Question 1

Why can't the elements of a compound be separated from one another by physical means?

Accepted Answer

A) They are too homogeneous when found within a compound. 
B) Their atoms are too tightly bound to one another. 
C) Elements found within a compound tend to be inert. 
D) Elements tend not to be soluble in water. 
A) They are too homogeneous when found within a compound. 
B) Their atoms are too tightly bound to one another. 
C) Elements found within a compound tend to be inert. 
D) Elements tend not to be soluble in water.

Question 2

How would you classify the following material? a cappuccino (with foam)

Accepted Answer

A) a suspension 
B) a heterogeneous mixture 
C) a solution 
D) an element 
E) a compound 
A) a suspension 
B) a heterogeneous mixture 
C) a solution 
D) an element 
E) a compound

Question 3

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 4

A student is told to use 20.0 grams of sodium chloride to make an aqueous solution that has a concentration of 10.0 grams of sodium chloride per liter of solution. Assuming that 20.0 grams of sodium chloride has a volume of 7.5 milliliters, about how much water will she use in making this solution?

Accepted Answer

A) 9.25 L 
B) 9.5 L 
C) 9.9925 L 
D) 10 L 
A) 9.25 L 
B) 9.5 L 
C) 9.9925 L 
D) 10 L

Question 5

If you were to increase the pressure of a gas above a liquid (such as by pressing a piston above a liquid)what happens?

Accepted Answer

A) The gas is forced into solution and the solubility increases. 
B) The solution is compressed and the gas is forced out of the solvent. 
C) The pressure goes down and the gas moves out of the solvent. 
D) The pressure goes down and the gas goes into the solvent. 
E) The amount of gas in the solution would stay the same. 
A) The gas is forced into solution and the solubility increases. 
B) The solution is compressed and the gas is forced out of the solvent. 
C) The pressure goes down and the gas moves out of the solvent. 
D) The pressure goes down and the gas goes into the solvent. 
E) The amount of gas in the solution would stay the same.

Question 6

Which of the following statements describes a saturated solution?

Accepted Answer

A) a solution where the solvent cannot dissolve any more solute 
B) a solution of salt water with salt at the bottom 
C) a carbonated beverage with bubbles 
D) all of the above 
E) none of the above 
A) a solution where the solvent cannot dissolve any more solute 
B) a solution of salt water with salt at the bottom 
C) a carbonated beverage with bubbles 
D) all of the above 
E) none of the above

Question 7

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 8

How many grams of sodium chloride are needed to make 15 L of a solution that has a concentration of 3.0 g per liter of solution?

Accepted Answer

A) 30 g 
B) 141 g 
C) 5 g 
D) 45 g 
A) 30 g 
B) 141 g 
C) 5 g 
D) 45 g

Question 9

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 10

How are intermolecular forces and solubility related?

Accepted Answer

A) Solubility depends on the solvent's ability to overcome the intermolecular forces in a solid. 
B) Solubility depends on the solute's ability to overcome the intermolecular forces in the solvent. 
C) Solubility is a measure of how strong a solvent's intermolecular forces are. 
D) Solubility is a measure of how weak the intermolecular forces in the solute are. 
E) none of the above 
A) Solubility depends on the solvent's ability to overcome the intermolecular forces in a solid. 
B) Solubility depends on the solute's ability to overcome the intermolecular forces in the solvent. 
C) Solubility is a measure of how strong a solvent's intermolecular forces are. 
D) Solubility is a measure of how weak the intermolecular forces in the solute are. 
E) none of the above

Question 11

If the solubility of a compound is 30 grams per liter, how much solid is left undissolved if you mix 30 g of the compound in 0.33 L of solution?

Accepted Answer

A) 20 g 
B) 10 g 
C) 0 g 
D) 30 g 
E) 33 g 
A) 20 g 
B) 10 g 
C) 0 g 
D) 30 g 
E) 33 g

Question 12

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 13

Mixtures can be separated into their components by taking advantage of differences in the chemical properties of the components. Why might this separation method be less convenient than taking advantage of differences in the physical properties of the components?

Accepted Answer

A) A chemical property involves a chemical change so that you no longer have what you had. 
B) Chemical properties are not as apparent as are physical properties. 
C) The chemical properties of the components of a mixture are too similar to each other. 
D) The chemical properties of the components of a mixture are too different from each other. 
A) A chemical property involves a chemical change so that you no longer have what you had. 
B) Chemical properties are not as apparent as are physical properties. 
C) The chemical properties of the components of a mixture are too similar to each other. 
D) The chemical properties of the components of a mixture are too different from each other.

Question 14

Why are there few odors emanating from a properly managed composting toilet?

Accepted Answer

A) Tight seals prevent the escape of odors. 
B) Odors are absorbed by a layer of water. 
C) Decomposition is aerobic. 
D) The ventilation system steers odors through a carbon filter. 
A) Tight seals prevent the escape of odors. 
B) Odors are absorbed by a layer of water. 
C) Decomposition is aerobic. 
D) The ventilation system steers odors through a carbon filter.

Question 15

Which of the following statements best describes what is happening in a water softening unit?

