Question 1

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?

Accepted Answer

A)   0.87
B)   0.69
C)   0.32
D)   0.13
E)   0.045F) A) and C)
G) A) and B)

Question 2

Select the strongest electrolyte from the following set.

Accepted Answer

A)   CH3CH2OH, ethanol
B)   LiNO3
C)   C6H12O6, glucose
D)   CCl4
E)   HFF) A) and C)
G) A) and E)

Question 3

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

Accepted Answer

A) True 
 B)False

Question 4

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

Accepted Answer

A)   0.732 M
B)   0.865 M
C)   2.66 M
D)   4.97 M
E)   None of these choices is correct.F) C) and D)
G) A) and E) D

Question 5

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 °\degree° C. P  °\degree° hexane = 400.0 torr at 49.6 °\degree° C.

Accepted Answer

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

Question 6

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

Accepted Answer

A)   mass percent
B)   molality
C)   mole fraction
D)   molarity
E)   None of these choices is correct.F) B) and E)
G) C) and D)

Question 7

Heats of hydration may be either positive or negative.

Accepted Answer

A) True 
 B)False

Question 8

Procaine hydrochloride (м = 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.

Accepted Answer

A)   2.272 M
B)   4.056 M
C)   4.216 M
D)   4.666 M
E)   None of these choices is correct.F) A) and D)
G) C) and D)

Question 9

Soda drinks bubble when the bottle is opened because

Accepted Answer

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.F) A) and B)
G) C) and D)

Question 10

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

Accepted Answer

A)   0.10 m KOH
B)   0.10 m RbCl
C)   0.05 m CaSO4
D)   0.05 m BaCl2
E)   0.10 m K2SO4F) D) and E)
G) C) and D)

Question 11

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? (мsaccharin = 183.2 g/mol)

Accepted Answer

A)   0.0188 M
B)   0.632 M
C)   1.58 M
D)   3.45 M
E)   None of these choices is correct.F) All of the above
G) B) and E)

Question 12

Colligative properties depend on

Accepted Answer

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.F) B) and D)
G) C) and D)

Question 13

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

Accepted Answer

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)   They have none of these features in common.F) B) and C)
G) A) and D)

Question 14

Calculate the freezing point of a solution made by dissolving 3.50 g of potassium chloride (? = 74.55 g/mol)  in 100.0 g of water. Assume ideal behavior for the solution; Kf = 1.86 °\degree° C/m.

Accepted Answer

A)   -1.7 °\degree° C
B)   -0.9 °\degree° C
C)   0.0 °\degree° C
D)   0.9 °\degree° C
E)   1.7 °\degree° C F) A) and B)
G) C) and D)

Question 15

The Henry's Law constant (k)  for carbon monoxide in water at 25 °\degree° 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?

Accepted Answer

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 is correct. F) None of the above
G) B) and D)

Question 16

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

Accepted Answer

A)   NaBr
B)   CaS
C)   NaOH
D)   KI
E)   CsClF) A) and B)
G) D) and E)

Question 17

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

Accepted Answer

A)   0.75 m (NH4) 3PO4
B)   1.0 m CaSO4
C)   1.0 m LiClO4
D)   1.5 m CH3OH, methyl alcohol
E)   pure waterF) B) and D)
G) A) and B) A

Question 18

Determine the freezing point of a solution which contains 0.31 mol of sucrose in 175 g of water. Kf = 1.86 °\degree° C/m

Accepted Answer

A)   3.3 °\degree° C
B)   1.1 °\degree° C
C)   0.0 °\degree° C
D)   -1.1 °\degree° C
E)   -3.3 °\degree° C F) A) and E)
G) A) and D)

Question 19

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?

Accepted Answer

A)   0.87
B)   0.69
C)   0.32
D)   0.13
E)   0.045F) All of the above
G) C) and D) A

Question 20

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

Accepted Answer

A)   ?Hsoln > 0, entropy of system decreases
B)   ?Hsoln  ≈\approx≈  0, entropy of system decreases
C)   ?Hsoln  ≈\approx≈  0, entropy change of system  ≈\approx≈  0
D)   ?Hsoln  ≈\approx≈  0, entropy of system increases
E)   None of these choices is correct. F) A) and B)
G) B) and E)

Exam 13: The Properties of Mixtures: Solutions and Colloids

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?

Correct AnswerverifiedShow Answer

Select the strongest electrolyte from the following set.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedD

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 °\degree° C. P °\degree° hexane = 400.0 torr at 49.6 °\degree° C.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Heats of hydration may be either positive or negative.

Correct AnswerverifiedShow Answer

Procaine hydrochloride (м = 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.

Correct AnswerverifiedShow Answer

Soda drinks bubble when the bottle is opened because

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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? (мsaccharin = 183.2 g/mol)

Correct AnswerverifiedShow Answer

Colligative properties depend on

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Calculate the freezing point of a solution made by dissolving 3.50 g of potassium chloride (? = 74.55 g/mol) in 100.0 g of water. Assume ideal behavior for the solution; Kf = 1.86 °\degree° C/m.

Correct AnswerverifiedShow Answer

The Henry's Law constant (k) for carbon monoxide in water at 25 °\degree° 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?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedA

Determine the freezing point of a solution which contains 0.31 mol of sucrose in 175 g of water. Kf = 1.86 °\degree° C/m

Correct AnswerverifiedShow Answer

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?

Correct AnswerverifiedA

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

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

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

Correct Answer
verified
D

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 $\degree$ C. P $\degree$ _hexane = 400.0 torr at 49.6 $\degree$ C.

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

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? (м_saccharin = 183.2 g/mol)

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Calculate the freezing point of a solution made by dissolving 3.50 g of potassium chloride (? = 74.55 g/mol) in 100.0 g of water. Assume ideal behavior for the solution; K_f = 1.86 $\degree$ C/m.

Correct Answer
verified

The Henry's Law constant (k) for carbon monoxide in water at 25 $\degree$ 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?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
A

Determine the freezing point of a solution which contains 0.31 mol of sucrose in 175 g of water. K_f = 1.86 $\degree$ C/m

Correct Answer
verified

Correct Answer
verified
A

Correct Answer
verified