Question 1

Which of the above might best describe how soap behaves in a nonpolar solvent like turpentine?

Accepted Answer

A) a 
B) b 
C) c 
D) d 
E) none of the above 
A) a 
B) b 
C) c 
D) d 
E) none of the above

Question 2

Red blood cells have a high concentration of dissolved ions. When placed into pure water they rupture. Why?

Accepted Answer

A) Osmosis draws water into the cell until it pops. 
B) Water dissolves the cell membrane. 
C) Osmosis draws water out of the cell until it tears. 
D) The cells are not stable outside of a biological host. 
E) none of the above 
A) Osmosis draws water into the cell until it pops. 
B) Water dissolves the cell membrane. 
C) Osmosis draws water out of the cell until it tears. 
D) The cells are not stable outside of a biological host. 
E) none of the above

Question 3

What is the difference between a dipole-dipole interaction and an ion-dipole interaction?

Accepted Answer

A) one involves dipole attraction between neutral molecules while the other involves dipole interactions with ions 
B) one involves hydrogen bonding while the other does not 
C) one involves salts and water while the other doesn't involve water 
D) one involves ionic molecules interacting with other ionic molecules while the other deals with polar molecules 
E) none of the above 
A) one involves dipole attraction between neutral molecules while the other involves dipole interactions with ions 
B) one involves hydrogen bonding while the other does not 
C) one involves salts and water while the other doesn't involve water 
D) one involves ionic molecules interacting with other ionic molecules while the other deals with polar molecules 
E) none of the above

Question 4

Which of the following might have the best solubility in water?

Accepted Answer

A) CH3OH 
B) Cl2 
C) O2 
D) CH3CH3 
E) none of the above 
A) CH3OH 
B) Cl2 
C) O2 
D) CH3CH3 
E) none of the above

Question 5

Two chemical structures are shown, one of a typical gasoline molecule and the other of a typical motor oil molecule. Which is which?   Base your reasoning not on memorization but rather upon what you know about molecular interactions and the various physical properties of gasoline and motor oil.

Accepted Answer

A) Structure A represents the gas molecule because there are more bonds to gain energy from, giving it a higher energy content than oil. 
B) Structure A represents motor oil, illustrating a molecule with greater induced dipole-induced dipole molecular interactions thus, the molecules are strongly attracted to one another. 
C) Structure B represents the oil molecule. Because oil molecules are smaller, they can compact closer together, giving the appearance of a thicker solution than gasoline. 
D) Structure B represents crude oil which is processed to generate longer molecules of gasoline to prevent toxic vapors from harming consumers. 
A) Structure A represents the gas molecule because there are more bonds to gain energy from, giving it a higher energy content than oil. 
B) Structure A represents motor oil, illustrating a molecule with greater induced dipole-induced dipole molecular interactions thus, the molecules are strongly attracted to one another. 
C) Structure B represents the oil molecule. Because oil molecules are smaller, they can compact closer together, giving the appearance of a thicker solution than gasoline. 
D) Structure B represents crude oil which is processed to generate longer molecules of gasoline to prevent toxic vapors from harming consumers.

Question 6

Why does oxygen have such a low solubility in water?

Accepted Answer

A) Water's attraction for itself is stronger than its attraction for oxygen molecules. 
B) Water and oxygen only attract one another by means of weak dipole-induced dipole attractions. 
C) The hydrogen bonding in water keeps the oxygen solubility low. 
D) Both A and B are true. 
A) Water's attraction for itself is stronger than its attraction for oxygen molecules. 
B) Water and oxygen only attract one another by means of weak dipole-induced dipole attractions. 
C) The hydrogen bonding in water keeps the oxygen solubility low. 
D) Both A and B are true.

Question 7

If you need 10. moles of sucrose, how many liters of a 4.0 molar solution would you need?

Accepted Answer

A) 2.5 L 
B) 0.25 L 
C) 25 L 
D) 10. L 
E) none of the above 
A) 2.5 L 
B) 0.25 L 
C) 25 L 
D) 10. L 
E) none of the above

Question 8

A sealed plastic bottle is filled with enough sand so that the bottle floats just beneath the surface in ocean water. Some sand is then removed and the bottle is then placed in some fresh water where it floats just beneath the surface. What is true about the amount of sand that was removed from the bottle?

