Question 1

Which of the following compounds will be most soluble in pentane (C5H12)?

Accepted Answer

A) pentanol (CH3CH2CH2CH2CH2OH) 
B) benzene (C6H6) 
C) acetic acid (CH3CO2H) 
D) ethyl methyl ketone (CH3CH2COCH3) 
E) None of these compounds should be soluble in pentane. 
A) pentanol (CH3CH2CH2CH2CH2OH) 
B) benzene (C6H6) 
C) acetic acid (CH3CO2H) 
D) ethyl methyl ketone (CH3CH2COCH3) 
E) None of these compounds should be soluble in pentane.

Question 2

Give the preparation of rock candy.

Accepted Answer

A saturated solution of sugar is prepare

Question 3

Calculate the volume of solution that has a vapour pressure of 25.8 mbar and contains 200.3 g of galactose, C6H12O6, at a temperature of 22.0 °C. The vapour pressure of pure water at 22 °C is 26.40 mbar, the density of water is 1.00 g mL-1, and assume no change in volume occurs upon dissolution.

Accepted Answer

A) 200 mL 
B) 91.3 mL 
C) 769 mL 
D) 862 mL 
E) 981 mL 
A) 200 mL 
B) 91.3 mL 
C) 769 mL 
D) 862 mL 
E) 981 mL

Question 4

Which of the following concentration units are temperature dependent?

Accepted Answer

A) mole fraction 
B) molality 
C) mass percent 
D) molarity 
E) None of the above 
A) mole fraction 
B) molality 
C) mass percent 
D) molarity 
E) None of the above

Question 5

Which of the following defines dissolving?

Accepted Answer

A) rate of dissolution = rate of deposition 
B) rate of dissolution  rate of deposition 
D) rate of bubbling > rate of dissolving 
E) rate of evaporating > rate of condensing 
A) rate of dissolution = rate of deposition 
B) rate of dissolution  rate of deposition 
D) rate of bubbling > rate of dissolving 
E) rate of evaporating > rate of condensing

Question 6

Calculate the molality of a solution formed by dissolving 27.8 g of LiI in 500.0 mL of water.

Accepted Answer

A) 0.254 mol kg-1 
B) 0.394 mol kg-1 
C) 0.556 mol kg-1 
D) 0.241 mol kg-1 
E) 0.415 mol kg-1 
A) 0.254 mol kg-1 
B) 0.394 mol kg-1 
C) 0.556 mol kg-1 
D) 0.241 mol kg-1 
E) 0.415 mol kg-1

Question 7

Place the following solutions in order of increasing osmotic pressure. I. 0.15 mol L-1 C2H6O2 II. 0.15 mol L-1 MgCl2 III. 0.15 mol L-1 NaCl

Accepted Answer

A) III < I < II 
B) II < III < I 
C) I < II < III 
D) II < I < III 
E) I < III < II 
A) III < I < II 
B) II < III < I 
C) I < II < III 
D) II < I < III 
E) I < III < II

Question 8

What is the weight percent of vitamin C in a solution made by dissolving 6.50 g of vitamin C, C6H8O6, in 55.0 g of water?

Accepted Answer

A) 0.547% 
B) 1.21% 
C) 10.6% 
D) 11.8% 
A) 0.547% 
B) 1.21% 
C) 10.6% 
D) 11.8%

Question 9

How many grams of KBr are required to make 350. mL of a 0.115 mol L-1 KBr solution?

Accepted Answer

A) 0.338 g 
B) 3.04 g 
C) 4.79 g 
D) 40.3 g 
A) 0.338 g 
B) 3.04 g 
C) 4.79 g 
D) 40.3 g

Question 10

Pentane (C5H12)is mixed with 75.8 g hexane (C6H14). Calculate the vapour pressure of the resulting solution. The vapour pressures of pure pentane and hexane are 425 Torr and 151 Torr, respectively. The total solution mass is 206.6 g. Assume ideal behaviour.

Accepted Answer

A) 335 Torr 
B) 368 Torr 
C) 263 Torr 
D) 360 Torr 
E) 294 Torr 
A) 335 Torr 
B) 368 Torr 
C) 263 Torr 
D) 360 Torr 
E) 294 Torr

Question 11

A KCl solution is prepared by dissolving 25.0 g KCl in 250.0 g of water at 25 °C. What is the vapour pressure of the solution if the vapour pressure of water at 25 °C is 23.76 mmHg?

Accepted Answer

A) 21.6 mmHg 
B) 22.7 mmHg 
C) 23.2 mmHg 
D) 24.9 mmHg 
A) 21.6 mmHg 
B) 22.7 mmHg 
C) 23.2 mmHg 
D) 24.9 mmHg

Question 12

An unknown nonelectrolyte and nonvolatile compound is dissolved in enough pure water to make 348 mL of solution. The vapour pressure above the solution drops from 198.7 mbar to 196.7 mbar when 100.0 g of the compound is dissolved at constant temperature. Determine the molar mass of the unknown compound. Assume no change in volume occurs upon dissolution.

