Question 1

How many grams of sugar (sucrose)are there in 5 liters of sugar water that has a concentration of 0.5 grams per liter of solution?

Accepted Answer

A) 50 g 
B) 25 g 
C) 2.5 g 
D) 1.5 g 
A) 50 g 
B) 25 g 
C) 2.5 g 
D) 1.5 g

Question 2

Does the concentration of chlorine in drinking water tend to increase or decrease as it leaves the water treatment plant and disperses into the community? Why?

Accepted Answer

A) Increases. As the chlorine reacts with the bacteria in the water, more chlorine is produced. 
B) Increases. As the water evaporates the chlorine concentration would increase in the remaining water. 
C) Decreases. Evaporative processes and reaction with organic bacteria would decrease the chlorine concentration. 
D) Neither. The chlorine concentration in the water does not vary as the water is dispersed into the community. 
A) Increases. As the chlorine reacts with the bacteria in the water, more chlorine is produced. 
B) Increases. As the water evaporates the chlorine concentration would increase in the remaining water. 
C) Decreases. Evaporative processes and reaction with organic bacteria would decrease the chlorine concentration. 
D) Neither. The chlorine concentration in the water does not vary as the water is dispersed into the community.

Question 3

Is the air in your house a homogeneous or heterogeneous mixture?

Accepted Answer

A) homogeneous because it is mixed very well 
B) heterogeneous because of the dust particles it contains 
C) homogeneous because it is all at the same temperature 
D) heterogeneous because it consists of different types of molecules 
A) homogeneous because it is mixed very well 
B) heterogeneous because of the dust particles it contains 
C) homogeneous because it is all at the same temperature 
D) heterogeneous because it consists of different types of molecules

Question 4

Why are noble gases infinitely soluble in noble gases?

Accepted Answer

A) The noble gases are attracted to each other by induced dipole-induced dipole attractions, but there is only one attraction per molecule. 
B) These are the smallest atoms on the periodic table. 
C) The molecules do not interact with each other, excluding other molecules. 
D) Noble gases can be mixed homogeneously in any proportion. 
A) The noble gases are attracted to each other by induced dipole-induced dipole attractions, but there is only one attraction per molecule. 
B) These are the smallest atoms on the periodic table. 
C) The molecules do not interact with each other, excluding other molecules. 
D) Noble gases can be mixed homogeneously in any proportion.

Question 5

Which of the following would be considered a homogeneous mixture?

Accepted Answer

A) wine 
B) hydrogen cyanide 
C) rusty iron 
D) pretzel 
E) sugar 
A) wine 
B) hydrogen cyanide 
C) rusty iron 
D) pretzel 
E) sugar

Question 6

Suggest why sodium chloride, NaCl, is insoluble in gasoline. Consider the electrical attractions.

Accepted Answer

A) Since this molecule is so small, there is not much opportunity for the gasoline to interact with it through any electrical attractions. 
B) Since gasoline is a very polar molecule, the salt can only form dipole-induced dipole bonds, which are very weak, giving it a low solubility in gasoline. 
C) Since gasoline is so strongly attracted to itself, the salt, NaCl is excluded. 
D) Salt is composed of ions that are too attracted to themselves. Gasoline is non-polar so salt and gasoline will not interact very well. 
A) Since this molecule is so small, there is not much opportunity for the gasoline to interact with it through any electrical attractions. 
B) Since gasoline is a very polar molecule, the salt can only form dipole-induced dipole bonds, which are very weak, giving it a low solubility in gasoline. 
C) Since gasoline is so strongly attracted to itself, the salt, NaCl is excluded. 
D) Salt is composed of ions that are too attracted to themselves. Gasoline is non-polar so salt and gasoline will not interact very well.

Question 7

What happens if you were to place a dilute solution that is in a bag made of a semipermeable membrane and were to then suspend it in a very concentrated solution?

Accepted Answer

A) The size of the suspended bag would decrease. 
B) The size of the suspended bag would increase. 
C) The size of the bag would not change. 
D) The solutions would eventually reach the same concentration. 
E) only c and d 
A) The size of the suspended bag would decrease. 
B) The size of the suspended bag would increase. 
C) The size of the bag would not change. 
D) The solutions would eventually reach the same concentration. 
E) only c and d

Question 8

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 9

What is the easiest way to eliminate organic components?

Accepted Answer

A) Aerate the solution and let bacteria consume the organics. 
B) Treat the solution with UV radiation. 
C) Filter the solution through activated carbon filters. 
D) reverse osmosis 
E) all of the above 
A) Aerate the solution and let bacteria consume the organics. 
B) Treat the solution with UV radiation. 
C) Filter the solution through activated carbon filters. 
D) reverse osmosis 
E) all of the above

Question 10

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 11

Water being purified using aluminum salts and a base is an example of ________.

