Question 1

What is the weight percent of a caffeine solution made by dissolving 8.35 g of caffeine,C8H10N4O2,in 75 g of benzene,C6H6?

Accepted Answer

A) 0)0 10% 
B) 0)0 11% 
C) 10% 
D) 11% 
A) 0)0 10% 
B) 0)0 11% 
C) 10% 
D) 11%

Question 2

At 25°C the vapor pressures of benzene and toluene are 96.0 mm Hg and 30.5 mm Hg,respectively.When a 1:1 molar mixture of benzene and toluene is fractionally distilled,the first fraction will have a mole fraction of benzene that is closest to

Accepted Answer

A) 0)0 
B) 0)5 
C) 0)7 
D) 1)0 
A) 0)0 
B) 0)5 
C) 0)7 
D) 1)0

Question 3

Which of the following solutions will have the lowest freezing point?

Accepted Answer

A) 0)0100 m NaCl 
B) 0)0100 m Li2SO4 
C) 0)035 m CH3CH2CH2OH 
D) 0)015 m MgCl2 
A) 0)0100 m NaCl 
B) 0)0100 m Li2SO4 
C) 0)035 m CH3CH2CH2OH 
D) 0)015 m MgCl2

Question 4

The rubbing alcohol sold in drug stores often is composed of 70% isopropyl alcohol and 30% water.In this solution

Accepted Answer

A) isopropyl alcohol is the solvent. 
B) water is the solvent. 
C) both water and isopropyl alcohol are solvents. 
D) neither water nor isopropyl alcohol is a solvent. 
A) isopropyl alcohol is the solvent. 
B) water is the solvent. 
C) both water and isopropyl alcohol are solvents. 
D) neither water nor isopropyl alcohol is a solvent.

Question 5

What is the mole fraction of oxygen in a gas mixture that is 37% oxygen and 63% nitrogen by volume?

Accepted Answer

A) 0)34 
B) 0)37 
C) 0)25 
D) 0)52 
A) 0)34 
B) 0)37 
C) 0)25 
D) 0)52

Question 6

A 3.17 m solution of CaCl2 in water has a density of 1.24 g/mL.What is the molarity?

Accepted Answer

A) 2)56 M CaCl2 
B) 2)91 M CaCl2 
C) 3)50 M CaCl2 
D) 3)93 M CaCl2 
A) 2)56 M CaCl2 
B) 2)91 M CaCl2 
C) 3)50 M CaCl2 
D) 3)93 M CaCl2

Question 7

To make a 2.00 m solution,one could take 2.00 moles of solute and add

Accepted Answer

A) 1)00 L of solvent. 
B) 1)00 kg of solvent. 
C) enough solvent to make 1.00 L of solution. 
D) enough solvent to make 1.00 kg of solution. 
A) 1)00 L of solvent. 
B) 1)00 kg of solvent. 
C) enough solvent to make 1.00 L of solution. 
D) enough solvent to make 1.00 kg of solution.

Question 8

At 25.0°C,a solution has a concentration of 3.179 M and a density of 1.260 g/mL.The density of the solution at 50.0°C is 1.249 g/mL.What is the molarity of the solution at 50.0°C?

Accepted Answer

A) 2)545 M 
B) 3)151 M 
C) 3)179 M 
D) 3)230 M 
A) 2)545 M 
B) 3)151 M 
C) 3)179 M 
D) 3)230 M

Question 9

A KCl solution is prepared by dissolving 20.0 g KCl in 250.0 g of water at 25°C.What is the vapor pressure of the solution if the vapor pressure of water at 25°C is 23.76 mm Hg?

Accepted Answer

A) 22.0 mm Hg 
B) 22.9 mm Hg 
C) 23.3 mm Hg 
D) 24.6 mm Hg 
A) 22.0 mm Hg 
B) 22.9 mm Hg 
C) 23.3 mm Hg 
D) 24.6 mm Hg

Question 10

The coolant in automobiles is often a 50/50 % by volume mixture of ethylene glycol,HOCH2CH2OH,and water.At 20°C,the density of ethylene glycol is 1.1088 g/mL and the density of water is 0.9982 g/mL.Assuming that the volumes are additive,what is the expected freezing point of a 50/50(v/v)% ethylene glycol/water solution? Kf = 1.86°C/m for water.

