Question 1

What is the purpose of allowing water to cascade or bubble in a fountain during the purification process?

Accepted Answer

A) to mix air into the water and improve flavor 
B) to remove radioactive gases 
C) to remove unpleasant smelling chemicals like sulfur 
D) all of the above 
E) only A and B 
A) to mix air into the water and improve flavor 
B) to remove radioactive gases 
C) to remove unpleasant smelling chemicals like sulfur 
D) all of the above 
E) only A and B

Question 2

Might reverse osmosis be used to obtain fresh water from a sugar-water solution?

Accepted Answer

A) No, osmosis and reverse osmosis only apply to aqueous solutions containing ions. 
B) Yes, reverse osmosis can be applied to any aqueous solution for the generation of fresh water. 
C) No, the molecular attractions between sugar and water are too strong. 
D) Yes, because sugar molecules are smaller than sodium or chloride ions. 
A) No, osmosis and reverse osmosis only apply to aqueous solutions containing ions. 
B) Yes, reverse osmosis can be applied to any aqueous solution for the generation of fresh water. 
C) No, the molecular attractions between sugar and water are too strong. 
D) Yes, because sugar molecules are smaller than sodium or chloride ions.

Question 3

What is molarity?

Accepted Answer

A) the number of moles of solute per liter of solution 
B) the number of grams of solute per liter of solution 
C) the number of moles of solute per liter of solvent 
D) the number of liters of solute per mole of solution 
E) none of the above 
A) the number of moles of solute per liter of solution 
B) the number of grams of solute per liter of solution 
C) the number of moles of solute per liter of solvent 
D) the number of liters of solute per mole of solution 
E) none of the above

Question 4

During osmosis ________.

Accepted Answer

A) the water moves into the concentrated solution faster than it leaves 
B) the ions move into the concentrated solution faster than they leave 
C) the water moves more slowly into the concentrated solution than it leaves 
D) the ions move into the concentrated solution slower than they leave 
E) all of the above 
A) the water moves into the concentrated solution faster than it leaves 
B) the ions move into the concentrated solution faster than they leave 
C) the water moves more slowly into the concentrated solution than it leaves 
D) the ions move into the concentrated solution slower than they leave 
E) all of the above

Question 5

A thin stream of water is pulled to a statically charged balloon. Might a small ice cube also be pulled to a statically charged balloon?

Accepted Answer

A) No, this behavior is unique to water while in it liquid state only. 
B) Yes, the same forces that cause the attraction in the liquid state are present in the solid state of water as well. 
C) Yes and No. While the ice remains completely solid, no attraction occurs. Once the ice begins to melt so that both phases are present, the attraction becomes apparent. 
D) Yes and No. Like the thin stream of water, the ice must be in motion in order for the attraction to be observed. 
A) No, this behavior is unique to water while in it liquid state only. 
B) Yes, the same forces that cause the attraction in the liquid state are present in the solid state of water as well. 
C) Yes and No. While the ice remains completely solid, no attraction occurs. Once the ice begins to melt so that both phases are present, the attraction becomes apparent. 
D) Yes and No. Like the thin stream of water, the ice must be in motion in order for the attraction to be observed.

Question 6

Why do water heaters lose their efficiency quicker in households with hard water?

Accepted Answer

A) The hard water calcium and magnesium ions corrode the heating element. 
B) The hard water calcium carbonate deposits oxidize the inner tank wall. 
C) The calcium carbonate on the inner surface of the hot water tank builds up to the point that it insulates the water from the heating element. 
D) The hard water calcium ions exchange with iron ions from the inner metal wall which react with the water heater base to form rust and deteriorate the bottom of the tank. 
A) The hard water calcium and magnesium ions corrode the heating element. 
B) The hard water calcium carbonate deposits oxidize the inner tank wall. 
C) The calcium carbonate on the inner surface of the hot water tank builds up to the point that it insulates the water from the heating element. 
D) The hard water calcium ions exchange with iron ions from the inner metal wall which react with the water heater base to form rust and deteriorate the bottom of the tank.

Question 7

The charges with sodium chloride are all balanced-for every positive sodium ion there is a corresponding negative chloride ion. Since its charges are balanced, how can sodium chloride be attracted to water, and vice versa?

Accepted Answer

A) Dispersion forces come into play as the sodium chloride and water come into close proximity. 
B) Hydrogen bonding in water allows the sodium chloride molecule to be attracted to the water molecule. 
C) As a water molecule gets close to the sodium chloride it can distinguish the various ions and it is thus attracted to an individual ion by ion-dipole forces. 
D) This is not a matter of attraction. Sodium chloride dissolves in water because water provides a medium in which the individual sodium and chloride ions can disperse. 
A) Dispersion forces come into play as the sodium chloride and water come into close proximity. 
B) Hydrogen bonding in water allows the sodium chloride molecule to be attracted to the water molecule. 
C) As a water molecule gets close to the sodium chloride it can distinguish the various ions and it is thus attracted to an individual ion by ion-dipole forces. 
D) This is not a matter of attraction. Sodium chloride dissolves in water because water provides a medium in which the individual sodium and chloride ions can disperse.

