Deck 8: Water Everywhere: A Most Precious Resource

Question 1

Numbers 1 through 4 are used to identify four different elements.Based on periodic table trends,which number identifies the element that is expected to have the greatest tendency to attract a shared pair of electrons?

A)1
B)2
C)3
D)4

Answer 1

3

Question 2

How many moles of sodium chloride are there in 250 mL of a 1.20 M sodium chloride solution?

A)0.30
B)0.60
C)1.2
D)2.4

Answer 2

0.30

Question 3

The recommended daily requirement of calcium is 1,000 mg.Tap water in a Midwestern city contains approximately 150 mg Ca/L.A person living in the city who drinks two liters of water in one day would receive ________ percent of his/her RDA of calcium.

A)3
B)7.5
C)15
D)30

Answer 3

30

Question 4

What is the molarity of sodium chloride in a solution containing 0.50 mol of sodium chloride in 500 mL of water?

A)0.25 M
B)0.50 M
C)1.0 M
D)5.0 M

Question 5

Which shows the Lewis structure of water with the correct partial charges and nonbonding electrons?

A)
B)
C)
D)

Question 6

In general,hydrogen bonds are

A)about ten times stronger than typical covalent bonds.
B)about 1/10 as strong as typical covalent bonds.
C)found in every molecule containing more than one hydrogen atom.
D)found only between H atoms in molecules like H₂.

Question 7

Which molecule(s) contain(s) polar covalent bonds,but is(are) nonpolar?

A)I only
B)III only
C)II and IV only
D)I and III only

Question 8

Which best symbolizes the hydrogen bonding between two water molecules?

A)
B)
C)
D)

Question 9

If the lead concentration in water is 1 ppm,then we should be able to recover 1 mg of lead from _____ L of water.

A)0.01
B)0.1
C)1
D)10

Question 10

Which is the best definition of specific heat?

A)The quantity of heat energy that must be absorbed to cause one gram of a liquid substance to boil
B)The quantity of heat energy that must be absorbed to increase the temperature of one gram of a substance one degree Celsius
C)The boiling point of a liquid substance in degrees Celsius
D)The difference between the freezing point and the boiling point of a substance

Question 11

What percentage of Earth's water is in the oceans?

A)97 percent
B)50 percent
C)3 percent
D)0.014 percent

Question 12

Which correctly describes groundwater?

A)Any fresh water found above ground in lakes and rivers;usually needs treatment to remove harmful contaminants
B)Any water found above ground in lakes and rivers;usually free of harmful contaminants
C)Any water taken from aquifers
D)None of these choices are correct

Question 13

Hard water in parts of the Midwest may have a calcium ion concentration as high as 400 ppm.What is this calcium ion concentration when expressed as a percentage?

A)40 percent
B)4 percent
C)0.4 percent
D)0.04 percent

Question 14

The drawing shows two water molecules.Which statement is correct?

A)A: covalent bond;B: hydrogen bond;B is stronger
B)A: hydrogen bond;B: covalent bond;A is stronger
C)A: covalent bond;B: hydrogen bond;A is stronger
D)A: hydrogen bond;B: covalent bond;B is stronger

Question 15

Electronegativity

A)is a measure of an atom's attraction for an electron in a chemical bond.
B)is the total negative charge on a polyatomic anion.
C)is the same for all of the elements in a family or group.
D)decreases from left to right across a period on the periodic table.

Question 16

A student wants to prepare exactly 250 mL of a 0.500 M aqueous potassium hydroxide solution.What mass of potassium hydroxide (molar mass = 56.10 g/mol) must the student dissolve in the 250 mL of solution?

A)56.1 g
B)28.1 g
C)14.0 g
D)7.01 g

Question 17

The fact that carbon (C) is less electronegative than nitrogen (N) means that in a C - N bond,the

A)shared electrons are closer to the C atom than to the N atom.
B)shared electrons are closer to the N atom than to the C atom.
C)C atom takes the electrons from the N atom forming C¯ and N⁺.
D)N atom takes the electrons from the C atom forming C⁺ and N¯.

Question 18

A 4-L sample of water contains 80 µg of lead.What is this lead concentration,in parts per billion (ppb)?

