Deck 9: Molecules and Ions in Solution

Question 1

Select the true statement.

A) All vitamins are water-soluble.
B) All vitamins are fat-soluble.
C) Vitamins do not dissolve in either water or fat.
D) Some vitamins dissolve in water; others dissolve in fat.

Answer 1

D

Question 2

Select the correct statement about an aqueous solution.

A) It is a heterogeneous mixture.
B) Water is the solute.
C) Water is the solvent.
D) The solvent can be any substance.

Answer 2

C

Question 3

Forcing methane into water using pressure causes which of the following?

A) hydrogen bonding between methane and water
B) attraction of methane to water by dispersion forces
C) an increase in entropy since the water forms cage-like clathrates
D) the formation of water ice

Answer 3

C

Question 4

Select the true statement about hydrophobic molecules.

A) They are nonpolar.
B) They always contain carbon atoms
C) They are polar.
D) They may form hydrogen bonds with other molecules.

Question 5

Which of the following would be expected to be soluble in water?

A) CH₃CH₃
B) CH₂CH₂
C) CH₃CH₂OH
D) CH₃CH₂OCH₂CH₂CH₃

Question 6

Why is methanol, CH₃OH, soluble in water?

A) It interacts with water using dispersion forces.
B) It has an -OH group that can hydrogen bond with water.
C) It is small and can fit between water molecules.
D) It forms ions when dissolved in water that interact strongly with water.

Question 7

Complete the following sentence: The dispersion forces

A) become weaker as the molecule gets larger.
B) become stronger as the molecule gets larger.
C) are equal for all molecules regardless of size.
D) cannot be predicted from the size of the molecule.

Question 8

What is the dominant attractive force between nonpolar molecules?

A) dispersion forces
B) hydrogen bonding
C) polar-polar interaction
D) gravity

Question 9

Select the correct statement about the C-H hydrogen bonds in methane, CH₄.

A) The C-H bonds in methane may participate in hydrogen bonding with water.
B) The C-H bonds in methane are polar.
C) The C-H bonds in methane are nonpolar.
D) There is a very large difference in electronegativity between the carbon atom and hydrogen atom.

Question 10

When methane is forced into liquid water, a clathrate forms. The clathrate is a

A) hydrogen bond between water and methane.
B) cage of water molecules that surrounds the methane molecules.
C) cage of methane molecules that surrounds the water molecules.
D) pocket of methane gas within the water.

Question 11

Which of the following examples describes an increase in entropy?

A) stacking wooden blocks
B) making sand castles
C) organizing a closet
D) dropping a stack of organized papers

Question 12

When methane is added to water, the formation of a clathrate

A) decreases the entropy of the system.
B) increases the entropy of the system.
C) releases energy from the system.
D) does not change the entropy of the system.

Question 13

Forcing methane into water causes

A) a release of energy from the system.
B) no change in energy for the system.
C) an expenditure of energy on the system.
D) energy to be converted to matter.

Question 14

When two or more nonpolar molecules are added to water, the hydrophobic effect causes the nonpolar molecule to

A) disperse throughout the water.
B) bind strongly with the water.
C) aggregate together.
D) evaporate from the water.

Question 15

The hydrophobic interaction between nonpolar molecules in water does which of the following?

A) shields some of the nonpolar molecules' surface from the surrounding water
B) increases the entropy penalty for forcing the water into a more orderly state
C) exposes more of the nonpolar molecules' surface to the surrounding water
D) disperses the nonpolar molecules throughout the solvent water

Question 16

A substance that is water soluble is considered

A) lypophilic.
B) hydrophilic.
C) hydrophobic.
D) polar.

Question 17

What makes methanol, CH₃OH, easily dissolve in water?

A) C-H bond polarity
B) The carbon atom can interact with the water's hydrogen-bonding network.
C) The C-H group can incorporate into the water's hydrogen-bonding network.
D) The O-H group can incorporate into the water's hydrogen-bonding network.

Question 18

Which pair of molecules will most likely interact to form an attraction between them?

A) CH₄ and CH₃OH
B) H2O and CH₃OH
C) CH₄ and H₂O
D) none of the above (None of the pairs can interact to form an attraction.)

