Deck 13: The Properties of Mixtures: Solutions and Colloids

Question 1

Select the type of interaction that best describes the attraction between Mg²⁺ ions and water molecules.

A)dipole-dipole
B)dipole-induced dipole
C)ion-dipole
D)ion-induced dipole
E)ion-hydrogen bond

Answer 1

ion-dipole

Question 2

In general, water is a good solvent for both polar and nonpolar compounds.

Answer 2

False

Question 3

The solubility of gases in water increases with increase in the pressure of the gas.

Answer 3

True

Question 4

The heat of solution is the total enthalpy change when a solution is formed from the separated solute and solvent.

Question 5

Under physiological conditions, amino acids in solution carry

A)no electrical charges.
B)a net positive charge, due to an −NH ₃ ⁺ group or groups.
C)a net negative charge, due to a −COO ⁻ group or groups.
D)both −NH ₂ and −COOH groups.
E)both −NH ₃ ⁺ and −COO ⁻ groups.

Question 6

Gases with high boiling points tend to be more soluble in water than ones with low boiling points.

Question 7

The most abundant molecules in the cell membranes of most species are

A)proteins.
B)sugars.
C)phospholipids.
D)fatty acids.
E)steroids.

Question 8

The backbone of a protein chain consists of carbon, nitrogen, and oxygen atoms.

Question 9

Heats of solution may be either positive or negative.

Question 10

If the density of a solution is less than 1.0 g/mL, its molarity will be greater than its molality.

Question 11

Which, if any, of the following features is common to soaps, detergents, phospholipids, and channel-forming antibiotics?

A)They all contain fatty acids.
B)They all contain phosphate groups.
C)They all contain polypeptide chains.
D)Their function depends on the dual polarity of their molecules.
E)None of these choices are correct.

Question 12

Raoult's Law relates the vapor pressure of a solvent above a solution to the mole fraction of the solvent and the vapor pressure of the pure solvent.

Question 13

Helical segments of protein molecules arise through hydrogen bonding between C=O and N-H groups.

Question 14

The shape of a protein molecule is determined completely by

A)hydrogen bonding.
B)ion-dipole attractions.
C)dispersion forces.
D)disulfide bridges.
E)the sequence of amino acids in the chain.

Question 15

Colloidal particles may be solids, liquids, or gases.

Question 16

Heats of hydration may be either positive or negative.

Question 17

All solutions are mixtures

Question 18

Ideal solutions do not conform to Raoult's Law.

Question 19

The larger the ion, the greater in magnitude will be its heat of hydration.

Question 20

Electrolyte solutions generally behave less ideally as the solute concentration increases.

Question 21

A saturated solution of carbon dioxide in water contains 3.00 g of CO₂ when the CO₂ partial pressure is 8.0 atm. What mass of CO₂ will escape if the partial pressure is lowered to 3.2 atm?

A)0.90 g
B)1.20 g
C)1.40 g
D)1.80 g
E)2.20 g

Question 22

Calculate the molarity of a solution prepared by diluting 1.85 L of 6.5 M KOH to 11.0 L.

A)0.28 M
B)0.91 M
C)1.1 M
D)3.1 M
E)3.9 M

Question 23

Methane has a Henry's Law constant (k) of 9.88 × 10⁻² mol/(L·atm) when dissolved in benzene at 25°C. How many grams of CH₄ will dissolve in 3.00 L of benzene if the partial pressure of CH₄ is 1.48 atm?

A)0.0667 g
B)0.146 g
C)2.34 g
D)4.83 g
E)7.02 g

Question 24

For a given solution, which of the following concentration values will change as temperature changes?

A)Mass percent
B)Molality
C)Mole fraction
D)Molarity
E)None of these choices are correct.

Question 25

A solution of sucrose (sugar) in water is in equilibrium with solid sucrose. If more solid sucrose is now added, with stirring,

A)the concentration of the solution will increase.
B)the concentration of the solution will decrease.
C)the concentration of the solution will remain the same.
D)the volume of solution will increase.
E)a supersaturated solution will be produced.

Question 26

Consider the expression below, showing the terms which contribute to the heat of solution, ΔH_soln: ΔH_soln = ΔH_solute + ΔH_solvent + ΔH_mix
Which of the following sets correctly shows the signs (positive or negative) of the three terms on the right hand side of the equation?