A)20
B)80
C)320
D)500

Question 19

A polar covalent bond is created when

A)a metallic element reacts with a nonmetallic element.
B)two atoms share their bonding electrons unequally.
C)two atoms share three or more electrons.
D)two atoms of the same element form double or triple bonds.

Question 20

Which covalent bond is the most polar?

A)H - H
B)H - O
C)H - N
D)H - S

Question 21

How many joules are required to heat 2.0 L of water from 20 ^$\circ$ C to its boiling point of 100 ^$\circ$ C? The specific heat of water is 4.18 J/g. ^$\circ$ C and the density of water is 1 g/mL.

A)6.7 * 10⁵ J
B)1.7 * 10⁵ J
C)3.8 * 10⁴ J
D)6.7 * 10² J

Question 22

A 0.25 M solution of the sugar sucrose,C₁₂H₂₂O₁₁,in water is tested for conductivity using the type of apparatus shown.What do you predict will happen?

A)The bulb will not light up - sucrose is an electrolyte,but not very soluble in aqueous solution
B)The bulb will not light up - sucrose is in the molecular form in aqueous solution
C)The light bulb will shine dimly - sucrose is only partially ionized in aqueous solution
D)The light bulb will shine brightly - sucrose is highly ionized in aqueous solution

Question 23

The main reason that water supplies are chlorinated is

A)to produce gels that remove solids from the water.
B)to kill disease-causing organisms in the water.
C)to soften the water.
D)to precipitate lead salts from the water as insoluble lead chloride.

Question 24

Which statement is not true?

A)In forming a solution,the solute dissolves other substances that are called solvents
B)Water is the solvent in an aqueous solution
C)Pure water does not conduct electricity
D)Electrolytes dissolved in water produce a solution that can conduct electricity

Question 25

A 0.25 M aqueous solution of potassium chloride,KCl,is tested for conductivity using the type of apparatus shown.What do you predict will happen?

A)The bulb will not light up - KCl is a nonelectrolyte
B)The bulb will not light up - KCl is in the molecular form when dissolved in water
C)The light bulb will shine dimly - KCl is only partially ionized in aqueous solution
D)The light bulb will shine brightly - KCl is highly ionized in aqueous solution

Question 26

Which is not a form of chlorine used to disinfect water?

A)Chlorine gas
B)Chloroform
C)Sodium hypochlorite
D)Calcium hypochlorite

Question 27

When table sugar (sucrose,C₁₂H₂₂O₁₁) dissolves in water,which type(s) of attraction between water and sugar molecules occur(s)? I.hydrogen bonding
II)polar-polar interactions
III)covalent bonding

A)I and II only
B)II and III only
C)I and III only
D)I,II,and III

Question 28

Which of these is not a trihalomethane?

A)CHCl₃
B)CH₃Cl
C)CHF₃
D)CHBr₂Cl

Question 29

Which is the best representation showing a sodium cation in water?

A)
B)
C)
D)

Question 30

Which form of water disinfection continues to provide antibacterial protection after the water leaves the purification plant?

A)Chlorination
B)Ozonation
C)UV radiation
D)Filtration

Question 31

A disadvantage of ozonation over chlorination is

A)the higher cost of ozonation.
B)ozonation does not protect the water after the initial process is complete.
C)the higher cost of ozonation and ozonation does not protect the water after the initial process is complete.
D)None of these choices are correct

Question 32

The attractions between anions and cations throughout a crystal are known collectively as

A)covalent bonds.
B)polar covalent bonds.
C)hydrogen bonds.
D)ionic bonds.

Question 33

We cannot effectively clean nonpolar substances from our hands or clothing with water alone;we must add soap or detergent.The structure of a typical soap molecule is shown below.Which region of this molecule would dissolve in a nonpolar substance such as grease?

A)Region 1
B)Region 2
C)Region 3
D)Region 4

Question 34

Which compounds are not soluble in water at room temperature?

A)I and II only
B)II and III only
C)III and IV only
D)I and IV only

Question 35

Which compound should be the most soluble in water?

A)
B)
C)
D)

Question 36

When the ________ molecules of ethanol,C₂H₅OH,are added to water,the ethanol molecules ________.

