Question 1

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 2

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?

Accepted Answer

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

Question 3

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 4

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

Accepted Answer

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. 
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.

Question 5

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

Question 6

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?

Accepted Answer

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

Question 7

If a solute dissolves in an endothermic process

Accepted Answer

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. 
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 8

Under physiological conditions, amino acids in solution carry

Accepted Answer

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. 
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 9

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

Accepted Answer

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

Question 10

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 11

Hexachlorophene is used as a disinfectant in germicidal soaps. What mass of hexachlorophene (ℳ = 406.9 g/mol) must be added to 125 g of chloroform to give a solution with a boiling point of 62.60°C? Kb = 3.63°C/m, boiling point of pure chloroform = 61.70°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 12

A 0.100 m MgSO4 solution has a freezing point of −0.23°C. What is the van't Hoff factor for this solution? Kf = 1.86°C/m

Accepted Answer

A) 0.62 
B) 1.0 
C) 1.2 
D) 2.0 
E) 4.0 
A) 0.62 
B) 1.0 
C) 1.2 
D) 2.0 
E) 4.0

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

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 CaSO 4 
D) 0.05 m BaCl 2 
E) 0.10 m K 2SO 4 
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 15

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

Accepted Answer

A) Na + 
B) Cs + 
C) Ca 2+ 
D) F − 
E) I − 
A) Na + 
B) Cs + 
C) Ca 2+ 
D) F − 
E) I −

Question 16

Barbiturates are synthetic drugs used as sedatives and hypnotics. Barbital (ℳ = 184.2 g/mol) is one of the simplest of these drugs. What is the boiling point of a solution prepared by dissolving 42.5 g of barbital in 825 g of acetic acid? Kb = 3.07°C/m; boiling point of pure acetic acid = 117.9°C

Accepted Answer

A) 117.0°C 
B) 117.7°C 
C) 118.1°C 
D) 118.8°C 
E) >120°C 
A) 117.0°C 
B) 117.7°C 
C) 118.1°C 
D) 118.8°C 
E) >120°C

Question 17

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.

Accepted Answer

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

Question 18

Ideal solutions do not conform to Raoult's Law.

Accepted Answer

A) True 
 B)False

Question 19

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 20

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

Accepted Answer

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 
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

Exam 13: The Properties of Mixtures: Solutions and Colloids

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

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?

The Tyndall effect

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

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.

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?

If a solute dissolves in an endothermic process

Under physiological conditions, amino acids in solution carry

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

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?

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

A 0.100 m MgSO4 solution has a freezing point of −0.23°C. What is the van't Hoff factor for this solution? Kf = 1.86°C/m

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?

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

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

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.

Ideal solutions do not conform to Raoult's Law.

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.)

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

Keys to the Study of 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

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

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

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

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

A 0.100 m MgSO₄ solution has a freezing point of −0.23°C. What is the van't Hoff factor for this solution? K_f = 1.86°C/m

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