Question 8

Which of the following solutions is the most concentrated?

Accepted Answer

A) 0.5 L of a 3 molar solution 
B) 3.0 L of a 0.5 molar solution 
C) 2.0 L of a 1 molar solution 
D) 0.5 L of a 1 molar solution 
E) 2.0 L of a 2 molar solution 
A) 0.5 L of a 3 molar solution 
B) 3.0 L of a 0.5 molar solution 
C) 2.0 L of a 1 molar solution 
D) 0.5 L of a 1 molar solution 
E) 2.0 L of a 2 molar solution

Question 9

Which of the following would have the lowest melting point?

Accepted Answer

A) CCl4 
B) CBr4 
C) CF4 
D) CI4 
E) not enough information given 
A) CCl4 
B) CBr4 
C) CF4 
D) CI4 
E) not enough information given

Question 10

Which of the following describes reverse osmosis?

Accepted Answer

A) High pressure saltwater is forced against a semipermeable membrane and fresh water comes out. 
B) Saltwater is chemically reacted with aluminum particles, which chemically binds to the chloride ions. 
C) The water is heated until it evaporates and condenses in a pure form. 
D) High pressure saltwater is reacted with aluminum, which absorbs the sodium ions in an oxidation reaction. 
E) none of the above 
A) High pressure saltwater is forced against a semipermeable membrane and fresh water comes out. 
B) Saltwater is chemically reacted with aluminum particles, which chemically binds to the chloride ions. 
C) The water is heated until it evaporates and condenses in a pure form. 
D) High pressure saltwater is reacted with aluminum, which absorbs the sodium ions in an oxidation reaction. 
E) none of the above

Question 11

Which of the following describes an aqueous solution?

Accepted Answer

A) a mixture of some compound dissolved in water 
B) a mixture of polar molecules dissolved in a nonpolar solvent 
C) a mixture of water dispersed in an ionic compound 
D) a mixture of nonpolar molecules dissolved in a polar solvent 
E) none of the above 
A) a mixture of some compound dissolved in water 
B) a mixture of polar molecules dissolved in a nonpolar solvent 
C) a mixture of water dispersed in an ionic compound 
D) a mixture of nonpolar molecules dissolved in a polar solvent 
E) none of the above

Question 12

A sample of steel is composed of 5 percent carbon and 95 percent iron. Which is the solvent?

Accepted Answer

A) iron 
B) carbon 
C) steel 
D) Steel is not a solution, it is a mixture. 
E) A solid cannot be a solvent. 
A) iron 
B) carbon 
C) steel 
D) Steel is not a solution, it is a mixture. 
E) A solid cannot be a solvent.

Question 13

Why is it significantly less costly to purify fresh water through reverse osmosis than to purify salt water through reverse osmosis?

Accepted Answer

A) The osmotic pressure exerted by fresh water is less. 
B) The osmotic pressure exerted by fresh water is greater. 
C) For non-coastal regions, the salt water needs to be transported many miles from the oceans. 
D) The expense of reverse osmosis is not dependent upon the salt concentration in the water. 
A) The osmotic pressure exerted by fresh water is less. 
B) The osmotic pressure exerted by fresh water is greater. 
C) For non-coastal regions, the salt water needs to be transported many miles from the oceans. 
D) The expense of reverse osmosis is not dependent upon the salt concentration in the water.

Question 14

Which of the following material phases cannot form a solution?

Accepted Answer

A) solids 
B) liquids 
C) gases 
D) All of the above can form solutions. 
E) None of the above can form solutions. 
A) solids 
B) liquids 
C) gases 
D) All of the above can form solutions. 
E) None of the above can form solutions.

Question 15

Some people fear drinking distilled water because they have heard it leaches minerals from the body. What scientifically sound information might be offered to such a person?

Accepted Answer

A) add small amounts of salt to the distilled water before drinking it 
B) chill the distilled water to decrease its leaching potential 
C) buy distilled water that has also undergone reverse osmosis 
D) Distilled water is relatively pure water, which loses its purity once it mixes with everything else in your stomach. 
A) add small amounts of salt to the distilled water before drinking it 
B) chill the distilled water to decrease its leaching potential 
C) buy distilled water that has also undergone reverse osmosis 
D) Distilled water is relatively pure water, which loses its purity once it mixes with everything else in your stomach.

Question 16

When municipal water treatment plants are not available, which of the following methods of purification might be utilized?