Accepted Answer

A) -16°C 
B) -17°C 
C) -30°C 
D) -33°C 
A) -16°C 
B) -17°C 
C) -30°C 
D) -33°C

Question 11

A solution is prepared by dissolving 40.0 g of sucrose,C12H22O11,in 250.g of water at 25°C.What is the vapor pressure of the solution if the vapor pressure of water at 25°C is 23.76 mm Hg?

Accepted Answer

A) 0)198 mm Hg 
B) 20.5 mm Hg 
C) 23.6 mm Hg 
D) 24.0 mm Hg 
A) 0)198 mm Hg 
B) 20.5 mm Hg 
C) 23.6 mm Hg 
D) 24.0 mm Hg

Question 12

At 80.0°C benzene has a vapor pressure of 96.0 mm Hg and toluene has a vapor pressure of 30.3 mm Hg.If a mixture of benzene and toluene has a vapor pressure of 54.6 mm Hg,what are the mole fractions of benzene and toluene?

Accepted Answer

The answer of At 80.0°C benzene has a vapor pressure...

Question 13

A phase diagram of temperature versus composition for a mixture of the two volatile liquids octane (bp = 69°C)and decane (bp = 126°C)is shown.  
-Assume that the vapor at point c is condensed and reboiled.What is the vapor composition during reboiling?

Accepted Answer

A) 100% decane 
B) composition at point b 
C) composition at point c 
D) composition at point e 
A) 100% decane 
B) composition at point b 
C) composition at point c 
D) composition at point e

Question 14

What is the mole fraction of oxygen in a gas mixture that is 22% oxygen and 78% nitrogen by volume?

Accepted Answer

A) 0)20 
B) 0)22 
C) 0)25 
D) 0)28 
A) 0)20 
B) 0)22 
C) 0)25 
D) 0)28

Question 15

Molality is defined as moles of solute per

Accepted Answer

A) kilogram of solvent. 
B) liter of solution. 
C) mole of solvent. 
D) total moles present. 
A) kilogram of solvent. 
B) liter of solution. 
C) mole of solvent. 
D) total moles present.

Question 16

Arrows in the energy diagram below represent enthalpy changes occurring in the endothermic formation of a solution:
ΔHS1U1B1solnS1U1B0 = enthalpy of solution
ΔHS1U1B1solute-soluteS1U1B0 = enthalpy change involving solute-solute interactions
ΔHS1U1B1solute-solventS1U1B0 = enthalpy change involving solute-solvent interactions
ΔHS1U1B1solvent-solventS1U1B0 = enthalpy change involving solvent-solvent interactions  
-Which arrow represents ΔHsolute-solvent?

Accepted Answer

A) arrow (a) 
B) arrow (b) 
C) arrow (c) 
D) arrow (d) 
A) arrow (a) 
B) arrow (b) 
C) arrow (c) 
D) arrow (d)

Question 17

The solubility of a gas in a liquid is greatest at ________ pressures and ________ temperatures.

Accepted Answer

The answer of The solubility of a gas in a...

Question 18

What molality of pentane is obtained by dissolving 15 g pentane,C5H12,in 245.0 g hexane,C6H14?

Accepted Answer

A) 0)0 58 m 
B) 0)068 m 
C) 0)85 m 
D) 61 m 
A) 0)0 58 m 
B) 0)068 m 
C) 0)85 m 
D) 61 m

Question 19

What are the major solute-solvent interactions created when KBr dissolves in water?

Accepted Answer

A) dipole-dipole 
B) dispersion 
C) hydrogen bonding 
D) ion-dipole 
A) dipole-dipole 
B) dispersion 
C) hydrogen bonding 
D) ion-dipole

Question 20

The following diagram shows a close-up view of the vapor pressure curves for a pure solvent and a solution containing a nonvolatile solute dissolved in this solvent.  
-Which curve is the solvent and what happens to the vapor pressure when the solute is dissolved in the solvent?

Accepted Answer

A) Curve (a)is the solvent and the vapor pressure decreases. 
B) Curve (a)is the solvent and the vapor pressure increases. 
C) Curve (b)is the solvent and the vapor pressure decreases. 
D) Curve (b)is the solvent and the vapor pressure increases. 
A) Curve (a)is the solvent and the vapor pressure decreases. 
B) Curve (a)is the solvent and the vapor pressure increases. 
C) Curve (b)is the solvent and the vapor pressure decreases. 
D) Curve (b)is the solvent and the vapor pressure increases.

