Deck 16: Mixtures

Question 1

How would you classify the following material? coffee (black)

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

Answer 1

C

Question 2

Half-frozen fruit punch is always sweeter than the same fruit punch completely melted because

A)the sugar sinks to the bottom.
B)crystallization is a purifying process.
C)the half-frozen fruit punch is warmer.
D)sugar molecules are less soluble in a half-frozen solution.

Answer 2

B

Question 3

How would you classify the following material? milk

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

Answer 3

A

Question 4

What is the difference between a compound and a mixture?

A)A mixture can be physically separated into its components; a compound cannot be physically separated into its components.
B)A compound can be physically separated into its components; a mixture cannot be physically separated into its components.
C)A compound is just a mixture of elements.
D)The components of a mixture do not have the same properties individually as they do when mixed.
E)The components of a compound have the same properties individually as they do when mixed.

Question 5

Which of the following is a pure substance?

A)baking soda
B)salt water
C)cooking oil
D)duct tape
E)orange juice

Question 6

Which of the following would be considered a homogeneous mixture?

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

Question 7

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

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 8

When blue food coloring is stirred into water, the result is a ________.

A)homogeneous mixture called a solution
B)homogeneous mixture called a suspension
C)heterogeneous mixture called a solution
D)heterogeneous mixture called a suspension
E)pure liquid

Question 9

Each circle represents an atom. Which of the following boxes contains an element? A compound? A mixture?

A)element: A, C; compound: A, B, C; mixture: A, B
B)element: C; compound: A, B; mixture: B
C)element: A, C; compound: A, B; mixture: A
D)element: A, C; compound: A, B; mixture: A, B

Question 10

How would you classify the following material? swimming pool water

A)homogeneous mixture
B)heterogeneous mixture
C)a pure element
D)a pure compound
E)depends on how many children have been in it

Question 11

How might you separate a mixture of sand and salt?

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 12

What is the difference between a compound and a mixture?

A)They both consist of atoms from different elements.
B)The way in which their atoms are bonded together.
C)One is a solid and the other is a liquid.
D)The components of a mixture are not chemically bonded together.

Question 13

Which of the following would be considered a heterogeneous mixture?

A)salad dressing
B)water
C)milk
D)vegetable oil
E)vinegar

Question 14

Which of the following is a mixture?

A)air
B)gold
C)salt
D)iron
E)helium

Question 15

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?

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 16

A combination of two or more substances in which they no longer retain their chemical properties is called a(n)________.

A)mixture
B)compound
C)heterogeneous mixture
D)periodic trend
E)suspension

Question 17

The following image represents which kind of matter?

A)a mixture
B)a compound
C)an element
D)none of the above
E)all of the above

Question 18

Many dry cereals are fortified with iron, which is added to the cereal in the form of small iron particles. How might these particles be separated from the cereal?

A)add water and the iron particles will float to the top
B)blend the cereal to a fine consistency and pass through a filter
C)collect the iron filings with a magnet
D)heat the cereal so that the iron particles melt and thereby coalesce

Question 19

If you filter sea water to remove all of the particles you would be left with a clear ________.

A)homogeneous mixture called a solution
B)homogeneous mixture called a suspension
C)heterogeneous mixture called a solution
D)heterogeneous mixture called a suspension
E)pure liquid

Question 20

The following image represents which kind of matter?

A)a compound
B)a mixture
C)an element
D)none of the above
E)all of the above

Question 21

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

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 22

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

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

Question 23

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

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 24

Which of the following describes the term concentration?

A)It is what you are doing now to answer this question.
B)It is the amount of solute in a given amount of solution.
C)It is the amount of solvent in a given amount of solution.
D)It is the given amount of solution in a given container.
E)It is the given amount of solvent per amount of solute.

Question 25

Classify the following as element, compound, or mixture, and justify your classifications: table salt, stainless steel, table sugar, aluminum, ice.

A)mixture; element; compound; element; element
B)compound; mixture; compound element; compound
C)mixture; compound; mixture; element; compound
D)compound; element; compound; element; compound

Question 26

What can be said about drinking water that is 99.9999 percent free of some poison, such as a pesticide?

A)In each 10,000 parts of the contaminated water there is one part pesticide and 9999 parts pure water.
B)In each 100,000 parts of the contaminated water there is one part pesticide and 99,999 parts pure water.
C)The ratio of water molecules to pesticide molecules in the glass is so great that drinking the water is not problematic.
D)The water is highly contaminated and surely not fit to drink.

Question 27

Which of the following solutions is the most dilute?

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.

Question 28

Which of the following solutions is the most concentrated?

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.

