Question 1

Which of the following statements describes the correct method of preparation of 1.00 L of a 2.0 M urea solution?   urea = 60.06 g/mol

Accepted Answer

A)  Dissolve 120 g of urea in 1.00 kg of distilled water. 
B)  Dissolve 120 g of urea in 880 g of distilled water. 
C)  Dissolve 120 g of urea in enough distilled water to produce 1.00 L of solution. 
D)  Dissolve 120 g of urea in 1.00 liter of distilled water. 
E)  The density of urea is needed in order to do this calculation. 
A)  Dissolve 120 g of urea in 1.00 kg of distilled water. 
B)  Dissolve 120 g of urea in 880 g of distilled water. 
C)  Dissolve 120 g of urea in enough distilled water to produce 1.00 L of solution. 
D)  Dissolve 120 g of urea in 1.00 liter of distilled water. 
E)  The density of urea is needed in order to do this calculation.

Question 2

Raoult's Law relates the vapor pressure of a solvent above a solution to the mole fraction of the solvent and the vapor pressure of the pure solvent.

Accepted Answer

A) True 
 B)False

Question 3

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 4

If a 100-mL sample of a volatile liquid such as diethyl ether is introduced into a 250-mL flask which is immediately sealed, the pressure inside will increase above atmospheric pressure. Explain.

Accepted Answer

The pressure inside the flask will initi

Question 5

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 6

Select the weakest electrolyte from the following set.

Accepted Answer

A)  Na2SO4 
B)  KCl 
C)  CH3CH2COOH, propionic acid 
D)  CaCl2 
E)  LiOH 
A)  Na2SO4 
B)  KCl 
C)  CH3CH2COOH, propionic acid 
D)  CaCl2 
E)  LiOH

Question 7

Calcium nitrite is used as a corrosion inhibitor in lubricants. What is the molality of a solution prepared by dissolving 18.5 g of calcium nitrite in 83.5 g of distilled water?

Accepted Answer

A)  0.0342 m 
B)  0.0855 m 
C)  0.222 m 
D)  0.444 m 
E)  1.68 m 
A)  0.0342 m 
B)  0.0855 m 
C)  0.222 m 
D)  0.444 m 
E)  1.68 m

Question 8

Cadmium bromide is used in photography and lithography. Calculate the molality of a solution prepared by dissolving 45.38 g of CdBr2 in 375.0 g of water.

Accepted Answer

A)  0.03035 m 
B)  0.01600 m 
C)  0.1210 m 
D)  0.4446 m 
E)  none of the above 
A)  0.03035 m 
B)  0.01600 m 
C)  0.1210 m 
D)  0.4446 m 
E)  none of the above

Question 9

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 10

Which, if any, of the following features is common to soaps, detergents, phospholipids, and channel-forming antibiotics?

Accepted Answer

A)  They all contain fatty acids. 
B)  They all contain phosphate groups. 
C)  They all contain polypeptide chains. 
D)  Their function depends on the dual polarity of their molecules. 
E)  They have none of the above features in common. 
A)  They all contain fatty acids. 
B)  They all contain phosphate groups. 
C)  They all contain polypeptide chains. 
D)  Their function depends on the dual polarity of their molecules. 
E)  They have none of the above features in common.

Question 11

Helical segments of protein molecules arise through hydrogen bonding between C=O and N-H groups.

Accepted Answer

A) True 
 B)False

Question 12

Based only on the relative lattice energies of the compounds below, which one would be expected to have the lowest solubility in water?

Accepted Answer

A)  NaBr 
B)  CaS 
C)  NaOH 
D)  KI 
E)  CsCl 
A)  NaBr 
B)  CaS 
C)  NaOH 
D)  KI 
E)  CsCl

Question 13

The density of pure water at 25°C is 0.997 g/mL. Considering water as being both solvent and solute, calculate its molarity.

Accepted Answer

The answer of The density of pure water at 25°C...

Question 14

The backbone of a protein chain consists of carbon, nitrogen, and oxygen atoms.

Accepted Answer

A) True 
 B)False

Question 15

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 16

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 the above statements is true. 
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 the above statements is true.

Question 17

Heats of solution may be either positive or negative.

