Deck 14: Solutions

Question 1

Give the major force in seawater.

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

Answer 1

ion-dipole

Question 2

Which of the following statements is generally 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.

Answer 2

The solubility of a solid is highly dependent on temperature.

Question 3

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.

Answer 3

When <

Question 4

A solution containing less than the equilibrium amount is called

A) an unsaturated solution.
B) a dilute solution.
C) a supersaturated solution.
D) a concentrated solution.
E) a saturated solution.

Question 5

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 6

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 7

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 8

Determine DH_solute for KBr if the DH_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 9

A solution containing more than the equilibrium amount is called

A) an unsaturated solution.
B) a dilute solution.
C) a supersaturated solution.
D) a concentrated solution.
E) a saturated solution.

Question 10

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 11

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 12

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 13

Give the major force between acetone and chloroform.

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

Question 14

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 15

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 ethanol.

Question 16

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 given that k_H for O₂ is 1.3 × 10^-3 M/ atm at this temperature.

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

Question 17

Give the major force between ethanol and water.

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

Question 18

A solid can be purified through what technique?

A) recrystallization
B) dilution
C) dissolution
D) boiling
E) melting

Question 19

A sealed container contains 0.352 L of water with an atmosphere of oxygen gas.What is the concentration of O₂ in the water if the external pressure is 4.24 atm given that k_H for O₂ is 1.66 × 10^-6 M/mm Hg at this temperature?

A) 5.34 × 10^-3 M
B) 1.53 × 10^-3 M
C) 9.46 × 10^-2 M
D) 5.34 × 10^-2 M
E) 3.82 × 10^-4 M

Question 20

Identify the polar solvent.

A) acetone
B) hexane
C) diethyl ether
D) toluene
E) carbon tetrachloride

Question 21

What is the mol fraction of ethanol,C₂H₅OH,in a solution of 75.3g of ethanol and 525g of water?

A) 0.0531
B) 0.127
C) 0.947
D) 0.239
E) 0.0237

Question 22

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 23

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 24

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 25

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 26

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 27

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 28

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 29

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 30

What mass of NaCl is contained in 24.88 g of a 15.00% by mass solution of NaCl in water?

A) 20.00 g
B) 21.15 g
C) 3.73 g
D) 1.50 g
E) 12.44 g

Question 31

A solution is prepared by dissolving 1.928 g of KNO3 into enough water to make 651 mL.What is the molarity of the solution?

A) 0.159 M
B) 0.381 M
C) 0.0293 M
D) 2.48 M
E) 0.0832 M

Question 32

Give the term for the amount of solute in moles per kilogram of solvent.

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

Question 33

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) 2.01 m
E) 4.98 m

Question 34

Give the term for the amount of solute in moles per liter of solution.

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

Question 35

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 36

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 37

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 38

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 39

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 40

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 41

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 42

Determine the freezing point of a solution that contains 62.8 g of urea (CH₄N₂O)dissolved in 275 g of water (K_f= 1.86°C/m).

A) -7.07°C
B) -4.82°C
C) -13.1°C
D) -3.01°C
E) -9.12°C

Question 43

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 44

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 45

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 46

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 47

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.The van't Hoff factor for NaCl is 1.9.

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

Question 48

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 49

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 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

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 52

The vapor pressure of a solution is always that of the pure solvent

A) equal to
B) twice
C) one half
D) higher than
E) lower than

Question 53

Solutions having osmotic pressures less than those of body fluids are called

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

Question 54

Determine the vapor pressure of a solution at 25°C that contains 85.3 g of naphthalene (C₁₀H₈)in 540 g of benzene (C₆H₆).The vapor pressure of benzene at 25°C is 74.6 torr.

A) 74.6 toff.
B) 68.0 torr.
C) 54.9 torr.
D) 7.52 torr.
E) 22.4 toff.

Question 55

________ is applied to roads in wintertime so that the ice will melt at a lower temperature.

A) Antifreeze
B) Water
C) Salt
D) Sugar
E) Oil

Question 56

What is the molecular weight of a polymer if 3.50 g are dissolved in enough water to give 252 mL of the solution and give a osmotic pressure of 28.52 mm Hg at 25°C?

A) 6.49 × 10⁵ g/mol
B) 9.05 × 10³ g/mol
C) 2.63 × 10³ g/mol
D) 28.5 g/mol
E) 8.88 × 10⁴ g/mol

Question 57

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

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

Question 58

how many grams of CCl₄ are needed to make a 1.20 m solution in 450g of octane?