Question 29

How would you classify the following material? coffee (with milk)

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

Question 30

A sample of water that is 99.9999 percent pure contains 0.0001 percent impurities. Consider from Chapter 1 that a glass of water contains on the order of a trillion trillion (1 × 10²⁴)molecules. If 0.0001 percent of these molecules were the molecules of some impurity, about how many impurity molecules would this be?

A)1000 (one thousand: 1 × 10³)
B)1,000,000 (one million: 1 × 10⁶)
C)1,000,000,000 (one billion: 1 × 10⁹)
D)1,000,000,000,000,000,000 (one million trillion: 1 × 10¹⁸)

Question 31

What do chicken noodle soup and garden soil have in common?

A)They are both examples of heterogeneous mixtures.
B)They both contain elements.
C)They are both examples of compounds.
D)nothing

Question 32

In a solution of 77 percent nitrogen and 23 percent oxygen, which is the solvent?

A)nitrogen
B)oxygen
C)both
D)neither
E)Gases cannot form solutions.

Question 33

Which of the following solutions is the most dilute?

A)0.1 liter of water with 1 gram of sugar
B)0.2 liter of water with 2 grams of sugar
C)0.5 liter of water with 5 grams of sugar
D)1 liter of water with 10 grams of sugar
E)They all have the same concentration.

Question 34

Read carefully. Twice as much as one million trillion is two million trillion. One thousand times as much is 1000 million trillion. One million times as much is 1,000,000 million trillion, which is the same as one trillion trillion. Thus, one trillion trillion is a million times greater than a million trillion. Got that? So how many more water molecules than impurity molecules are there in a glass of water that is 99.9999 percent pure?

A)1000 (one thousand: 1 × 10³)more water molecules than impurities molecules
B)1,000,000 (one million: 1 × 10⁶)more water molecules than impurities molecules
C)1,000,000,000 (one billion: 1 × 10⁹)more water molecules than impurities molecules
D)1,000,000,000,000,000,000 (one million trillion: 1 × 10¹⁸)more water molecules than impurities molecules

Question 35

Which of the following statements describes a saturated solution?

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 36

Someone argues that he or she doesn't drink tap water because it contains thousands of molecules of some impurity in each glass. How would you respond in defense of the water's purity, if it indeed does contain thousands of molecules of some impurity per glass?

A)Impurities aren't necessarily bad, in fact, they may be good for you.
B)The water contains water molecules and each water molecule is pure.
C)There's no defense. If the water contains impurities it should not be drunk.
D)Compared to the billions and billions of water molecules, a thousand molecules of something else is practically nothing.

Question 37

Which of the following material phases cannot form a solution?

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

Question 38

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

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

Question 39

How does a suspension differ from a solution?

A)A suspension is a heterogeneous mixture whose components can be separated by simple filtration. A solution is a homogeneous mixture which cannot be separated by simple filtration.
B)A suspension is a heterogeneous mixture consisting of different phases whereas a solution is a homogeneous mixture consisting of a single phase.
C)Although a solution and suspension are both homogeneous mixtures, only the components of a suspension will separate by spinning the mixture in a centrifuge.
D)The difference between a suspension and a solution can only be determined by chemical means.

Question 40

A sample of steel is composed of 5 percent carbon and 95 percent iron. Which is the 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 41

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?

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

Question 42

How many molecules of sucrose are in 0.5 L of a 2 molar solution of sucrose?

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 43

Which of the following best describes a two-molar sucrose solution?

A)one liter of solution that contains 2 moles of sucrose
B)one liter of solution that contains 2 moles of water
C)one liter of solution that contains 6.02 × 10²³ molecules of sucrose
D)two liters of solution that contains 1 mole of sucrose
E)one mole of sucrose dissolved in 2 liters of solution

Question 44

If you need 3.01 × 10²³ molecules of sucrose, how many liters of a 4.00 molar solution would you need?

A)0.125 L
B)0.250 L
C)4.00 L
D)1.00 L
E)none of the above

Question 45

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

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

Question 46

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

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

Question 47

How many moles of sugar, C₁₂H₂₂O₁₁, are there in 200. grams?

A)0.585 moles
B)68,400 moles
C)1.71 moles
D)0.684 moles

Question 48

What is the sum of the atomic masses of all the atoms in sucrose, C₁₂H₂₂O₁₁?

A)342 amu
B)182 amu
C)270 amu
D)none of the above

Question 49

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?

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

Question 50

Which has the most atoms?

A)a mole of gold
B)a mole of helium
C)a mole of lead
D)All of the above have the same number of atoms.
E)none of the above

Question 51

What statement best describes a mole?

