Question 1

In a 0.1 molar solution of NaCl in water, which of the following will be closest to 0.1?

Accepted Answer

A)  the molality of NaCl 
B)  the mass percent of NaCl 
C)  the mole fraction of NaCl 
D)  the mass fraction of NaCl 
E)  All of these are about 0.1. 
A)  the molality of NaCl 
B)  the mass percent of NaCl 
C)  the mole fraction of NaCl 
D)  the mass fraction of NaCl 
E)  All of these are about 0.1.

Question 2

Thyroxine, an important hormone that controls the rate of metabolism in the body, can be isolated from the thyroid gland. If 0.455 g of thyroxine is dissolved in 10.0 g of benzene, the freezing point of the solution is 5.144°C. Pure benzene freezes at 5.444°C and has a value for the molal freezing-point-depression constant of Kf of 5.12°C/m. What is the molar mass of thyroxine?

Accepted Answer

A)  2330 g/mol 
B)  285 g/mol 
C)  777 g/mol 
D)  3760 g/mol 
E)  777,000 g/mol 
A)  2330 g/mol 
B)  285 g/mol 
C)  777 g/mol 
D)  3760 g/mol 
E)  777,000 g/mol

Question 3

Calculate the mole fraction of KCl in a solution prepared by dissolving 2.50 g of KCl in 500.0 g of H2O.

Accepted Answer

Question 4

The term proof is defined as twice the percent by volume of pure ethanol in solution. Thus, a solution that is 95% (by volume) ethanol is 190 proof. What is the molarity of ethanol in a 92 proof ethanol/water solution?

Accepted Answer

A)  0.46 M 
B)  0.80 M 
C)  17 M 
D)  0.92 M 
E)  8.0 M 
A)  0.46 M 
B)  0.80 M 
C)  17 M 
D)  0.92 M 
E)  8.0 M

Question 5

A chemist is given a white solid that is suspected of being pure cocaine (molar mass = 303.35 g/mol). When 1.22 g of the solid is dissolved in 15.60 g of benzene, the freezing point is lowered by 1.32°C. The molar mass is calculated from these data to be 303g. Assuming the following uncertainties, can the chemist be sure the substance is not codeine (molar mass 299.36)? Kf for benzene is 5.12°C/m.Uncertainties
Mass of solid = ±0.01 g
Mass of benzene = ±0.01 g
ΔT (freezing-point lowering) = ±0.04°C
Kf = ±0.01
Support your answer with calculations.

Accepted Answer

We want to find the minimum molar mass g

Question 6

To calculate the freezing point of an ideal dilute solution of a single, nondissociating solute in a solvent, the minimum information one must know is
I.the molality (of the solute).
II.the molality (of the solute) and the freezing-point-depression constant of the solvent.
III.the freezing point of the pure solvent.
IV.the molecular weight of the solute.
V.the weight of the solvent.

Accepted Answer

A)  II, III only 
B)  II only 
C)  II, III, IV 
D)  II, III, V 
E)  I only 
A)  II, III only 
B)  II only 
C)  II, III, IV 
D)  II, III, V 
E)  I only

Question 7

Which statement about hydrogen bonding is true?

Accepted Answer

A)  Hydrogen bonding arises from the dipole moment created by the unequal sharing of electrons in certain covalent bonds within a molecule. 
B)  Hydrogen bonding of solvent molecules with a solute will not affect the solubility of the solute. 
C)  The hydrogen-bonding capabilities of water molecules cause CH3CH2CH2CH3 to be more soluble in water than is CH3OH. 
D)  Hydrogen-bonding interactions between molecules are stronger than the covalent bonds within the molecule. 
E)  Hydrogen bonding is the intermolecular attractive forces between two hydrogen atoms in solution. 
A)  Hydrogen bonding arises from the dipole moment created by the unequal sharing of electrons in certain covalent bonds within a molecule. 
B)  Hydrogen bonding of solvent molecules with a solute will not affect the solubility of the solute. 
C)  The hydrogen-bonding capabilities of water molecules cause CH3CH2CH2CH3 to be more soluble in water than is CH3OH. 
D)  Hydrogen-bonding interactions between molecules are stronger than the covalent bonds within the molecule. 
E)  Hydrogen bonding is the intermolecular attractive forces between two hydrogen atoms in solution.

Question 8

When 0.020 mol of a weak acid HA is dissolved in enough water to make 1.0 L of solution, [H+] is 3.6 ×10-3 M. Calculate the freezing point of this solution. Assume that the molarity concentration is equal to the molality concentration, and assume ideal behavior. Kf (H2O) is 1.86°C kg/mol.