Accepted Answer

A) The hard ions in water are exchanged for ions that do not interact as strongly with soaps. 
B) The hard ions are all trapped in the softener, which filets out all the ions. 
C) The ions in the water softener are softened by chemically bonding with sodium. 
D) The sodium is removed from the water, making the water interact less with the soap molecules. 
E) none of the above 
A) The hard ions in water are exchanged for ions that do not interact as strongly with soaps. 
B) The hard ions are all trapped in the softener, which filets out all the ions. 
C) The ions in the water softener are softened by chemically bonding with sodium. 
D) The sodium is removed from the water, making the water interact less with the soap molecules. 
E) none of the above

Question 16

Deuterium oxide, D2O, and water, H2O, have the same chemical structure and differ only in that D2O possesses the deuterium isotope of hydrogen, whereas water possesses the protium isotope. Deuterium oxide, also known as "heavy water," is 11 percent heavier than water. Might you expect its boiling temperature also to be about 11 percent greater? Why or why not?

Accepted Answer

A) The mass of the molecules has a far greater influence on the boiling temperature of the substance than does the polarity of the molecules, so D2O boils at a higher temperature. 
B) Since they have the same chemical structures, there is a similar molecular attraction between the molecules, so their boiling temperatures are similar. 
C) Since deuterium is radioactive, it breaks down more easily, so it has a lower boiling temperature than water. 
D) Since boiling temperature is a measure of the speed of a molecule, the heavier molecules move slower and thus have a higher boiling temperature. 
A) The mass of the molecules has a far greater influence on the boiling temperature of the substance than does the polarity of the molecules, so D2O boils at a higher temperature. 
B) Since they have the same chemical structures, there is a similar molecular attraction between the molecules, so their boiling temperatures are similar. 
C) Since deuterium is radioactive, it breaks down more easily, so it has a lower boiling temperature than water. 
D) Since boiling temperature is a measure of the speed of a molecule, the heavier molecules move slower and thus have a higher boiling temperature.

Question 17

Which of the following boxes represents a suspension?       A B C

Accepted Answer

A) Only A represents a suspension. 
B) Only B represents a suspension. 
C) Only C represents a suspension. 
D) Each of these could represent a submicroscopic portion of a suspension. 
A) Only A represents a suspension. 
B) Only B represents a suspension. 
C) Only C represents a suspension. 
D) Each of these could represent a submicroscopic portion of a suspension.

Question 18

How many molecules of sucrose are in a 0.5 moles of sucrose?

Accepted Answer

A) 3.01 × 1023 molecules of sucrose 
B) 6.02 × 1023 molecules of sucrose 
C) 12.04 × 1023 molecules of sucrose 
D) 0.5 
E) 1 gram 
A) 3.01 × 1023 molecules of sucrose 
B) 6.02 × 1023 molecules of sucrose 
C) 12.04 × 1023 molecules of sucrose 
D) 0.5 
E) 1 gram

Question 19

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 20

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

Exam 16: Mixtures

Why can't the elements of a compound be separated from one another by physical means?

How would you classify the following material? a cappuccino (with foam)

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?

A student is told to use 20.0 grams of sodium chloride to make an aqueous solution that has a concentration of 10.0 grams of sodium chloride per liter of solution. Assuming that 20.0 grams of sodium chloride has a volume of 7.5 milliliters, about how much water will she use in making this solution?

If you were to increase the pressure of a gas above a liquid (such as by pressing a piston above a liquid)what happens?

Which of the following statements describes a saturated solution?

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

How many grams of sodium chloride are needed to make 15 L of a solution that has a concentration of 3.0 g per liter of solution?

Why does oxygen have such a low solubility in water?

How are intermolecular forces and solubility related?

If the solubility of a compound is 30 grams per liter, how much solid is left undissolved if you mix 30 g of the compound in 0.33 L of solution?

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

Mixtures can be separated into their components by taking advantage of differences in the chemical properties of the components. Why might this separation method be less convenient than taking advantage of differences in the physical properties of the components?

Why are there few odors emanating from a properly managed composting toilet?

Which of the following statements best describes what is happening in a water softening unit?

Which of the following boxes represents a suspension? A B C

How many molecules of sucrose are in a 0.5 moles of sucrose?

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

Which of the following solutions is the most concentrated?

Patterns of Motion and Equilibrium

Newtons Laws of Motion

Momentum and Energy

Gravity, Projectiles, and Satellites

Fluid Mechanics

Thermal Energy and Thermodynamics

Heat Transfer and Change of Phase

Static and Current Electricity

Magnetism and Electromagnetic Induction

Waves and Sound

Light

Atoms and the Periodic Table

The Atomic Nucleus and Radioactivity

Elements of Chemistry

How Atoms Bond and Molecules Attract

How Chemicals React

Two Classes of Chemical Reactions

Organic Compounds

Rocks and Minerals

Plate Tectonics and Earths Interior

Shaping Earths Surface

Geologic Timereading the Rock Record

The Oceans, Atmosphere, and Climatic Effects

Driving Forces of Weather

The Solar System

Stars and Galaxies

The Structure of Space and Time

Prologue: the Nature of Science

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