Accepted Answer

A) chemical purification with chlorine 
B) reverse osmosis 
C) chemical purification with iodine 
D) boiling 
E) c and d 
A) chemical purification with chlorine 
B) reverse osmosis 
C) chemical purification with iodine 
D) boiling 
E) c and d

Question 17

Which of the following might best describe the product obtained from soap and hard water (i.e., soap scum)?

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 18

Cells at the top of a tree have a higher concentration of sugars than cells at the bottom. How might this fact assist a tree in moving water upward from its roots?

Accepted Answer

A) Cells with high concentrations of sugar are more dense. As these cells migrate downwards, cells containing fresh water are able to migrate upwards. 
B) Water is pushed upwards by osmostic pressure. 
C) It doesn't. In fact, water makes it to the top of a tree because that is where the water molecules are being evaporated. 
D) Fresh water is drawn upwards to the sugar containing cells by way of dipole-dipole molecular interactions. 
A) Cells with high concentrations of sugar are more dense. As these cells migrate downwards, cells containing fresh water are able to migrate upwards. 
B) Water is pushed upwards by osmostic pressure. 
C) It doesn't. In fact, water makes it to the top of a tree because that is where the water molecules are being evaporated. 
D) Fresh water is drawn upwards to the sugar containing cells by way of dipole-dipole molecular interactions.

Question 19

What is the purpose of treating water with chlorine gas or ozone during water purification?

Accepted Answer

A) to kill bacteria 
B) to improve taste 
C) to improve color 
D) to remove solids 
E) none of the above 
A) to kill bacteria 
B) to improve taste 
C) to improve color 
D) to remove solids 
E) none of the above

Question 20

The separation of charges within a polar molecule is called a(n)________.

Accepted Answer

A) dipole 
B) dipole-dipole 
C) ionic bond 
D) strong attraction 
E) polar bond 
A) dipole 
B) dipole-dipole 
C) ionic bond 
D) strong attraction 
E) polar bond

What is the purpose of allowing water to cascade or bubble in a fountain during the purification process?

Might reverse osmosis be used to obtain fresh water from a sugar-water solution?

What is molarity?

During osmosis ________.

A thin stream of water is pulled to a statically charged balloon. Might a small ice cube also be pulled to a statically charged balloon?

Why do water heaters lose their efficiency quicker in households with hard water?

The charges with sodium chloride are all balanced-for every positive sodium ion there is a corresponding negative chloride ion. Since its charges are balanced, how can sodium chloride be attracted to water, and vice versa?

Which of the following solutions is the most concentrated?

Which of the following would have the lowest melting point?

Which of the following describes reverse osmosis?

Which of the following describes an aqueous solution?

A sample of steel is composed of 5 percent carbon and 95 percent iron. Which is the solvent?

Why is it significantly less costly to purify fresh water through reverse osmosis than to purify salt water through reverse osmosis?

Which of the following material phases cannot form a solution?

Some people fear drinking distilled water because they have heard it leaches minerals from the body. What scientifically sound information might be offered to such a person?

When municipal water treatment plants are not available, which of the following methods of purification might be utilized?

Which of the following might best describe the product obtained from soap and hard water (i.e., soap scum)?

Cells at the top of a tree have a higher concentration of sugars than cells at the bottom. How might this fact assist a tree in moving water upward from its roots?

What is the purpose of treating water with chlorine gas or ozone during water purification?

The separation of charges within a polar molecule is called a(n)________.

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

What is the purpose of allowing water to cascade or bubble in a fountain during the purification process?

Might reverse osmosis be used to obtain fresh water from a sugar-water solution?

What is molarity?

During osmosis ________.

A thin stream of water is pulled to a statically charged balloon. Might a small ice cube also be pulled to a statically charged balloon?

Why do water heaters lose their efficiency quicker in households with hard water?

The charges with sodium chloride are all balanced-for every positive sodium ion there is a corresponding negative chloride ion. Since its charges are balanced, how can sodium chloride be attracted to water, and vice versa?

Which of the following solutions is the most concentrated?

Which of the following would have the lowest melting point?

Which of the following describes reverse osmosis?

Which of the following describes an aqueous solution?

A sample of steel is composed of 5 percent carbon and 95 percent iron. Which is the solvent?

Why is it significantly less costly to purify fresh water through reverse osmosis than to purify salt water through reverse osmosis?

Which of the following material phases cannot form a solution?

Some people fear drinking distilled water because they have heard it leaches minerals from the body. What scientifically sound information might be offered to such a person?

When municipal water treatment plants are not available, which of the following methods of purification might be utilized?

Which of the following might best describe the product obtained from soap and hard water (i.e., soap scum)?

Cells at the top of a tree have a higher concentration of sugars than cells at the bottom. How might this fact assist a tree in moving water upward from its roots?

What is the purpose of treating water with chlorine gas or ozone during water purification?

The separation of charges within a polar molecule is called a(n)________.

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