Question 1

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

Accepted Answer

A)  0.1 M NaI 
B)  0.2 M CuSO4 
C)  0.5 M KBr 
D)  2.0 M CuCl2 
E)  2.0 M CsCl 
A)  0.1 M NaI 
B)  0.2 M CuSO4 
C)  0.5 M KBr 
D)  2.0 M CuCl2 
E)  2.0 M CsCl

Question 2

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?

Accepted Answer

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

Question 3

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 4

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

Accepted Answer

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

Question 5

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

Question 6

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

Accepted Answer

A) ΔHsolute > 0; ΔHsolvent > 0; ΔHmix > 0 B) ΔHsolute solvent mix solute > 0; ΔHsolvent > 0; ΔHmix solute solvent mix > 0 E) ΔHsolute solvent > 0; ΔHmix < 0 A) ΔHsolute > 0; ΔHsolvent > 0; ΔHmix > 0 B) ΔHsolute solvent mix solute > 0; ΔHsolvent > 0; ΔHmix solute solvent mix > 0 E) ΔHsolute solvent > 0; ΔHmix < 0

Question 7

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 8

A 0.100 m K2SO4 solution has a freezing point of -0.43°C. What is the van't Hoff factor for this solution? Kf = 1.86°C/m

Accepted Answer

A)  0.77 
B)  1.0 
C)  2.3 
D)  3.0 
E)  >3.0 
A)  0.77 
B)  1.0 
C)  2.3 
D)  3.0 
E)  >3.0

Question 9

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 (   = 46.07 g/mol). P°ethanol = 50.0 torr at 25°C.

Accepted Answer

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

Question 10

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?

Accepted Answer

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 
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 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 are 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 are correct.

Question 12

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.)

Accepted Answer

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 
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 13

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?

Accepted Answer

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

Question 14

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

Accepted Answer

A)  The Cu(NO3)2 solution has a higher vapor pressure and lower freezing point than the NaBr solution. 
B)  The Cu(NO3)2 solution has a higher vapor pressure and higher freezing point than the NaBr solution. 
C)  The Cu(NO3)2 solution has a lower vapor pressure and lower freezing point than the NaBr solution. 
D)  The Cu(NO3)2 solution has a lower vapor pressure and higher freezing point than the NaBr solution. 
E)  None of these choices are correct. 
A)  The Cu(NO3)2 solution has a higher vapor pressure and lower freezing point than the NaBr solution. 
B)  The Cu(NO3)2 solution has a higher vapor pressure and higher freezing point than the NaBr solution. 
C)  The Cu(NO3)2 solution has a lower vapor pressure and lower freezing point than the NaBr solution. 
D)  The Cu(NO3)2 solution has a lower vapor pressure and higher freezing point than the NaBr solution. 
E)  None of these choices are correct.

Question 15

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

Accepted Answer

A) True 
 B)False

Question 16

Cinnamaldehyde (   = 132.15 g/mol) is used as a flavoring agent. What mass of cinnamaldehyde must be added to 175 g of ethanol to give a solution whose boiling point is 82.7°C? Kb = 1.22°C/m, boiling point of pure ethanol = 78.5°C

Accepted Answer

A)  62.4 g 
B)  67.8 g 
C)  76.2 g 
D)  78.5 g 
E)  79.6 g 
A)  62.4 g 
B)  67.8 g 
C)  76.2 g 
D)  78.5 g 
E)  79.6 g

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

Question 18

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

Accepted Answer

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

Question 19

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 20

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.

Accepted Answer

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

Exam 13: The Properties of Mixtures Solutions and Colloids

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

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?

When two pure substances are mixed to form a solution

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

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? ( saccharin = 183.2 g/mol)

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

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

A 0.100 m K2SO4 solution has a freezing point of -0.43°C. What is the van't Hoff factor for this solution? Kf = 1.86°C/m

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 ( = 46.07 g/mol). P°ethanol = 50.0 torr at 25°C.

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?

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 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.)

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?

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

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

Cinnamaldehyde ( = 132.15 g/mol) is used as a flavoring agent. What mass of cinnamaldehyde must be added to 175 g of ethanol to give a solution whose boiling point is 82.7°C? Kb = 1.22°C/m, boiling point of pure ethanol = 78.5°C

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?

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

An emulsion is a dispersion consisting of a

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.

Keys to Studying Chemistry Definitions, Units, and Problem Solving

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 Reaction Direction

Electrochemistry Chemical Change and Electrical Work

The Elements in Nature and Industry

Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

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?

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

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 0.100 m K₂SO₄ solution has a freezing point of -0.43°C. What is the van't Hoff factor for this solution? K_f = 1.86°C/m

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 ( = 46.07 g/mol). P°_ethanol = 50.0 torr at 25°C.

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?

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

Cinnamaldehyde ( = 132.15 g/mol) is used as a flavoring agent. What mass of cinnamaldehyde must be added to 175 g of ethanol to give a solution whose boiling point is 82.7°C? K_b = 1.22°C/m, boiling point of pure ethanol = 78.5°C