Question 1

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?

Accepted Answer

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

Question 2

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

Accepted Answer

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.F) D) and E)
G) C) and E)

Question 3

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

Accepted Answer

A) True 
 B)False

Question 4

The Tyndall effect

Accepted Answer

A)   is observed in concentrated solutions.
B)   is observed only in dilute solutions.
C)   is observed in colloidal dispersions.
D)   is caused by Brownian motion.
E)   is used to determine the osmotic pressure of solutions.F) A) and B)
G) D) and E)

Question 5

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.

Accepted Answer

A) True 
 B)False

Question 6

An emulsion is a dispersion consisting of a

Accepted Answer

A)   solid in a liquid.
B)   liquid in a liquid.
C)   gas in a liquid.
D)   liquid in a solid.
E)   gas in a solid.F) A) and C)
G) C) and E)

Question 7

Select the weakest electrolyte from the following set.

Accepted Answer

A)   Na2SO4
B)   KCl
C)   CH3CH2COOH, propionic acid
D)   CaCl2
E)   LiOHF) A) and B)
G) A) and C)

Question 8

When two pure substances are mixed to form a solution

Accepted Answer

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

Question 9

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

Accepted Answer

A)   0.5 m C12H22O11 (sucrose) 
B)   0.5 m Ca(NO3) 2
C)   0.5 m NiSO4
D)   0.5 m Li3PO4
E)   pure waterF) A) and D)
G) B) and E)

Question 10

Lysine is an amino acid that is an essential part of nutrition but which is not synthesized by the human body. What is the molar mass of lysine if 750.0 mL of a solution containing 8.60 g of lysine has an osmotic pressure of 1.918 atm? Temperature = 25.0 °\degree° C

Accepted Answer

A)   110. g/mol
B)   146 g/mol
C)   220. g/mol
D)   1340 g/mol
E)   1780 g/mol F) B) and E)
G) A) and E)

Question 11

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?

Accepted Answer

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 is correct.F) All of the above
G) B) and D)

Question 12

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

Accepted Answer

A)   0.40
B)   0.25
C)   0.20
D)   0.14
E)   0.058F) B) and C)
G) A) and E)

Question 13

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

Accepted Answer

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

Question 14

Hexachlorophene is used as a disinfectant in germicidal soaps. What mass of hexachlorophene (? = 406.9 g/mol)  must be added to 125 g of chloroform to give a solution with a boiling point of 62.60 °\degree° C? Kb = 3.63 °\degree° C/m, boiling point of pure chloroform = 61.70 °\degree° C

Accepted Answer

A)   12.6 g
B)   17.2 g
C)   31.0 g
D)   34.4 g
E)   101 g F) B) and E)
G) A) and D)

Question 15

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

Accepted Answer

A) True 
 B)False

Question 16

Heats of solution may be either positive or negative.

Accepted Answer

A) True 
 B)False

Question 17

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?

Accepted Answer

A)   0.017
B)   0.023
C)   0.012
D)   0.24
E)   0.29F) C) and D)
G) A) and E)

Question 18

Dimethylglyoxime, DMG, is an organic compound used to test for aqueous nickel(II)  ions. A solution prepared by dissolving 65.0 g of DMG in 375 g of ethanol boils at 80.3 °\degree° C. What is the molar mass of DMG? Kb = 1.22 °\degree° C/m, boiling point of pure ethanol = 78.5 °\degree° C

Accepted Answer

A)   44.1 g/mol
B)   65.8 g/mol
C)   117 g/mol
D)   131.6 g/mol
E)   553 g/mol F) B) and C)
G) B) and E)

Question 19

Ideal solutions do not conform to Raoult's Law.

Accepted Answer

A) True 
 B)False

Question 20

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?

Accepted Answer

A)   0.0028 M
B)   0.015 M
C)   0.15 M
D)   0.30 M
E)   0.35 MF) None of the above
G) B) and D)

Exam 13: The Properties of Mixtures: Solutions and Colloids

Dimethylglyoxime, DMG, is an organic compound used to test for aqueous nickel(II) ions. A solution prepared by dissolving 65.0 g of DMG in 375 g of ethanol boils at 80.3 °\degree° C. What is the molar mass of DMG? Kb = 1.22 °\degree° C/m, boiling point of pure ethanol = 78.5 °\degree° C

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Heats of solution may be either positive or negative.

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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.

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

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Lysine is an amino acid that is an essential part of nutrition but which is not synthesized by the human body. What is the molar mass of lysine if 750.0 mL of a solution containing 8.60 g of lysine has an osmotic pressure of 1.918 atm? Temperature = 25.0 °\degree° C

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The Tyndall effect

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When two pure substances are mixed to form a solution

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Select the weakest electrolyte from the following set.

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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?

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An emulsion is a dispersion consisting of a

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

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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?

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

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

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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?

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

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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?

Correct AnswerverifiedShow Answer

Ideal solutions do not conform to Raoult's Law.

Correct AnswerverifiedShow Answer

Hexachlorophene is used as a disinfectant in germicidal soaps. What mass of hexachlorophene (? = 406.9 g/mol) must be added to 125 g of chloroform to give a solution with a boiling point of 62.60 °\degree° C? Kb = 3.63 °\degree° C/m, boiling point of pure chloroform = 61.70 °\degree° C

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Dimethylglyoxime, DMG, is an organic compound used to test for aqueous nickel(II) ions. A solution prepared by dissolving 65.0 g of DMG in 375 g of ethanol boils at 80.3 $\degree$ C. What is the molar mass of DMG? K_b = 1.22 $\degree$ C/m, boiling point of pure ethanol = 78.5 $\degree$ C

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Correct Answer
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Correct Answer
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Lysine is an amino acid that is an essential part of nutrition but which is not synthesized by the human body. What is the molar mass of lysine if 750.0 mL of a solution containing 8.60 g of lysine has an osmotic pressure of 1.918 atm? Temperature = 25.0 $\degree$ C

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

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

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Correct Answer
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Correct Answer
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Hexachlorophene is used as a disinfectant in germicidal soaps. What mass of hexachlorophene (? = 406.9 g/mol) must be added to 125 g of chloroform to give a solution with a boiling point of 62.60 $\degree$ C? K_b = 3.63 $\degree$ C/m, boiling point of pure chloroform = 61.70 $\degree$ C

Correct Answer
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Correct Answer
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