Exam 11: Solutions and Their Properties

What is the weight percent of a caffeine solution made by dissolving 8.35 g of caffeine,C8H10N4O2,in 75 g of benzene,C6H6?

At 25°C the vapor pressures of benzene and toluene are 96.0 mm Hg and 30.5 mm Hg,respectively.When a 1:1 molar mixture of benzene and toluene is fractionally distilled,the first fraction will have a mole fraction of benzene that is closest to

Which of the following solutions will have the lowest freezing point?

The rubbing alcohol sold in drug stores often is composed of 70% isopropyl alcohol and 30% water.In this solution

What is the mole fraction of oxygen in a gas mixture that is 37% oxygen and 63% nitrogen by volume?

A 3.17 m solution of CaCl2 in water has a density of 1.24 g/mL.What is the molarity?

To make a 2.00 m solution,one could take 2.00 moles of solute and add

At 25.0°C,a solution has a concentration of 3.179 M and a density of 1.260 g/mL.The density of the solution at 50.0°C is 1.249 g/mL.What is the molarity of the solution at 50.0°C?

A KCl solution is prepared by dissolving 20.0 g KCl in 250.0 g of water at 25°C.What is the vapor pressure of the solution if the vapor pressure of water at 25°C is 23.76 mm Hg?

A solution is prepared by dissolving 40.0 g of sucrose,C12H22O11,in 250.g of water at 25°C.What is the vapor pressure of the solution if the vapor pressure of water at 25°C is 23.76 mm Hg?

At 80.0°C benzene has a vapor pressure of 96.0 mm Hg and toluene has a vapor pressure of 30.3 mm Hg.If a mixture of benzene and toluene has a vapor pressure of 54.6 mm Hg,what are the mole fractions of benzene and toluene?

A phase diagram of temperature versus composition for a mixture of the two volatile liquids octane (bp = 69°C)and decane (bp = 126°C)is shown. -Assume that the vapor at point c is condensed and reboiled.What is the vapor composition during reboiling?

What is the mole fraction of oxygen in a gas mixture that is 22% oxygen and 78% nitrogen by volume?

Molality is defined as moles of solute per

The solubility of a gas in a liquid is greatest at ________ pressures and ________ temperatures.

What molality of pentane is obtained by dissolving 15 g pentane,C5H12,in 245.0 g hexane,C6H14?

What are the major solute-solvent interactions created when KBr dissolves in water?

The following diagram shows a close-up view of the vapor pressure curves for a pure solvent and a solution containing a nonvolatile solute dissolved in this solvent. -Which curve is the solvent and what happens to the vapor pressure when the solute is dissolved in the solvent?

Chemistry: Matter and Measurement

Atoms, molecules, and Ions

Formulas, equations, and Moles

Reactions in Aqueous Solutions

Periodicity and the Atomic Structure of Atoms

Ionic Bonds and Some Main-Group Chemistry

Covalent Bonds and Molecular Structure

Thermochemistry: Chemical Energy

Gases: Their Properties and Behavior

Liquids,solids,and Phase Changes

Chemical Kinetics

Chemical Equilibrium

Aqueous Equilibria: Acids and Bases

Applications of Aqueous Equilibria

Thermodynamics: Entropy, free Energy, and Equilibrium

Electrochemistry

Hydrogen, oxygen, and Water

The Main-Group Elements

Transition Elements and Coordination Chemistry

Metals and Solid-State Materials

Nuclear Chemistry

Organic and Biological Chemistry

Filters

What is the weight percent of a caffeine solution made by dissolving 8.35 g of caffeine,C₈H₁₀N₄O₂,in 75 g of benzene,C₆H₆?

A 3.17 m solution of CaCl₂ in water has a density of 1.24 g/mL.What is the molarity?

A solution is prepared by dissolving 40.0 g of sucrose,C₁₂H₂₂O₁₁,in 250.g of water at 25°C.What is the vapor pressure of the solution if the vapor pressure of water at 25°C is 23.76 mm Hg?

The solubility of a gas in a liquid is greatest at pressures and temperatures.

What molality of pentane is obtained by dissolving 15 g pentane,C₅H₁₂,in 245.0 g hexane,C₆H₁₄?