A)a little furry mammal that lives in the ground
B)a very small number chemists use to count atoms or molecules
C)the amount of molecules or atoms in 1 gram of something
D)It is a very large number chemists use to count atoms or molecules.
E)none of the above

Question 52

Which of the following solutions is the most concentrated?

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 53

What is molarity?

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 54

How many moles of water are there in 100. grams of water?

A)1800 moles
B)100 moles
C)0.018 moles
D)5.55 moles

Question 55

Many solvents expand to occupy greater volumes with increasing temperature. What happens to the concentration of a solution made with such a solvent as its temperature is increased?

A)Since concentration depends on how much mass is dissolved in a given volume, as the volume increases, the concentration decreases.
B)The concentration of a solution increases as the solute fits into the new spaces between the molecules.
C)Since it has a greater ability to dissolve more solute at a higher temperature, its concentration has decreased.
D)Since it has a greater ability to dissolve more solute at a higher temperature, its concentration has increased.

Question 56

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?

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

Question 57

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

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 58

What is the molarity of 0.5 liters of a solution with five moles of sucrose in it?

A)10 molar
B)0.5 molar
C)5 molar
D)2.5 molar
E)1 molar

Question 59

How many molecules of sucrose are in 0.5 L of a 1 molar solution of sucrose?

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 60

Which of the following solutions is the most concentrated?

A)0.1 liter of water with 1 gram of sugar
B)2 liters of water with 0.2 gram of sugar
C)0.5 liter of water with 50 grams of sugar
D)3 liters of water with 30 grams of sugar
E)They all have the same concentration.

Question 61

Why are noble gases infinitely soluble in noble gases?

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 62

Why does oxygen have such a low solubility in water?

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 63

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

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

Question 64

Based on atomic size, which would you expect to be more soluble in water: helium, He, or nitrogen, N₂?

A)Although He is smaller, its outer orbital is filled and the atom will have little attraction to the water molecules.
B)Since He atoms are smaller, more of them can fit into solution, so it has a higher solubility in water.
C)Nitrogen atoms are bigger and so nitrogen molecules should be more soluble in water due to greater dipole-induced dipole attractions.
D)He atoms are bigger and so helium molecules should be more soluble in water due to greater dipole-induced dipole attractions.

Question 65

Why does oxygen have such a low solubility in water?

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 66

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

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 67

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

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 68

How is the solubility of a gas affected by temperature?

A)As temperature goes up, the solubility goes up.
B)As temperature goes down, the solubility goes down.
C)As temperature goes up, the solubility stays the same.
D)As temperature goes down, the solubility goes up.
E)both A and B

Question 69

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

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

Question 70

Describe what usually happens to a hot solution that is saturated with a solid as it cools.

A)The solid that is dissolved comes out of the solution completely.
B)The solid stays in the solution.
C)Some of the solid comes out of the solution.
D)The solution freezes.
E)The solution solidifies.

Question 71

How are intermolecular forces and solubility related?

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 72

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

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 73

If the solubility of a compound is 72 grams per liter, how many grams of the compound will dissolve in 0.50 liters?

A)36 g
B)72 g
C)144 g
D)30 g
E)none of the above

Question 74

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?

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

Question 75

If nitrogen, N₂, were pumped into your lungs at high pressure, what would happen to its solubility in your blood stream?

A)The greater the pressure, the greater the solubility.
B)The greater the pressure, the lower the solubility.
C)You cannot change solubility of a substance by changing the pressure.
D)Nitrogen is not soluble in your blood.

Question 76

A solid has a solubility at room temperature of 78 grams per liter. If 1.0 L of a hot solution containing 100. g of solute is cooled to room temperature, how much solid is formed?

A)22 g
B)100 g
C)78 g
D)1 L
E)78g/L

Question 77

Under which of the following conditions would you expect the highest solubility of oxygen gas in water?

A)high temperature and low O₂ pressure above the solution
B)low temperature and high O₂ pressure above the solution
C)low temperature and low O₂ pressure above the solution
D)high temperature and high O₂ pressure above the solution
E)The O₂ solubility is independent of temperature and pressure.

Question 78

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?

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 79

What property primarily determines the effect of temperature on the solubility of gas molecules?

A)the kinetic energy of the gas
B)the polarity of the gas
C)the molecular weight of the gas
D)the ionic strength of the gas
E)the dipole strength of the solvent

Question 80

How is the solubility of a solid affected by temperature?

A)As temperature goes up, the solubility goes up.
B)As temperature goes down, the solubility goes down.
C)As temperature goes up, the solubility goes down.
D)As temperature goes down, the solubility goes up.
E)both A and B