A) 127.4 g
B) 184.6 g
C) 221.5 g
D) 83.06 g
E) 62.22 g

Question 59

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) 2.18°C
D) 3.33°C
E) 0.654°C

Question 60

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 61

What mass of water is required to give an aqueous solution containing 0.265 mol of MgCl₂ with a freezing point of -3.8°C? (Van't Hoff factor of MgCl₂ is 2.7)

A) 1.25 kg
B) 0.538 kg
C) 0.113 kg
D) 0.882 kg
E) 0.350 kg

Question 62

Identify the gas that is dissolved in carbonated sodas.

A) carbon dioxide
B) hydrogen
C) neon
D) carbon monoxide
E) argon

Question 63

Identify the compound whose solubility decreases with increasing temperature.

A) Na₂SO₄
B) K₂Cr₂O₇
C) NaNO₃
D) KClO₃
E) CaCl₂

Question 64

Identify the compounds that are soluble in both water and hexane.

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

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 270.mm Hg?

A) 0.0565 mol/L
B) 0.355 mol/L
C) 0.448 mol/L
D) 42.9 mol/L

Question 66

What is the osmotic pressure of a solution of 55.8 g of sucrose (C₁₂H₂₂O₁₁)in 200 mL of water at room temperature?

A) 19.9 atm
B) 1.67 atm
C) 6.27 atm
D) 11.5 atm
E) 14.4 atm

Question 67

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

A) Ne
B) CO
C) Br₂
D) CH₃CH₃
E) CO₂

Question 68

A student makes a solution containing 125g of acetonitrile (CH₃CN)and 300g of water.What is the mol fraction of acetonitrole?

A) 0.845
B) 0.155
C) 0.294
D) 0.706
E) 0.0453

Question 69

The Henry's law constant for helium gas in water at 30°C is 3.70 × 10^-4 M/atm.When the partial pressure of helium above a sample of water is 0.650 atm,the concentration of helium in the water is ________ M.

A) 5.69 × 10^-4
B) 1.76 × 10³
C) 1.30
D) 2.41 × 10^-4
E) 3.70 × 10^-4

Question 70

Identify the compound whose solubility is least affected by temperature.

A) K Cl
B) K₂Cr₂O₇
C) NaNO₃
D) Pb(NO₃)₃
E) NaCl

Question 71

Dissolving can be defined as

A) rate of dissolution = rate of deposition.
B) rate of dissolution < rate of deposition.
C) rate of dissolution > rate of deposition.
D) rate of bubbling > rate of dissolving
E) rate of condensing > rate of bubbling

Question 72

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

A) Na⁺
B) Ba²⁺
C) Al³⁺
D) Ca²⁺
E) Sr²⁺

Question 73

Parts per billion requires a multiplication factor of

A) 10^-9
B) 10^-3
C) 10³
D) 10⁶
E) 10⁹

Question 74

Determine the solubility of CO₂ in soda water at 25°C if the pressure of CO₂ is 5.6 atm.The Henry's law constant for carbon dioxide in water at this temperature is 3.4 × 10^-2 M/atm.

A) 0.16 M
B) 0.53 M
C) 0.61 M
D) 0.19 M
E) 0.78 M

Question 75

Which cation in each set is expected to have the larger (more negative)hydration energy?
I Be²⁺ or Ca²⁺
II Rb⁺ or Zn²⁺

A) Be²⁺ in set I and Rb⁺ in set II
B) Be²⁺ in set I and Zn²⁺ in set II
C) Ca²⁺ in set I and Rb⁺ in set II
D) Ca²⁺ in set I and Zn²⁺ in set II

Question 76

A fluid with as osmotic pressure greater than those of bodily fluids are referred to as

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

Question 77

Determine the solubility of N₂ in water exposed to air at 25°C if the atmospheric pressure is 2.0 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) 1.6 × 10^-4 M
B) 6.4 × 10^-4 M
C) 9.5 × 10^-4 M
D) 1.1 × 10^-4 M
E) 1.2 × 10^-4 M

Question 78

Dynamic equilibrium can be defined as

A) rate of dissolution = rate of deposition.
B) rate of dissolution < rate of deposition.
C) rate of dissolution > rate of deposition.
D) rate of bubbling > rate of dissolving
E) rate of condensing > rate of bubbling

Question 79

Determine the partial pressure of oxygen necessary to form an aqueous solution that is 6.5 × 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) 1.2 atm
B) 0.85 atm
C) 0.78 atm
D) 2.0 atm
E) 0.50 atm

Question 80

Which of the following compounds will be most soluble in nonane (C₉H₂₀)?

A) pentanol (CH₃CH₂CH₂CH₂CH₂OH)
B) benzene (C₆H₆)
C) acetic acid (CH₃CO₂H)
D) ethyl methyl ketone (CH₃CH₂COH₃)
E) None of these compounds should be soluble in pentane.