Accepted Answer

A)  -0.088°C 
B)  -0.044°C 
C)  -0.037°C 
D)  +0.044°C 
E)  +0.037°C 
A)  -0.088°C 
B)  -0.044°C 
C)  -0.037°C 
D)  +0.044°C 
E)  +0.037°C

Question 9

Calculate the osmotic pressure (in torr) of 5.88 L of an aqueous 0.144 M solution at 28°C if the solute concerned is totally ionized into three ions (for example, it could be Na2SO4 or MgCl2).

Accepted Answer

A)  8.11 × 103 torr 
B)  2.55 × 104 torr 
C)  2.70 × 103 torr 
D)  3.31 × 10-1 torr 
E)  7.55 × 102 torr 
A)  8.11 × 103 torr 
B)  2.55 × 104 torr 
C)  2.70 × 103 torr 
D)  3.31 × 10-1 torr 
E)  7.55 × 102 torr

Question 10

The flow of a solvent into its solution through a semipermeable membrane is called _____.

Accepted Answer

A)  ​osmosis 
B)  ​pyrolysis 
C)  ​hydrolysis 
D)  ​electrolysis 
E)  ​electrophoresis 
A)  ​osmosis 
B)  ​pyrolysis 
C)  ​hydrolysis 
D)  ​electrolysis 
E)  ​electrophoresis

Question 11

A 5.22-g sample of a compound is dissolved in 200.0 g of benzene. The freezing point of this solution is 1.08°C below that of pure benzene. What is the molar mass of this compound? (Note: Kf for benzene = 5.12°C/m.)

Accepted Answer

A)  1.24 × 102 g/mol 
B)  2.82 × 101 g/mol 
C)  1.82 × 102 g/mol 
D)  4.95 × 103 g/mol 
E)  5.51 × 102 g/mol 
A)  1.24 × 102 g/mol 
B)  2.82 × 101 g/mol 
C)  1.82 × 102 g/mol 
D)  4.95 × 103 g/mol 
E)  5.51 × 102 g/mol

Question 12

The phrase "a solid dissolved in a gas" describes a(n)

Accepted Answer

A)  aerosol. 
B)  emulsion. 
C)  foam. 
D)  sol. 
E)  none of these 
A)  aerosol. 
B)  emulsion. 
C)  foam. 
D)  sol. 
E)  none of these

Question 13

Rank the following compounds according to increasing solubility in water.
I.CH3-CH2-CH2-CH3

II.CH3-CH2-O-CH2-CH3

III. CH3-CH2-OH
IV. CH3-OH

Accepted Answer

A)  I < II < IV < III 
B)  I < III < IV < II 
C)  I < II < III < IV 
D)  III < IV < II < I 
E)  None is correct. 
A)  I < II < IV < III 
B)  I < III < IV < II 
C)  I < II < III < IV 
D)  III < IV < II < I 
E)  None is correct.

Question 14

Calculate the molarity of the solution made by dissolving 100.0 g of calcium nitrate in 450.0 mL of aqueous solution.

Accepted Answer

The answer of Calculate the molarity of the solution made...

Question 15

What is the mole percent of ethanol (C2H5OH) in the 180 proof vodka, which consists of 71.0 g of ethanol for every 10.0 g of water present?

Accepted Answer

A)  87.7% 
B)  71.0% 
C)  73.5% 
D)  26.5% 
E)  22.1% 
A)  87.7% 
B)  71.0% 
C)  73.5% 
D)  26.5% 
E)  22.1%

Question 16

You have at your disposal 3 1-pound bags of various pure salts that dissolve readily in water. You can add one of the bags to a 55 gallon barrel of water. Which bag should you use to lower the freezing point by the greatest amount? (1 lb. = 0.454 kg)

Accepted Answer

A)  Bag of KCl 
B)  Bag of MgCl2 
C)  Bag of Ba(NO3)2 
D)  Either B or C 
A)  Bag of KCl 
B)  Bag of MgCl2 
C)  Bag of Ba(NO3)2 
D)  Either B or C

Question 17

An aqueous solution contains 51.2 g of propanol (C3H7OH) in 123.0 g of solution. What is the mole fraction of propanol?

Accepted Answer

A)  0.176 
B)  ​0.294 
C)  ​0.272 
D)  ​0.214 
E)  ​0.824 
A)  0.176 
B)  ​0.294 
C)  ​0.272 
D)  ​0.214 
E)  ​0.824

Question 18

What is the boiling-point change for a solution containing 0.308 mol of naphthalene (a nonvolatile, nonionizing compound) in 266.0 g of liquid benzene? (Kb = 2.53°C/m for benzene)

Accepted Answer

A)  2.18°C 
B)  7.14°C 
C)  0.458°C 
D)  0.207°C 
E)  2.93°C 
A)  2.18°C 
B)  7.14°C 
C)  0.458°C 
D)  0.207°C 
E)  2.93°C

Question 19

What is the molality of an HCl solution made by dissolving 150.0 g of HCl in 450.0 g of water?