Question 19

Which of the following hydrocarbons would have the highest boiling point?

A) CH₄
B) CH₃CH₃
C) CH₃CH₂CH₃
D) CH₃CH₂CH₂CH₃

Question 20

What type of attractive force allows hydrocarbons to exist as a liquid?

A) dipole-dipole
B) hydrogen bonding
C) dispersion forces
D) gravity

Question 21

Dispersion forces in hydrocarbons increase with

A) increasing size of the hydrocarbon.
B) decreasing size of the hydrocarbon.
C) magnitude of permanent dipole of the hydrocarbon.
D) number of O-H groups.

Question 22

An instantaneous dipole in a hydrocarbon __________ dipole in a neighboring hydrocarbon.

A) induces a temporary
B) induces a permanent
C) inhibits a temporary
D) does not affect a

Question 23

Which of the following molecules would be expected to be most soluble in the hydrocarbon hexane?

A) CH₃OH
B) CH₃CH₂OH
C) CH₃CH₂CH₂OH
D) CH₃CH₂CH₂CH₂OH

Question 24

What forms adipose tissue?

A) muscle protein
B) a collection of cells that store hexane
C) a collection of cells that store glycerol
D) a collection of cells that store triglycerides

Question 25

Which of the following vitamins would be fat-soluble?

A)
B)
C)
D)

Question 26

Which of the following vitamins would be water-soluble?

A)
B)
C)
D)

Question 27

Select the false statement about water-soluble vitamins.

A) Even only one O-H group in a vitamin will ensure it is water soluble.
B) Water-soluble vitamins must contain sufficient polar groups, such as O-H, to offset hydrophobic properties.
C) Two water-soluble vitamins may differ in their solubility in water.
D) Even water-soluble vitamins will contain some hydrophobic parts.

Question 28

Which of the statements best describes the USDA Recommended Dietary Allowance (RDA) for vitamins?

A) The RDA for fat-soluble vitamins is typically higher than that for water-soluble vitamins.
B) The RDA for fat-soluble vitamins is typically lower than that for water-soluble vitamins.
C) The RDA for fat-soluble vitamins is typically similar to that for water-soluble vitamins.
D) There is no RDA for vitamins.

Question 29

Why may fat-soluble vitamins become toxic?

A) Because they are composed primarily of hydrophobic parts, they are naturally more toxic.
B) They accumulate in fat tissues and are not readily excreted from the body.
C) The transport molecules required to move them throughout the body are toxic.
D) They form solids in the blood stream and block blood flow.

Question 30

The formation of a micelle when detergent is placed into water is considered

A) crystallization.
B) condensation.
C) precipitation.
D) self-assembly.

Question 31

Which is the best description of how phospholipids self-assemble?

A) spherical micelle with fatty acids on the interior of the micelle
B) spherical micelle with polar group on the interior of the micelle
C) sandwich with fatty acids forming two layers that are exposed to water
D) sandwich with polar groups forming two layers that are exposed to water

Question 32

What material(s) compose a cell membrane?

A) cellulose
B) membrane protein only
C) membrane protein and phospholipids
D) phospholipids only

Question 33

How is water transported across a cell membrane?

A) The protein aquaporin provides a hydrophilic pathway through the cell membrane.
B) Water is soluble within the cell membrane and can easily move through it.
C) Water links with the protein aquaporin, then this pair moves through the cell membrane.
D) Water moves through pores where the phospholipids do not fit tightly together in the bilayer.

Question 34

Why does a solution of sodium chloride, NaCl, in water conduct electricity?

A) Pure water is a very good conductor of electricity.
B) Solid NaCl is a very good conductor of electricity, so the NaCl particles in the solution conduct electricity.
C) NaCl breaks into the ions Na+ and Cl- that may move through the solution to conduct electricity.
D) The NaCl particle forms a bond with water, thus allowing the solution to conduct electricity.

Question 35

Which of the following substances is an electrolyte in water?

A) KCl
B) CH₃OH
C) sucrose
D) CH₃CH₃

Question 36

A negatively charged electrode, the cathode, and a positively charge electrode, the cathode, are placed into an aqueous solution of sodium chloride. In which direction do the Na+ ions flow?