Accepted Answer

A) True 
 B)False

Question 18

Dimethylglyoxime, DMG, is an organic compound used to test for aqueous nickel(II) ions. A solution prepared by dissolving 65.0 g of DMG in 375 g of ethanol boils at 80.3°C. What is the molar mass of DMG? Kb = 1.22°C/m, boiling point of pure ethanol = 78.5°C

Accepted Answer

A)  44.1 g/mol 
B)  65.8 g/mol 
C)  117 g/mol 
D)  131.6 g/mol 
E)  553 g/mol 
A)  44.1 g/mol 
B)  65.8 g/mol 
C)  117 g/mol 
D)  131.6 g/mol 
E)  553 g/mol

Question 19

Colloidal particles may be either solids, liquids, or gases.

Accepted Answer

A) True 
 B)False

Question 20

Which of the following aqueous liquids will have the lowest freezing point?

Accepted Answer

A)  0.5 m C12H22O11 (sucrose) 
B)  0.5 m Ca(NO3)2 
C)  0.5 m NiSO4 
D)  0.5 m Li3PO4 
E)  pure water 
A)  0.5 m C12H22O11 (sucrose) 
B)  0.5 m Ca(NO3)2 
C)  0.5 m NiSO4 
D)  0.5 m Li3PO4 
E)  pure water

Exam 13: The Properties of Mixtures: Solutions and Colloids

Which of the following statements describes the correct method of preparation of 1.00 L of a 2.0 M urea solution? urea = 60.06 g/mol

Raoult's Law relates the vapor pressure of a solvent above a solution to the mole fraction of the solvent and the vapor pressure of the pure solvent.

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.

If a 100-mL sample of a volatile liquid such as diethyl ether is introduced into a 250-mL flask which is immediately sealed, the pressure inside will increase above atmospheric pressure. Explain.

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.)

Select the weakest electrolyte from the following set.

Calcium nitrite is used as a corrosion inhibitor in lubricants. What is the molality of a solution prepared by dissolving 18.5 g of calcium nitrite in 83.5 g of distilled water?

Cadmium bromide is used in photography and lithography. Calculate the molality of a solution prepared by dissolving 45.38 g of CdBr2 in 375.0 g of water.

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?

Which, if any, of the following features is common to soaps, detergents, phospholipids, and channel-forming antibiotics?

Helical segments of protein molecules arise through hydrogen bonding between C=O and N-H groups.

Based only on the relative lattice energies of the compounds below, which one would be expected to have the lowest solubility in water?

The density of pure water at 25°C is 0.997 g/mL. Considering water as being both solvent and solute, calculate its molarity.

The backbone of a protein chain consists of carbon, nitrogen, and oxygen atoms.

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?

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

Heats of solution may be either positive or negative.

Dimethylglyoxime, DMG, is an organic compound used to test for aqueous nickel(II) ions. A solution prepared by dissolving 65.0 g of DMG in 375 g of ethanol boils at 80.3°C. What is the molar mass of DMG? Kb = 1.22°C/m, boiling point of pure ethanol = 78.5°C

Colloidal particles may be either solids, liquids, or gases.

Which of the following aqueous liquids will have the lowest freezing point?

Keys to the Study of Chemistry

The Components of Matter

Stoichiometry of Formulas and Equations

The 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: Bonding, Structure, and Reactivity

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 the Direction of Chemical Reactions

Electrochemistry: Chemical Change and Electrical Work

The Elements in Nature and Industry

The Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

Which of the following statements describes the correct method of preparation of 1.00 L of a 2.0 M urea solution? _urea = 60.06 g/mol

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.

Cadmium bromide is used in photography and lithography. Calculate the molality of a solution prepared by dissolving 45.38 g of CdBr₂in 375.0 g of water.

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 CH₄will dissolve in 3.00 L of benzene if the partial pressure of CH₄is 1.48 atm?

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

Dimethylglyoxime, DMG, is an organic compound used to test for aqueous nickel(II) ions. A solution prepared by dissolving 65.0 g of DMG in 375 g of ethanol boils at 80.3°C. What is the molar mass of DMG? K_b = 1.22°C/m, boiling point of pure ethanol = 78.5°C