Accepted Answer

A) 689 g mol-1 
B) 342 g mol-1 
C) 180 g mol-1 
D) 509 g mol-1 
E) 243 g mol-1 
A) 689 g mol-1 
B) 342 g mol-1 
C) 180 g mol-1 
D) 509 g mol-1 
E) 243 g mol-1

Question 13

Match the following.

-0.0050 mol kg-1 CO2

Accepted Answer

A) largest van't Hoff factor 
B) solution that is most strongly dependent upon pressure 
C) solution of ionic compound with highest freezing point. 
D) highest boiling point 
E) solution with ΔTb = 0.026 °C 
A) largest van't Hoff factor 
B) solution that is most strongly dependent upon pressure 
C) solution of ionic compound with highest freezing point. 
D) highest boiling point 
E) solution with ΔTb = 0.026 °C

Question 14

Why isn't pentanol (CH3CH2CH2CH2CH2OH)very soluble in water?

Accepted Answer

Even though the pentanol molecule contai

Question 15

Parts per billion requires a multiplication factor of ________.

Accepted Answer

A) 10-6 
B) 10-3 
C) 103 
D) 106 
E) 109 
A) 10-6 
B) 10-3 
C) 103 
D) 106 
E) 109

Question 16

Determine the molality of a solution prepared by dissolving 0.500 moles of CaF2 in 11.5 moles H2O.

Accepted Answer

A) 1.88 mol kg-1 
B) 4.35 mol kg-1 
C) 5.31 mol kg-1 
D) 4.14 mol kg-1 
E) 2.41 mol kg-1 
A) 1.88 mol kg-1 
B) 4.35 mol kg-1 
C) 5.31 mol kg-1 
D) 4.14 mol kg-1 
E) 2.41 mol kg-1

Question 17

Determine the freezing point depression of a solution that contains 30.7 g glycerin (C3H8O3, molar mass = 92.09 g mol-1)in 376 mL of water. Some possibly useful constants for water are Kf = 1.86 °C m-1 and Kb = 0.512 °C m-1.

Accepted Answer

A) 0.887 °C 
B) 1.65 °C 
C) 2.54 °C 
D) 3.33 °C 
E) 0.654 °C 
A) 0.887 °C 
B) 1.65 °C 
C) 2.54 °C 
D) 3.33 °C 
E) 0.654 °C

Question 18

Choose the aqueous solution that has the highest boiling point. These are all solutions of nonvolatile solutes and you should assume ideal van't Hoff factors where applicable.

Accepted Answer

A) 0.100 mol kg-1 AlCl3 
B) 0.100 mol kg-1 NaCl 
C) 0.100 mol kg-1 MgCl2 
D) 0.100 mol kg-1 C6H12O6 
E) They all have the same boiling point. 
A) 0.100 mol kg-1 AlCl3 
B) 0.100 mol kg-1 NaCl 
C) 0.100 mol kg-1 MgCl2 
D) 0.100 mol kg-1 C6H12O6 
E) They all have the same boiling point.

Question 19

A solution of methanol and water has a vapour pressure of 248 Torr. What would you predict as the mole fractions of each component, assuming ideal behaviour? The vapour pressures of methanol and water are 256 Torr and 55.3 Torr, respectively.

Accepted Answer

A)    = 0.990,   = 0.010 
B)    = 0.940,   = 0.060 
C)    = 0.960,   = 0.040 
D)    = 0.910,   = 0.090 
E)    = 0.900,   = 0.100 
A)    = 0.990,   = 0.010 
B)    = 0.940,   = 0.060 
C)    = 0.960,   = 0.040 
D)    = 0.910,   = 0.090 
E)    = 0.900,   = 0.100

Question 20

Commercial grade HCl solutions are typically 39.0% (by mass)HCl in water. Determine the molality of the HCl if the solution has a density of 1.20 g mL-1.

Accepted Answer

A) 39.0 mol kg-1 
B) 17.5 mol kg-1 
C) 6.39 mol kg-1 
D) 10.7 mol kg-1 
E) 9.44 mol kg-1 
A) 39.0 mol kg-1 
B) 17.5 mol kg-1 
C) 6.39 mol kg-1 
D) 10.7 mol kg-1 
E) 9.44 mol kg-1

Exam 12: Solutions

Which of the following compounds will be most soluble in pentane (C5H12)?

Give the preparation of rock candy.

