and a boiling point elevation constant of 2.53°C/m.

A)2.2°C
B)2.5°C
C)82.3°C
D)80.4°C
E)82.6°C

Question 61

What happens to a supersaturated solution of potassium acetate once it is cooled and a small crystal of solid potassium acetate is added?

Question 62

Match the following.
0.020 m NH₄Cl

A)largest van't Hoff factor
B)solution of ionic compound with highest freezing point
C)solution with ΔT_b = 0.026°C
D)highest boiling point
E)solution that is most strongly dependent upon pressure

Question 63

Identify the compound that would have the highest osmotic pressure when dissolved in water.

A)NaCl
B)K₂SO₄
C)MgCl₂
D)FeCl₃
E)MgSO₄

Question 64

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

A)0.200 m Ca(ClO₄)₂
B)0.200 m K₃PO₃
C)0.200 m HOCH₂CH₂OH
D)0.200 m Ba(NO₃)₂
E)These all have the same freezing point.

Question 65

Match the following.
0.050 m NaCl

A)largest van't Hoff factor
B)solution of ionic compound with highest freezing point
C)solution with ΔT_b = 0.026°C
D)highest boiling point
E)solution that is most strongly dependent upon pressure

Question 66

Match the following.
0.050 m C₆H₁₂O₆ (aqueous)

A)largest van't Hoff factor
B)solution of ionic compound with highest freezing point
C)solution with ΔT_b = 0.026°C
D)highest boiling point
E)solution that is most strongly dependent upon pressure

Question 67

Define molality.

Question 68

A compound is found to have a molar mass of 598 g/mol.If 35.8 mg of the compound is dissolved in enough water to make 175 mL of solution at 25°C,what is the osmotic pressure of the resulting solution?

A)3.42 torr
B)6.36 torr
C)5.01 torr
D)5.99 torr
E)8.36 torr

Question 69

Explain why the van't Hoff factor for MgCl₂ is less than it's predicted value.

Question 70

The boiling point of an aqueous 1.83 m (NH₄)₂SO₄ (molar mass = 132.15 g/mol)solution is 102.5°C.Determine the value of the van't Hoff factor for this solute if the K_b for water is 0.512°C/m.

A)3.0
B)3.6
C)1.8
D)2.7
E)2.3

Question 71

Why isn't pentanol (CH₃CH₂CH₂CH₂CH₂OH)very soluble in water?

Question 72

Define osmosis.

Question 73

Match the following.
0.010 m Al(NO₃)₃

A)largest van't Hoff factor
B)solution of ionic compound with highest freezing point
C)solution with ΔT_b = 0.026°C
D)highest boiling point
E)solution that is most strongly dependent upon pressure

Question 74

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

Question 75

Choose the aqueous solution below with the lowest freezing point.These are all solutions of nonvolatile solutes and you should assume ideal van't Hoff factors where applicable.

A)0.075 m NaI
B)0.075 m (NH₄)₃PO₄
C)0.075 m NaBrO₄
D)0.075 m LiCN
E)0.075 m KNO₂

Question 76

Place the following aqueous solutions of nonvolatile,nonionic compounds in order of decreasing osmotic pressure.
I.0.011 M sucrose
II.0.00095 M glucose
III.0.0060 M glycerin

A)I > III > II
B)I > II > III
C)II > III > I
D)III > I > II
E)II > I > III

Question 77

Match the following.
0.0050 m CO₂

A)largest van't Hoff factor
B)solution of ionic compound with highest freezing point
C)solution with ΔT_b = 0.026°C
D)highest boiling point
E)solution that is most strongly dependent upon pressure

Question 78

A 150.0 mL sample of an aqueous solution at 25°C contains 15.2 mg of an unknown nonelectrolyte compound.If the solution has an osmotic pressure of 8.44 torr,what is the molar mass of the unknown compound?

A)223 g/mol
B)294 g/mol
C)341 g/mol
D)448 g/mol
E)195 g/mol

Question 79

Calculate the osmotic pressure,in torr,of a solution containing 3.00 mg of a sugar (342 g/mole)in 15.0 mL of water at 25°C.

Question 80

What is a semipermeable membrane?