Accepted Answer

A) The mass of sand removed divided by the volume of the original plastic bottle equals the density of the ocean water. 
B) The mass of the sand removed divided by the mass of the sand remaining in the plastic bottle is the same ratio as the density of fresh water to the density of ocean water. 
C) The amount of sand removed from the plastic bottle equals the amount of salt dissolved in the ocean water. 
D) The mass of the sand removed multiplied by the density of ocean water equals the volume of the plastic bottle. 
A) The mass of sand removed divided by the volume of the original plastic bottle equals the density of the ocean water. 
B) The mass of the sand removed divided by the mass of the sand remaining in the plastic bottle is the same ratio as the density of fresh water to the density of ocean water. 
C) The amount of sand removed from the plastic bottle equals the amount of salt dissolved in the ocean water. 
D) The mass of the sand removed multiplied by the density of ocean water equals the volume of the plastic bottle.

Question 9

Which of the following is the weakest form of interatomic attraction?

Accepted Answer

A) a chemical bond 
B) an ion-dipole interaction 
C) a dipole-dipole interaction 
D) a dipole-induced dipole interaction 
E) an induced dipole-induced dipole interaction 
A) a chemical bond 
B) an ion-dipole interaction 
C) a dipole-dipole interaction 
D) a dipole-induced dipole interaction 
E) an induced dipole-induced dipole interaction

Question 10

In a solution made from one teaspoon of sugar and one liter of water, which is the solute?

Accepted Answer

A) sugar 
B) water 
C) the teaspoon 
D) both sugar and water 
E) none of the above 
A) sugar 
B) water 
C) the teaspoon 
D) both sugar and water 
E) none of the above

Question 11

Consider the boiling points of the following compounds and their solubilities in room-temperature water. Why does the solubilities in water go down as the boiling points of these alcohols go up.

Accepted Answer

A) Larger molecules are less attracted to one another by induced dipole-induced dipole as well as by dipole-dipole and dipole-induced dipole attractions. 
B) As the boiling increases, it is more difficult to keep the alcohol from evaporating out of solution. 
C) As the boiling point increases, the size of the alcohol molecules decreases. 
D) Larger molecules are more attracted to one another by induced dipole-induced dipole as well as by dipole-dipole and dipole-induced dipole attractions. 
A) Larger molecules are less attracted to one another by induced dipole-induced dipole as well as by dipole-dipole and dipole-induced dipole attractions. 
B) As the boiling increases, it is more difficult to keep the alcohol from evaporating out of solution. 
C) As the boiling point increases, the size of the alcohol molecules decreases. 
D) Larger molecules are more attracted to one another by induced dipole-induced dipole as well as by dipole-dipole and dipole-induced dipole attractions.

Question 12

Why is calcium fluoride, Ca   , a high melting point crystalline solid while tin (IV)chloride,   , is a volatile liquid?

Accepted Answer

A) There is no theory to predict the physical property of melting point. Melting point temperatures are empirically determined. 
B) Actually, we would predict these results to be the opposite. Since each metal is combined with a group 17 halogen, the heavier metal (tin)combination should have the higher melting point. 
C) Ca   is a small, linear, non-polar molecule, while   is a huge tetrahedral structure. Therefore the bonds in calcium fluoride tend to give it a higher melting point temperature. 
D) Ionic compounds formed by elements on opposite sides of the periodic table, like   , tend to have higher melting points than more covalently bonded structures, like   . 
A) There is no theory to predict the physical property of melting point. Melting point temperatures are empirically determined. 
B) Actually, we would predict these results to be the opposite. Since each metal is combined with a group 17 halogen, the heavier metal (tin)combination should have the higher melting point. 
C) Ca   is a small, linear, non-polar molecule, while   is a huge tetrahedral structure. Therefore the bonds in calcium fluoride tend to give it a higher melting point temperature. 
D) Ionic compounds formed by elements on opposite sides of the periodic table, like   , tend to have higher melting points than more covalently bonded structures, like   .

Question 13

Fish don't live very long in water that has just been boiled and brought back to room temperature. Suggest why.