Calculate the volume of solution that has a vapour pressure of 25.8 mbar and contains 200.3 g of galactose, C6H12O6, at a temperature of 22.0 °C. The vapour pressure of pure water at 22 °C is 26.40 mbar, the density of water is 1.00 g mL-1, and assume no change in volume occurs upon dissolution.

Which of the following concentration units are temperature dependent?

Which of the following defines dissolving?

Calculate the molality of a solution formed by dissolving 27.8 g of LiI in 500.0 mL of water.

Place the following solutions in order of increasing osmotic pressure. I. 0.15 mol L-1 C2H6O2 II. 0.15 mol L-1 MgCl2 III. 0.15 mol L-1 NaCl

What is the weight percent of vitamin C in a solution made by dissolving 6.50 g of vitamin C, C6H8O6, in 55.0 g of water?

How many grams of KBr are required to make 350. mL of a 0.115 mol L-1 KBr solution?

Pentane (C5H12)is mixed with 75.8 g hexane (C6H14). Calculate the vapour pressure of the resulting solution. The vapour pressures of pure pentane and hexane are 425 Torr and 151 Torr, respectively. The total solution mass is 206.6 g. Assume ideal behaviour.

A KCl solution is prepared by dissolving 25.0 g KCl in 250.0 g of water at 25 °C. What is the vapour pressure of the solution if the vapour pressure of water at 25 °C is 23.76 mmHg?

Match the following. -0.0050 mol kg-1 CO2

Why isn't pentanol (CH3CH2CH2CH2CH2OH)very soluble in water?

Parts per billion requires a multiplication factor of ________.

Determine the molality of a solution prepared by dissolving 0.500 moles of CaF2 in 11.5 moles H2O.

Determine the freezing point depression of a solution that contains 30.7 g glycerin (C3H8O3, molar mass = 92.09 g mol-1)in 376 mL of water. Some possibly useful constants for water are Kf = 1.86 °C m-1 and Kb = 0.512 °C m-1.

Choose the aqueous solution that has the highest boiling point. These are all solutions of nonvolatile solutes and you should assume ideal van't Hoff factors where applicable.

A solution of methanol and water has a vapour pressure of 248 Torr. What would you predict as the mole fractions of each component, assuming ideal behaviour? The vapour pressures of methanol and water are 256 Torr and 55.3 Torr, respectively.

Commercial grade HCl solutions are typically 39.0% (by mass)HCl in water. Determine the molality of the HCl if the solution has a density of 1.20 g mL-1.

Units of Measurement for Physical and Chemical Change

Atoms and Elements

Molecules, Compounds, and Nomenclature

Chemical Reactions and Stoichiometry

Gases

Thermochemistry

The Quantum-Mechanical Model of the Atom

Periodic Properties of the Elements

Chemical Bonding I: Lewis Theory

Chemical Bonding Ii: Molecular Shapes, Valence Bond Theory, and Molecular Orbital Theory

Liquids, Solids, and Intermolecular Forces

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

Aqueous Ionic Equilibrium

Gibbs Energy and Thermodynamics

Electrochemistry

Radioactivity and Nuclear Chemistry

Organic Chemistry I: Structures

Organic Chemistry II: Reactions

Biochemistry

Chemistry of the Nonmetals

Metals and Metallury

Transition Metals and Coordination Compounds

Filters

Which of the following compounds will be most soluble in pentane (C₅H₁₂)?

Place the following solutions in order of increasing osmotic pressure. I. 0.15 mol L^-1 C₂H₆O₂ II. 0.15 mol L^-1 MgCl₂ III. 0.15 mol L^-1 NaCl

What is the weight percent of vitamin C in a solution made by dissolving 6.50 g of vitamin C, C₆H₈O₆, in 55.0 g of water?

How many grams of KBr are required to make 350. mL of a 0.115 mol L^-1 KBr solution?

Pentane (C₅H₁₂)is mixed with 75.8 g hexane (C₆H₁₄). Calculate the vapour pressure of the resulting solution. The vapour pressures of pure pentane and hexane are 425 Torr and 151 Torr, respectively. The total solution mass is 206.6 g. Assume ideal behaviour.

Match the following. -0.0050 mol kg^-1 CO₂

Why isn't pentanol (CH₃CH₂CH₂CH₂CH₂OH)very soluble in water?

Determine the molality of a solution prepared by dissolving 0.500 moles of CaF₂ in 11.5 moles H₂O.

Determine the freezing point depression of a solution that contains 30.7 g glycerin (C₃H₈O₃, molar mass = 92.09 g mol^-1)in 376 mL of water. Some possibly useful constants for water are K_f = 1.86 °C m^-1 and K_b = 0.512 °C m^-1.

Commercial grade HCl solutions are typically 39.0% (by mass)HCl in water. Determine the molality of the HCl if the solution has a density of 1.20 g mL^-1.