Accepted Answer

A) a physical separation 
B) a chemical reaction 
C) an acid-base reaction 
D) a chemical separation 
E) none of the above 
A) a physical separation 
B) a chemical reaction 
C) an acid-base reaction 
D) a chemical separation 
E) none of the above

Question 12

The air that a scuba diver breathes is pressurized to counteract the pressure exerted by the surrounding water. Under these conditions, excessive amounts of nitrogen dissolves in bodily fluids, such as blood. If the diver ascends to the surface too rapidly, the excessive nitrogen bubbles out of the bodily fluids-much like carbon dioxide bubbles out of a soda immediately after its has been opened. This results in a painful and potentially lethal medical condition known as the bends. Why does breathing a mixture of helium and oxygen rather than air help divers to avoid getting the bends?

Accepted Answer

A) Oxygen and helium have stronger attractions for each other than they do for the blood, so less helium will be dissolved in the blood and to cause the bends. 
B) The helium is less soluble in the bodily fluids and so less dissolves for a given pressure. Upon decompression, there is less helium to "bubble out" and cause potential harm. 
C) The nitrogen in the blood will bind to helium, and so will be exhaled rather than being stuck in the blood. 
D) Helium is a smaller molecule than nitrogen, so when it bubbles out of solution, it is less painful and less harmful to the body. 
A) Oxygen and helium have stronger attractions for each other than they do for the blood, so less helium will be dissolved in the blood and to cause the bends. 
B) The helium is less soluble in the bodily fluids and so less dissolves for a given pressure. Upon decompression, there is less helium to "bubble out" and cause potential harm. 
C) The nitrogen in the blood will bind to helium, and so will be exhaled rather than being stuck in the blood. 
D) Helium is a smaller molecule than nitrogen, so when it bubbles out of solution, it is less painful and less harmful to the body.

Question 13

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 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) Cool the solution to see if there is a precipitate. 
D) As long as there are more water molecules than sugar molecules, there is a saturated solution. 
A) Add more sugar, if it dissolves, it is saturated. 
B) There will be a precipitate if the water is heated. 
C) Cool the solution to see if there is a precipitate. 
D) As long as there are more water molecules than sugar molecules, there is a saturated solution.

Question 15

Why do hot 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 16

How might you separate a mixture of sand and salt?

Accepted Answer

A) with tweezers and a magnifying glass 
B) just add water 
C) heat the mixture until one of the components melts 
D) Two of the above answers are reasonable. 
A) with tweezers and a magnifying glass 
B) just add water 
C) heat the mixture until one of the components melts 
D) Two of the above answers are reasonable.

Question 17

Which of the following statements does not describes the similarity between soaps and detergents?

Accepted Answer

A) They have a polar ionic end and a long nonpolar tail. 
B) Both dissolve oils. 
C) Both are synthetic. 
D) Both are biodegradable. 
E) Both are made from fatty acids. 
A) They have a polar ionic end and a long nonpolar tail. 
B) Both dissolve oils. 
C) Both are synthetic. 
D) Both are biodegradable. 
E) Both are made from fatty acids.

Question 18

Why aren't solar stills used in more large urban areas?

Accepted Answer

A) They take up too much space. 
B) They do not produce enough water. 
C) They require too much sunlight. 
D) They are not as efficient are reverse osmosis. 
E) all of the above 
A) They take up too much space. 
B) They do not produce enough water. 
C) They require too much sunlight. 
D) They are not as efficient are reverse osmosis. 
E) all of the above

Question 19

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 20

Which of the following solutions is the most dilute?

Accepted Answer

A) one liter of water with 1 gram of sugar 
B) one liter of water with 2 grams of sugar 
C) one liter of water with 5 grams of sugar 
D) one liter of water with 10 grams of sugar 
E) They all have the same volume. 
A) one liter of water with 1 gram of sugar 
B) one liter of water with 2 grams of sugar 
C) one liter of water with 5 grams of sugar 
D) one liter of water with 10 grams of sugar 
E) They all have the same volume.

Exam 16: Mixtures

How many grams of sugar (sucrose)are there in 5 liters of sugar water that has a concentration of 0.5 grams per liter of solution?

Does the concentration of chlorine in drinking water tend to increase or decrease as it leaves the water treatment plant and disperses into the community? Why?

Is the air in your house a homogeneous or heterogeneous mixture?

Why are noble gases infinitely soluble in noble gases?

Which of the following would be considered a homogeneous mixture?

Suggest why sodium chloride, NaCl, is insoluble in gasoline. Consider the electrical attractions.

What happens if you were to place a dilute solution that is in a bag made of a semipermeable membrane and were to then suspend it in a very concentrated solution?

Which of the following material phases cannot form a solution?

What is the easiest way to eliminate organic components?

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

Water being purified using aluminum salts and a base is an example of ________.

During osmosis ________.

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

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

How might you separate a mixture of sand and salt?

Which of the following statements does not describes the similarity between soaps and detergents?

Why aren't solar stills used in more large urban areas?

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 solutions is the most dilute?

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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