Accepted Answer

A) There is now a higher concentration of dissolved C   in the water. 
B) The nutrients in the water have been destroyed. 
C) Since some of the water was evaporated while boiling, the salts in the water are now more concentrated. This has a negative effect on the fish. 
D) The boiling process removes the air that was dissolved in the water. Upon cooling the water is void of its usual air content, hence, the fish drown. 
A) There is now a higher concentration of dissolved C   in the water. 
B) The nutrients in the water have been destroyed. 
C) Since some of the water was evaporated while boiling, the salts in the water are now more concentrated. This has a negative effect on the fish. 
D) The boiling process removes the air that was dissolved in the water. Upon cooling the water is void of its usual air content, hence, the fish drown.

Question 14

How can you tell whether a sugar solution is saturated or not?

Accepted Answer

A) Add more sugar, if it dissolves, it is saturated. 
B) There will be a precipitate if the water is heated. 
C) As long as there are more water molecules than sugar molecules, there is a saturated solution. 
D) Add more sugar. If it does not dissolve after mixing, the solution is saturated. 
A) Add more sugar, if it dissolves, it is saturated. 
B) There will be a precipitate if the water is heated. 
C) As long as there are more water molecules than sugar molecules, there is a saturated solution. 
D) Add more sugar. If it does not dissolve after mixing, the solution is saturated.

Question 15

If an ionic bond is stronger than a dipole-dipole interaction, how can water dissolve an ionic compound?

Accepted Answer

A) The ion-dipole interactions of a bunch of water molecules gang up on the strong ionic bond and pull it into the solution. 
B) The ionic bond is weakened by the ion-dipole interactions and ionic repulsion ejects the ions from the crystal. 
C) The ion-dipole interaction causes the ions to heat up and vibrate free of the crystal. 
D) The ions never overcome their interatomic attraction and therefore are not soluble. 
E) none of the above 
A) The ion-dipole interactions of a bunch of water molecules gang up on the strong ionic bond and pull it into the solution. 
B) The ionic bond is weakened by the ion-dipole interactions and ionic repulsion ejects the ions from the crystal. 
C) The ion-dipole interaction causes the ions to heat up and vibrate free of the crystal. 
D) The ions never overcome their interatomic attraction and therefore are not soluble. 
E) none of the above

Question 16

What happens when the molecule-to-molecule attractions in the solute are comparable to those in the solvent?

Accepted Answer

A) The solute can have infinite solubility in the solvent. 
B) The solute does not dissolve in the solvent. 
C) The material has only limited solubility in the solvent. 
D) The solution will become saturated. 
E) none of the above 
A) The solute can have infinite solubility in the solvent. 
B) The solute does not dissolve in the solvent. 
C) The material has only limited solubility in the solvent. 
D) The solution will become saturated. 
E) none of the above

Question 17

Why do red blood cells, which contain an aqueous solution of dissolved ions and minerals, burst when placed in fresh water?

Accepted Answer

A) The dissolved ions provide a pressure that eventually bursts open the cell. 
B) More water molecules enter the cell than leave the cell. 
C) The fresh water acts to dissolve the blood cell wall. 
D) all of the above 
A) The dissolved ions provide a pressure that eventually bursts open the cell. 
B) More water molecules enter the cell than leave the cell. 
C) The fresh water acts to dissolve the blood cell wall. 
D) all of the above

Question 18

What is the molarity when water is added to 2 moles of sodium chloride to make 0.5 liter of solution?

Accepted Answer

A) 8 M 
B) 4 M 
C) 5 M 
D) 2.5 M 
A) 8 M 
B) 4 M 
C) 5 M 
D) 2.5 M

Question 19

Why is a large quantity of water used in industrial processes in the U.S. purified by desalinization?

Accepted Answer

A) The sources are brackish or metal ion rich. 
B) The sources are ocean water. 
C) There is not enough fresh water. 
D) It is less expensive than using fresh water. 
E) none of the above 
A) The sources are brackish or metal ion rich. 
B) The sources are ocean water. 
C) There is not enough fresh water. 
D) It is less expensive than using fresh water. 
E) none of the above

Question 20

Why isn't distillation used commercially to purify water?

Accepted Answer

A) Water requires large amounts of energy to boil affordably. 
B) Bacteria are not killed during the distillation process. 
C) Odd smelling contaminants boil at lower temperatures than water and so are impossible to remove. 
D) Distillation does not remove suspended particles such as dirt and humus. 
E) none of the above 
A) Water requires large amounts of energy to boil affordably. 
B) Bacteria are not killed during the distillation process. 
C) Odd smelling contaminants boil at lower temperatures than water and so are impossible to remove. 
D) Distillation does not remove suspended particles such as dirt and humus. 
E) none of the above

Which of the above might best describe how soap behaves in a nonpolar solvent like turpentine?