A)Δ H _solute > 0; Δ H _solvent > 0; Δ H _mix > 0
B)Δ H _solute < 0; Δ H _solvent < 0; Δ H _mix < 0
C)Δ H _solute > 0; Δ H _solvent > 0; Δ H _mix < 0
D)Δ H _solute < 0; Δ H _solvent < 0; Δ H _mix > 0
E)Δ H _solute < 0; Δ H _solvent > 0; Δ H _mix < 0

Question 27

Based only on the relative lattice energies of the compounds below, which one would be expected to have the lowest solubility in water?

A)NaBr
B)CaS
C)NaOH
D)KI
E)CsCl

Question 28

If a solute dissolves in an endothermic process

A)H bonds must exist between solvent and solute.
B)strong ion-dipole forces must exist in the solution.
C)the solute must be a gas.
D)the entropy of the solution is immaterial.
E)the entropy of the solution must be greater than that of its pure components.

Question 29

When two pure substances are mixed to form a solution

A)heat is released.
B)heat is absorbed.
C)there is an increase in entropy.
D)there is a decrease in entropy.
E)entropy is conserved.

Question 30

Potassium hydrogen phosphate is used in the preparation of nondairy powdered creamers. Calculate the molarity of a solution prepared by dissolving 238 g of K₂HPO₄ in enough water to produce 275 mL of solution.

A)0.732 M
B)0.865 M
C)2.66 M
D)4.97 M
E)None of these choices are correct.

Question 31

Which of the following pairs of ions is arranged so that the ion with the smaller charge density is listed first?

A)K ⁺, Rb ⁺
B)Cl ⁻, K ⁺
C)Cl ⁻, Br ⁻
D)Ca ²⁺, Ba ²⁺
E)None of these choices are correct.

Question 32

The Henry's Law constant (k) for carbon monoxide in water at 25°C is 9.71 × 10⁻⁴ mol/(L·atm). How many grams of CO will dissolve in 1.00 L of water if the partial pressure of CO is 2.75 atm?

A)3.53 × 10 ⁻⁴ g
B)2.67 × 10 ⁻³ g
C)9.89 × 10 ⁻³ g
D)7.48 × 10 ⁻² g
E)None of these choices are correct.

Question 33

Which of the following ions will be expected to have the most negative heat of hydration, ΔH_hydr?

A)Na ⁺
B)Cs ⁺
C)Ca ²⁺
D)F ⁻
E)I ⁻

Question 34

Which of the following sets of conditions could exist when two liquids which are completely miscible in one another are mixed?

A)Δ H _soln > 0, entropy of system decreases
B)Δ H _soln ≈ 0, entropy of system decreases
C)Δ H _soln ≈ 0, entropy change of system ≈ 0
D)Δ H _soln ≈ 0, entropy of system increases
E)None of these choices are correct.

Question 35

Which of the following statements describes the correct method of preparation of 1.00 L of a 2.0 M urea solution? ℳ_urea = 60.06 g/mol

A)Dissolve 120 g of urea in 1.00 kg of distilled water.
B)Dissolve 120 g of urea in 880 g of distilled water.
C)Dissolve 120 g of urea in enough distilled water to produce 1.00 L of solution.
D)Dissolve 120 g of urea in 1.00 liter of distilled water.
E)The density of urea is needed in order to do this calculation.

Question 36

Potassium fluoride is used for frosting glass. Calculate the molarity of a solution prepared by dissolving 78.6 g of KF in enough water to produce 225 mL of solution.

A)0.304 M
B)0.349 M
C)1.35 M
D)3.29 M
E)6.01 M

Question 37

What volume of concentrated (14.7 M) phosphoric acid is needed to prepare 25.0 L of 3.0 M H₃PO₄?

A)0.20 L
B)0.57 L
C)1.8 L
D)3.6 L
E)5.1 L

Question 38

Which of the following pairs of ions is arranged so that the ion with the larger (i.e., more negative) heat of hydration is listed first?

A)Br ⁻, K ⁺
B)Mg ²⁺, Sr ²⁺
C)Ca ²⁺, Sc ³⁺
D)Na ⁺, Li ⁺
E)None of these choices are correct.

Question 39

Soda drinks bubble when the bottle is opened because

A)the temperature of the soda increases.
B)exposure to atmospheric pressure squeezes the carbon dioxide from solution.
C)the partial pressure of carbon dioxide above the solution is reduced.
D)atmospheric nitrogen molecules displace carbon dioxide molecules.
E)the Henry's law constant changes due to the change in pressure.