Accepted Answer

The answer of What is the molality of an HCl...

Question 20

A mixture of solid NaCl and CaCl2 contains 10.0 g of NaCl, and an unknown amount of CaCl2. When the entire mixture is dissolved in 1.00 kg of water, the boiling point changes by 0.25 °C. What mass of CaCl2 was in the original mixture?
Kb for water is 0.512 K. kg . mol-1.

Accepted Answer

A)  5.4 g 
B)  8.1 g 
C)  35.2 g 
D)  Not enough data to answer the question 
E)  None of the above 
A)  5.4 g 
B)  8.1 g 
C)  35.2 g 
D)  Not enough data to answer the question 
E)  None of the above

In a 0.1 molar solution of NaCl in water, which of the following will be closest to 0.1?

Calculate the mole fraction of KCl in a solution prepared by dissolving 2.50 g of KCl in 500.0 g of H₂O.

The term proof is defined as twice the percent by volume of pure ethanol in solution. Thus, a solution that is 95% (by volume) ethanol is 190 proof. What is the molarity of ethanol in a 92 proof ethanol/water solution?

Which statement about hydrogen bonding is true?

When 0.020 mol of a weak acid HA is dissolved in enough water to make 1.0 L of solution, [H⁺] is 3.6 ×10^-3 M. Calculate the freezing point of this solution. Assume that the molarity concentration is equal to the molality concentration, and assume ideal behavior. K_f (H₂O) is 1.86°C kg/mol.

Calculate the osmotic pressure (in torr) of 5.88 L of an aqueous 0.144 M solution at 28°C if the solute concerned is totally ionized into three ions (for example, it could be Na₂SO₄ or MgCl₂).

The flow of a solvent into its solution through a semipermeable membrane is called _____.

A 5.22-g sample of a compound is dissolved in 200.0 g of benzene. The freezing point of this solution is 1.08°C below that of pure benzene. What is the molar mass of this compound? (Note: K_f for benzene = 5.12°C/m.)

The phrase "a solid dissolved in a gas" describes a(n)

Rank the following compounds according to increasing solubility in water. I.CH₃-CH₂-CH₂-CH₃ II.CH₃-CH₂-O-CH₂-CH₃ III. CH₃-CH₂-OH IV. CH₃-OH

Calculate the molarity of the solution made by dissolving 100.0 g of calcium nitrate in 450.0 mL of aqueous solution.

What is the mole percent of ethanol (C₂H₅OH) in the 180 proof vodka, which consists of 71.0 g of ethanol for every 10.0 g of water present?

You have at your disposal 3 1-pound bags of various pure salts that dissolve readily in water. You can add one of the bags to a 55 gallon barrel of water. Which bag should you use to lower the freezing point by the greatest amount? (1 lb. = 0.454 kg)

An aqueous solution contains 51.2 g of propanol (C₃H₇OH) in 123.0 g of solution. What is the mole fraction of propanol?

What is the boiling-point change for a solution containing 0.308 mol of naphthalene (a nonvolatile, nonionizing compound) in 266.0 g of liquid benzene? (K_b = 2.53°C/m for benzene)

What is the molality of an HCl solution made by dissolving 150.0 g of HCl in 450.0 g of water?

A mixture of solid NaCl and CaCl₂ contains 10.0 g of NaCl, and an unknown amount of CaCl₂. When the entire mixture is dissolved in 1.00 kg of water, the boiling point changes by 0.25 °C. What mass of CaCl₂ was in the original mixture? K_b for water is 0.512 K^. kg ^. mol^-1.

Atoms, Molecules, and Ions

Stoichiometry

Types of Chemical Reactions and Solution Stoichiometry

Gases

Chemical Equilibrium

Acids and Bases

Applications of Aqueous Equilibria

Energy, Enthalpy, and Thermochemistry

Spontaneity, Entropy, and Free Energy

Electrochemistry

Quantum Mechanics and Atomic Theory

Bonding: General Concepts

Covalent Bonding: Orbitals

Chemical Kinetics

Liquids and Solids

The Representative Elements

Transition Metals and Coordination Chemistry

The Nucleus: a Chemists View

Organic and Biochemical Molecules

Filters

Exam 17: Properties of Solutions

In a 0.1 molar solution of NaCl in water, which of the following will be closest to 0.1?

Calculate the mole fraction of KCl in a solution prepared by dissolving 2.50 g of KCl in 500.0 g of H2O.

The term proof is defined as twice the percent by volume of pure ethanol in solution. Thus, a solution that is 95% (by volume) ethanol is 190 proof. What is the molarity of ethanol in a 92 proof ethanol/water solution?

Which statement about hydrogen bonding is true?