Red blood cells have a high concentration of dissolved ions. When placed into pure water they rupture. Why?

What is the difference between a dipole-dipole interaction and an ion-dipole interaction?

Which of the following might have the best solubility in water?

Two chemical structures are shown, one of a typical gasoline molecule and the other of a typical motor oil molecule. Which is which? Base your reasoning not on memorization but rather upon what you know about molecular interactions and the various physical properties of gasoline and motor oil.

Why does oxygen have such a low solubility in water?

If you need 10. moles of sucrose, how many liters of a 4.0 molar solution would you need?

Which of the following is the weakest form of interatomic attraction?

In a solution made from one teaspoon of sugar and one liter of water, which is the solute?

Consider the boiling points of the following compounds and their solubilities in room-temperature water. Why does the solubilities in water go down as the boiling points of these alcohols go up.

Why is calcium fluoride, Ca , a high melting point crystalline solid while tin (IV)chloride, , is a volatile liquid?

Fish don't live very long in water that has just been boiled and brought back to room temperature. Suggest why.

How can you tell whether a sugar solution is saturated or not?

If an ionic bond is stronger than a dipole-dipole interaction, how can water dissolve an ionic compound?

What happens when the molecule-to-molecule attractions in the solute are comparable to those in the solvent?

Why do red blood cells, which contain an aqueous solution of dissolved ions and minerals, burst when placed in fresh water?

What is the molarity when water is added to 2 moles of sodium chloride to make 0.5 liter of solution?

Why is a large quantity of water used in industrial processes in the U.S. purified by desalinization?

Why isn't distillation used commercially to purify water?

About Science

Particles of Matter

Elements of Chemistry

Subatomic Particles

The Atomic Nucleus

How Atoms Bond

How Water Behaves

How Chemicals React

Acids and Bases in Our Environment

Oxidations and Reductions Charge the World

Organic Compounds

Nutrients of Life

Medicinal Chemistry

Optimizing Food Production

Protection Water and Air Resources

Capturing Energy

Filters

Exam 7: How Molecules Mix

Which of the above might best describe how soap behaves in a nonpolar solvent like turpentine?

Red blood cells have a high concentration of dissolved ions. When placed into pure water they rupture. Why?

What is the difference between a dipole-dipole interaction and an ion-dipole interaction?

Which of the following might have the best solubility in water?

Two chemical structures are shown, one of a typical gasoline molecule and the other of a typical motor oil molecule. Which is which? Base your reasoning not on memorization but rather upon what you know about molecular interactions and the various physical properties of gasoline and motor oil.

Why does oxygen have such a low solubility in water?

If you need 10. moles of sucrose, how many liters of a 4.0 molar solution would you need?

Which of the following is the weakest form of interatomic attraction?

In a solution made from one teaspoon of sugar and one liter of water, which is the solute?

Consider the boiling points of the following compounds and their solubilities in room-temperature water. Why does the solubilities in water go down as the boiling points of these alcohols go up.

Why is calcium fluoride, Ca , a high melting point crystalline solid while tin (IV)chloride, , is a volatile liquid?

Fish don't live very long in water that has just been boiled and brought back to room temperature. Suggest why.

How can you tell whether a sugar solution is saturated or not?

If an ionic bond is stronger than a dipole-dipole interaction, how can water dissolve an ionic compound?

What happens when the molecule-to-molecule attractions in the solute are comparable to those in the solvent?

Why do red blood cells, which contain an aqueous solution of dissolved ions and minerals, burst when placed in fresh water?

What is the molarity when water is added to 2 moles of sodium chloride to make 0.5 liter of solution?

Why is a large quantity of water used in industrial processes in the U.S. purified by desalinization?

Why isn't distillation used commercially to purify water?

About Science

Particles of Matter

Elements of Chemistry

Subatomic Particles

The Atomic Nucleus

How Atoms Bond

How Water Behaves

How Chemicals React

Acids and Bases in Our Environment

Oxidations and Reductions Charge the World

Organic Compounds

Nutrients of Life

Medicinal Chemistry

Optimizing Food Production

Protection Water and Air Resources

Capturing Energy

Filters