Question 40

Saccharin, one of the first non-nutritive sweeteners used in soft-drinks, is 500 times sweeter than sugar in dilute aqueous solutions. The solubility of saccharin is 1.00 gram per 290 mL of solution. What is the molarity of a saturated saccharin solution? (ℳ_saccharin = 183.2 g/mol)

A)0.0188 M
B)0.632 M
C)1.58 M
D)3.45 M
E)None of these choices are correct.

Question 41

The concentration of iodine in sea water is 60. parts per billion by mass. If one assumes that the iodine exists in the form of iodide anions, what is the molarity of iodide in sea water? (The density of sea water is 1.025 g/mL.)

A)4.8 × 10 ⁻¹³ M
B)4.8 × 10 ⁻¹⁰ M
C)4.8 × 10 ⁻⁷ M
D)4.7 × 10 ⁻⁴ M
E)4.7 × 10 ⁻¹ M

Question 42

Cadmium bromide is used in photography and lithography. Calculate the molality of a solution prepared by dissolving 45.38 g of CdBr₂ in 375.0 g of water.

A)0.03035 m
B)0.01600 m
C)0.1210 m
D)0.4446 m
E)None of these choices are correct.

Question 43

What is the molality of a solution prepared by dissolving 86.9 g of diethyl ether, C₄H₁₀O, in 425 g of benzene, C₆H₆?

A)0.362 m
B)0.498 m
C)2.01 m
D)2.76 m
E)None of these choices are correct.

Question 44

Children under the age of 6 with more than 0.10 ppm of lead in their blood can suffer a reduction in I.Q. or have behavior problems. What is the molality of a solution which contains 0.10 ppm of lead?

A)4.8 × 10 ⁻¹⁰ m
B)4.8 × 10 ⁻⁷ m
C)4.8 × 10 ⁻⁴ m
D)4.8 × 10 ⁻¹ m
E)None of these choices are correct.

Question 45

Sodium hydroxide is a common ingredient in drain cleaners such as Drano. The mole fraction of sodium hydroxide in a saturated aqueous solution is 0.310. What is the molality of the solution?

A)0.310 m
B)0.690 m
C)1.24 m
D)12.4 m
E)25.0 m

Question 46

A solution of ethanol (C₂H₆O) in water is sometimes used as a disinfectant. 1.00 L of this solution contains 553 g of ethanol and 335 g of water. What is the mole fraction of ethanol in this solution?

A)0.377
B)0.392
C)0.553
D)0.608
E)0.623

Question 47

Procaine hydrochloride (ℳ = 272.77 g/mol) is used as a local anesthetic. Calculate the molarity of a 4.666 m solution which has a density of 1.1066 g/mL.

A)2.272 M
B)4.056 M
C)4.216 M
D)4.666 M
E)None of these choices are correct.

Question 48

The chemist, Anna Lytic, must prepare 1.00 kg of 15.0% (w/w) acetic acid using a stock solution which is 36.0% (w/w) acetic acid (d = 1.045 g/mL). Which of the following combinations will give her the solution she wants?

A)417 mL of 36% acetic acid in 583 mL of distilled water
B)417 g of 36% acetic acid in 583 g of distilled water
C)360 mL of 36% acetic acid in 640 mL of distilled water
D)360 g of 36% acetic acid in 640 g of distilled water
E)150 g of 36% acetic acid in 850 g of distilled water

Question 49

Aqueous ammonia is commercially available in a solution that is 28% (w/w) ammonia. What is the mole fraction of ammonia in such a solution?

A)0.017
B)0.023
C)0.012
D)0.24
E)0.29

Question 50

The mole fraction of potassium nitrate in an aqueous solution is 0.0194. The solution's density is 1.0627 g/mL. Calculate the molarity of the solution.

A)0.0194 M
B)0.981 M
C)1.05 M
D)1.96 M
E)19.4 M

Question 51

A solution of ethanol (C₂H₆O) in water is sometimes used as a disinfectant. 1.00 L of this solution contains 553 g of ethanol and 335 g of water. What is the molality of the ethanol in this solution?

A)0.392 m
B)0.608 m
C)13.5 m
D)33.6 m
E)35.8 m

Question 52

Colligative properties depend on

A)the chemical properties of the solute.
B)the chemical properties of the solvent.
C)the masses of the individual ions.
D)the molar mass of the solute.
E)the number of particles dissolved.