When 0.020 mol of a weak acid HA is dissolved in enough water to make 1.0 L of solution, [H+] is 3.6 ×10-3 M. Calculate the freezing point of this solution. Assume that the molarity concentration is equal to the molality concentration, and assume ideal behavior. Kf (H2O) is 1.86°C kg/mol.

Calculate the osmotic pressure (in torr) of 5.88 L of an aqueous 0.144 M solution at 28°C if the solute concerned is totally ionized into three ions (for example, it could be Na2SO4 or MgCl2).

The flow of a solvent into its solution through a semipermeable membrane is called _____.

A 5.22-g sample of a compound is dissolved in 200.0 g of benzene. The freezing point of this solution is 1.08°C below that of pure benzene. What is the molar mass of this compound? (Note: Kf for benzene = 5.12°C/m.)

The phrase "a solid dissolved in a gas" describes a(n)

Rank the following compounds according to increasing solubility in water. I.CH3-CH2-CH2-CH3 II.CH3-CH2-O-CH2-CH3 III. CH3-CH2-OH IV. CH3-OH

Calculate the molarity of the solution made by dissolving 100.0 g of calcium nitrate in 450.0 mL of aqueous solution.

What is the mole percent of ethanol (C2H5OH) in the 180 proof vodka, which consists of 71.0 g of ethanol for every 10.0 g of water present?

You have at your disposal 3 1-pound bags of various pure salts that dissolve readily in water. You can add one of the bags to a 55 gallon barrel of water. Which bag should you use to lower the freezing point by the greatest amount? (1 lb. = 0.454 kg)

An aqueous solution contains 51.2 g of propanol (C3H7OH) in 123.0 g of solution. What is the mole fraction of propanol?

What is the boiling-point change for a solution containing 0.308 mol of naphthalene (a nonvolatile, nonionizing compound) in 266.0 g of liquid benzene? (Kb = 2.53°C/m for benzene)

What is the molality of an HCl solution made by dissolving 150.0 g of HCl in 450.0 g of water?

A mixture of solid NaCl and CaCl2 contains 10.0 g of NaCl, and an unknown amount of CaCl2. When the entire mixture is dissolved in 1.00 kg of water, the boiling point changes by 0.25 °C. What mass of CaCl2 was in the original mixture? Kb for water is 0.512 K. kg . mol-1.

Atoms, Molecules, and Ions

Stoichiometry

Types of Chemical Reactions and Solution Stoichiometry

Gases

Chemical Equilibrium

Acids and Bases

Applications of Aqueous Equilibria

Energy, Enthalpy, and Thermochemistry

Spontaneity, Entropy, and Free Energy

Electrochemistry

Quantum Mechanics and Atomic Theory

Bonding: General Concepts

Covalent Bonding: Orbitals

Chemical Kinetics

Liquids and Solids

The Representative Elements

Transition Metals and Coordination Chemistry

The Nucleus: a Chemists View

Organic and Biochemical Molecules

Filters

Calculate the mole fraction of KCl in a solution prepared by dissolving 2.50 g of KCl in 500.0 g of H₂O.

When 0.020 mol of a weak acid HA is dissolved in enough water to make 1.0 L of solution, [H⁺] is 3.6 ×10^-3 M. Calculate the freezing point of this solution. Assume that the molarity concentration is equal to the molality concentration, and assume ideal behavior. K_f (H₂O) is 1.86°C kg/mol.

Calculate the osmotic pressure (in torr) of 5.88 L of an aqueous 0.144 M solution at 28°C if the solute concerned is totally ionized into three ions (for example, it could be Na₂SO₄ or MgCl₂).

A 5.22-g sample of a compound is dissolved in 200.0 g of benzene. The freezing point of this solution is 1.08°C below that of pure benzene. What is the molar mass of this compound? (Note: K_f for benzene = 5.12°C/m.)

Rank the following compounds according to increasing solubility in water. I.CH₃-CH₂-CH₂-CH₃ II.CH₃-CH₂-O-CH₂-CH₃ III. CH₃-CH₂-OH IV. CH₃-OH

What is the mole percent of ethanol (C₂H₅OH) in the 180 proof vodka, which consists of 71.0 g of ethanol for every 10.0 g of water present?

An aqueous solution contains 51.2 g of propanol (C₃H₇OH) in 123.0 g of solution. What is the mole fraction of propanol?

What is the boiling-point change for a solution containing 0.308 mol of naphthalene (a nonvolatile, nonionizing compound) in 266.0 g of liquid benzene? (K_b = 2.53°C/m for benzene)

A mixture of solid NaCl and CaCl₂ contains 10.0 g of NaCl, and an unknown amount of CaCl₂. When the entire mixture is dissolved in 1.00 kg of water, the boiling point changes by 0.25 °C. What mass of CaCl₂ was in the original mixture? K_b for water is 0.512 K^. kg ^. mol^-1.