Question 1

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

Question 2

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

Question 3

Select the weakest electrolyte from the following set.

Accepted Answer

A)  Na2SO4 
B)  KCl 
C)  CH3CH2COOH, propionic acid 
D)  CaCl2 
E)  LiOH 
A)  Na2SO4 
B)  KCl 
C)  CH3CH2COOH, propionic acid 
D)  CaCl2 
E)  LiOH

Question 4

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. 
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 5

Heats of solution may be either positive or negative.

Accepted Answer

A) True 
 B)False

Question 6

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

Question 7

Ideal solutions do not conform to Raoult's Law.

Accepted Answer

A) True 
 B)False

Question 8

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. 
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.

Question 9

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. 
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.

Question 10

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

Accepted Answer

A) True 
 B)False

Question 11

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 12

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

Question 13

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

Question 14

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

Question 15

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. 
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 16

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 17

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. 
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.

Question 18

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

Question 19

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

Question 20

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 water 
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 water

Exam 13: The Properties of Mixtures: Solutions and Colloids

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?

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

Select the weakest electrolyte from the following set.

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

Heats of solution may be either positive or negative.

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

Ideal solutions do not conform to Raoult's Law.

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?

The Tyndall effect

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

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

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?

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?

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

When two pure substances are mixed to form a solution

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.

An emulsion is a dispersion consisting of a

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?

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

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

Keys to the Study of Chemistry

The Components of Matter

Stoichiometry of Formulas and Equations

Three Major Classes of Chemical Reactions

Gases and the Kinetic-Molecular Theory

Thermochemistry: Energy Flow and Chemical Change

Quantum Theory and Atomic Structure

Electron Configuration and Chemical Periodicity

Models of Chemical Bonding

The Shapes of Molecules

Theories of Covalent Bonding

Intermolecular Forces: Liquids, Solids, and Phase Changes

Periodic Patterns in the Main-Group Elements

Organic Compounds and the Atomic Properties of Carbon

Kinetics: Rates and Mechanisms of Chemical Reactions

Equilibrium: the Extent of Chemical Reactions

Acid-Base Equilibria

Ionic Equilibria in Aqueous Systems

Thermodynamics: Entropy, Free Energy, and the Direction of Chemical Reactions

Electrochemistry: Chemical Change and Electrical Work

The Elements in Nature and Industry

The Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

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

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

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

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

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