Question 53

Isoamyl salicylate (ℳ = 208.25 g/mol) has a pleasant aroma and is used in perfumes and soaps. Which of the following combinations gives a 0.75 m solution of isoamyl salicylate in ethyl alcohol (d = 0.7893 g/mL)?

A)117.2 g isoamyl salicylate in 950.0 mL of ethyl alcohol
B)117.2 g isoamyl salicylate in 750.0 mL of ethyl alcohol
C)117.2 g isoamyl salicylate in 750.0 mL of solution
D)117.2 g isoamyl salicylate in 592.0 g of ethyl alcohol
E)None of these choices are correct.

Question 54

The solubility of the oxidizing agent potassium permanganate is 7.1 g per 100.0 g of water at 25°C. What is the mole fraction of potassium permanganate in this solution?

A)0.0080
B)0.0086
C)0.066
D)0.45
E)0.48

Question 55

Calcium nitrite is used as a corrosion inhibitor in lubricants. What is the molality of a solution prepared by dissolving 18.5 g of calcium nitrite in 83.5 g of distilled water?

A)0.0342 m
B)0.0855 m
C)0.222 m
D)0.444 m
E)1.68 m

Question 56

Raoult's Law relates the vapor pressure of the solvent above the solution to its mole fraction in the solution. Which of the following is an accurate statement?

A)Raoult's Law applies exactly to all solutions.
B)Raoult's Law works best when applied to concentrated solutions.
C)Raoult's Law works best when applied to dilute solutions.
D)Raoult's Law applies only to non-ideal solutions.
E)None of these choices are correct.

Question 57

What is the mole fraction of Ne in a mixture containing 10.1 g of Ne, 79.9 g of Ar, and 83.8 g of Kr?

A)0.40
B)0.25
C)0.20
D)0.14
E)0.058

Question 58

A 2.0% (w/v) solution of sodium hydrogen citrate, Na₂C₆H₆O₇, which also contains 2.5% (w/v) of dextrose, C₆H₁₂O₆, is used as an anticoagulant for blood which is to be used for transfusions. What is the molarity of the sodium hydrogen citrate in the solution?

A)0.085 M
B)0.19 M
C)0.53 M
D)1.2 M
E)1.3 M

Question 59

A 0.89% (w/v) sodium chloride solution is referred to as physiological saline solution because it has the same concentration of salts as human blood. What is the molarity of a physiological saline solution?

A)0.0028 M
B)0.015 M
C)0.15 M
D)0.30 M
E)0.35 M

Question 60

Copper(II) bromide is used as a wood preservative. What mass of CuBr₂ is needed to prepare 750.0 mL of a 1.25 M solution?

A)134 g
B)209 g
C)372 g
D)938 g
E)> 1 kg

Question 61

How many moles of bromide ions are present in 750.0 mL of 1.35 M MgBr₂?

A)0.506 mol
B)1.01 mol
C)2.03 mol
D)3.04 mol
E)None of these choices are correct.

Question 62

Diethyl ether has a vapor pressure of 400.0 torr at 18°C. When a sample of benzoic acid is dissolved in ether, the vapor pressure of the solution is 342 torr. What is the mole fraction of benzoic acid in the solution?

A)0.0169
B)0.0197
C)0.145
D)0.855
E)None of these choices are correct.

Question 63

How many moles of sulfate ions are present in 1.0 L of 0.5 M Li₂SO₄?

A)0.5 mol
B)1.0 mol
C)1.5 mol
D)2.0 mol
E)3.0 mol

Question 64

How many moles of solute particles are present in 100.0 mL of 2.50 M (NH₄)₃PO₄?

A)0.100 mol
B)0.250 mol
C)0.500 mol
D)0.750 mol
E)1.00 mol

Question 65

Which of the following aqueous liquids will have the lowest freezing point?

A)0.5 m C ₁₂H ₂₂O _{11 (sucrose)}
B)0.5 m Ca(NO ₃)₂
C)0.5 m NiSO ₄
D)0.5 m Li ₃PO ₄
E)Pure water

Question 66

Calculate the vapor pressure of a solution prepared by dissolving 0.500 mol of a non-volatile solute in 275 g of hexane (ℳ = 86.18 g/mol) at 49.6°C. P°_hexane = 400.0 torr at 49.6°C.

A)54 torr
B)154 torr
C)246 torr
D)346 torr
E)400. torr

Question 67

Two aqueous solutions are prepared: 2.0 m Cu(NO₃)₂ and 2.0 m NaBr. Which of the following statements is true?