A) toward the anode
B) toward the cathode
C) The direction of travel is not affected by the electrodes.
D) toward both electrodes

Question 37

Why does NaCl dissolve in water?

A) The NaCl particle is small enough to fit between water molecules
B) The partial charges on the NaCl are attracted to the partial charges on the water.
C) Water dissociates into H+ and OH- ions that can dissolve NaCl.
D) NaCl dissociates into the ions Na+ and Cl- that are highly attracted to the partial charges on the H2O molecule.

Question 38

Which of the following pairs of solutions will form a precipitate when combined?

A) NaCl solution and NH₄NO₃ solution
B) NaCl solution and AgNO₃ solution
C) KCO₃ solution and NH₄NO₃ solution
D) AgNO₃ solution and KClO₃ solution

Question 39

Select the complete ionic equation for the mixing of sodium carbonate, Na2CO3, solution and calcium nitrate, Ca(NO3)2, solution.

A) Na₂CO₃(aq) + Ca(NO₃)2(aq)  CaCO₃(s) + 2NaNO₃(aq)
B) 2Na+(aq) + CO₃2-(aq) + Ca2+(aq) + 2NO₃-(aq)  CaCO₃(s) + 2Na+(aq) + 2NO₃-(aq)
C) CO₃2-(aq) + Ca2+(aq)  CaCO₃(s)
D) 2Na+(aq) + CO₃2-(aq) + Ca2+(aq) + 2NO₃-(aq)  CaCO₃(s)

Question 40

Select the net ionic equation for the mixing of silver nitrate, AgNO3, solution and potassium iodide, KI, solution.

A) Ag+(aq) + I-(aq)  AgI(s)
B) AgNO₃(aq) + KI(aq)  AgI(s) + KNO₃(aq)
C) Ag+(aq) + NO₃-(aq) + K+(aq) + I-(aq)  AgI(s) + NO₃-(aq) + K+(aq)
D) Ag+(aq) + NO₃-(aq) + K+(aq) + I-(aq)  AgI(s)

Question 41

Which of the following substances would not be good to be present within the interior of a cell?

A) NaCl
B) NH₄NO₃
C) CaCO₃
D) KI

Question 42

In a total ionic equation, where would spectator ions be found?

A) reactant side
B) product side
C) both reactant and product sides
D) neither reactant or product side

Question 43

How do Ions move across the cell membrane?

A) Ions are soluble in the polar ends of the phospholipids.
B) Ions form cation-anion pairs that are soluble in the nonpolar interior of the bilayer.
C) Proteins called ion channels allow the ions to cross the membrane.
D) The ions squeeze between the phospholipids.

Question 44

Nerve cells send electrical signals by pumping ions across the cell membrane. What prevents the ions from freely flowing across the membrane?

A) ion channels
B) nonpolar interior of the phospholipid bilayer
C) They bind to the polar ends of the phospholipid bilayer.
D) Water only exists on the interior of the cell.

Question 45

Certain hydrocarbons exist in the liquid state because of an intermolecular attraction called ____________________.

Question 46

A measure of the degree of randomness or disorder within a system of atoms or molecules is ____________________.

Question 47

A momentary fluctuation in the electron density of a nonpolar molecule produces an ____________________ dipole.

Question 48

A molecule capable of dissolving in a nonpolar solvent is ____________________-soluble.

Question 49

____________________-soluble vitamins may eventually become toxic in the body.

Question 50

Phospholipids self-assemble to form a ____________________.

Question 51

Ions are transported across cell membranes by ____________________.

Question 52

What causes an instantaneous dipole in a hydrocarbon?

Question 53

What factors are considered when determining whether an alcohol is soluble in water?

Question 54

Explain why a triglyceride behaves like a nonpolar solvent.

Question 55

Why does the USDA require a higher dose of water-soluble vitamins than fat-soluble vitamins?

Question 56

Describe the structure of a detergent micelle.

Question 57

Describe the difference between a triglyceride and phospholipid.

Question 58

Describe an ion channel.