A)The Cu(NO ₃)₂ solution has a higher vapor pressure and lower freezing point than the NaBr solution.
B)The Cu(NO ₃)₂ solution has a higher vapor pressure and higher freezing point than the NaBr solution.
C)The Cu(NO ₃)₂ solution has a lower vapor pressure and lower freezing point than the NaBr solution.
D)The Cu(NO ₃)₂ solution has a lower vapor pressure and higher freezing point than the NaBr solution.
E)None of these choices are correct.

Question 68

From the following list of aqueous solutions and water, select the one with the lowest freezing point.

A)0.75 m (NH ₄)₃PO ₄
B)1.0 m CaSO ₄
C)1.0 m LiClO ₄
D)1.5 m CH ₃OH, methyl alcohol
E)pure water

Question 69

The vapor pressure of pure acetone (propanone) is 266 torr. When a non-volatile solute is added, the vapor pressure of acetone above the solution falls to 232 torr. What is the mole fraction of the non-volatile solute in the solution?

A)0.87
B)0.69
C)0.32
D)0.13
E)0.045

Question 70

Select the strongest electrolyte from the following set.

A)CH ₃CH ₂OH, ethanol
B)LiNO ₃
C)C ₆H ₁₂O ₆, glucose
D)CCl ₄
E)HF

Question 71

Select the weakest electrolyte from the following set.

A)Na ₂ SO ₄
B)KCl
C)CH ₃ CH ₂ COOH, propionic acid
D)CaCl ₂
E)LiOH

Question 72

Which of the following aqueous solutions will have the lowest osmotic pressure?

A)0.10 m KOH
B)0.10 m RbCl
C)0.05 m CaSO ₄
D)0.05 m BaCl ₂
E)0.10 m K ₂SO ₄

Question 73

Which of the following aqueous solutions should demonstrate the most non-ideal behavior?

A)0.1 M NaI
B)0.2 M CuSO ₄
C)0.5 M KBr
D)2.0 M CuCl ₂
E)2.0 M CsCl

Question 74

Safrole is used as a topical antiseptic. Calculate the vapor pressure of a solution prepared by dissolving 0.75 mol of safrole in 950 g of ethanol (ℳ = 46.07 g/mol). P°_ethanol = 50.0 torr at 25°C.

A)1.8 torr
B)11 torr
C)15 torr
D)40 torr
E)48 torr

Question 75

Determine the freezing point of a solution that contains 0.31 mol of sucrose in 175 g of water. K_f = 1.86°C/m

A)3.3°C
B)1.1°C
C)0.0°C
D)−1.1°C
E)−3.3°C

Question 76

The vapor pressure of pure acetone (propanone) is 266 torr. When a non-volatile solute is added, the vapor pressure of acetone above the solution falls to 232 torr. What is the mole fraction of acetone in the solution?

A)0.87
B)0.69
C)0.32
D)0.13
E)0.045

Question 77

What concentration of aqueous FeCl₃ would have the same osmotic pressure as a 0.20 M solution of CaCl₂ at the same temperature, assuming ideal behavior?

A)0.60 M
B)0.40 M
C)0.30 M
D)0.15 M
E)0.10 M

Question 78

Which of the following aqueous solutions should demonstrate the most ideal behavior?

A)0.1 M K ₂SO ₄
B)0.1 M CaCl ₂
C)3.0 M LiF
D)0.1 M MgSO ₄
E)0.1 M NaCl

Question 79

From the following list of aqueous solutions and water, select the one with the highest boiling point.

A)1.0 m KNO ₃
B)0.75 m NaCl
C)0.75 m CuCl ₂
D)2.0 m C ₁₂H ₂₂O ₁₁ (sucrose)
E)pure water

Question 80

Two aqueous are prepared: 1.00 m Na₂CO₃ and 1.00 m LiCl. Which of the following statements is true?

A)The Na ₂CO ₃ solution has a higher osmotic pressure and higher vapor pressure than the LiCl solution.
B)The Na ₂CO ₃ solution has a higher osmotic pressure and higher boiling point than the LiCl solution.
C)The Na ₂CO ₃ solution has a lower osmotic pressure and lower vapor pressure than the LiCI solution.
D)The Na ₂CO ₃ solution has a lower osmotic pressure and higher boiling point than the LiCl solution.
E)None of these choices are correct.