A)nonpolar;are attracted to the nonpolar water molecules
B)polar;form hydrogen bonds with the polar water molecules
C)polar;form covalent bonds with the polar water molecules
D)nonpolar;are not attracted to the polar water molecules

Question 37

Water has one of the highest specific heats of any known liquid.This means that the temperature of a water sample ________ with the input of a ________ amount of energy.

A)decreases greatly;small
B)decreases only slightly;large
C)increases only slightly;large
D)increases greatly;small

Question 38

What are the major disadvantages of using ozone instead of chlorine to disinfect water?

A)Ozonation is more expensive than chlorination and ozone leaves an odor in the water
B)Ozonation causes trihalomethane formation and leaves an odor in the treated water
C)Ozonation causes trihalomethane formation and is more expensive than chlorination
D)Ozone decomposes quickly and does not provide long-term protection against possible contamination as the water is piped through a municipal distribution system

Question 39

Which compound is insoluble in water?

A)Sodium carbonate
B)Potassium nitrate
C)Ammonium chloride
D)Calcium carbonate

Question 40

Which is not a consequence of hydrogen bonding between water molecules?

A)Water has a high boiling point
B)Ice floats on water
C)Water has a high specific heat
D)Water is colorless and odorless

Question 41

The hydronium ion concentration in a solution with pH 10 is ________ than the hydronium ion concentration in a solution with pH 13.

A)1,000 times less
B)3 times greater
C)1,000 times greater
D)100 times less

Question 42

The drawing shows a simple way of purifying salt water.What is this process called?

A)Filtration
B)Distillation
C)Ozonation
D)Chlorination

Question 43

The pH of lemon juice is approximately 2.40.At this pH,the hydronium ion concentration is closest to which concentration?

A)2.5 * 10¯¹² M
B)4.0 * 10¯³ M
C)0.38 M
D)5.6 * 10¯⁴ M

Question 44

Evaluate the ratio M_H+ (pH 3) / M_H+ (pH 7).

A)0.0001
B)0.001
C)0.429
D)10,000

Question 45

Which of the following is not a consequence of biomagnification?

A)Consumption of tuna should be limited
B)DDT from fish was killing large birds before the pesticide was banned
C)Lead in water can lead to brain damage in children
D)Polar compounds are found in high concentrations in predator animals

Question 46

Which of the following are methods of making sea water appropriate for drinking? (More than one choice may be appropriate. )

A) Osmosis
B)Reverse Osmosis
C)Distillation
D)Flocculation

Question 47

What is biological oxygen demand (BOD)?

A)A measure of the amount of dissolved oxygen microorganisms use up as they decompose organic wastes found in water
B)A measure of the amount of dissolved oxygen necessary to purify wastewater
C)A measure of the phosphate ion concentration of water
D)A measure of nitrate ion concentration of water

Question 48

Which chemical equation shows the dissociation of two protons from trihydrogen phosphate (phosphoric acid)?

A)H₃PO₄ $\rarr$ H ₂⁺+ HPO₄¯
B)H₃PO₄ $\rarr$ H ₂²⁺+ PO₄ ²¯
C)H₃PO₄ $\rarr$ 2H⁺ + HPO₄ ¯
D)H₃PO₄ $\rarr$ H ₃³⁺ + PO₄^3¯

Question 49

Which chemical equation shows the dissociation of magnesium hydroxide?

A)Mg(OH)₂ $\rarr$ Mg²⁺ + 2OH¯
B)MgOH $\rarr$ Mg²⁺ + OH^2¯
C)Mg(OH)₃ $\rarr$ Mg³⁺ + 3OH¯
D)Mg(OH)₂ $\rarr$ Mg²⁺ + H₂O + O^2-

Question 50

Reverse osmosis is illustrated in this diagram.What is this process used for?

A)To purify water by ion exchange
B)To remove dissolved salts from sea water
C)For the ozonation of water supplies
D)To add fluorine to municipal water supplies

Question 51

The world map shows the availability of safe drinking water around the world.Which statement is true?

A)In Australia,less than 75 percent of the population has access to safe drinking water
B)In most of Africa,more than 90 percent of the population has access to clean water
C)In Europe and Russia,more than 10 percent of the population does not have access to clean water
D)In the United States and Canada,more than 90 percent of the population has access to clean water

Question 52

When dissolved in water,hydrogen bromide (HBr) forms hydrobromic acid.Determine the hydroxide ion concentration in a 4,500 mL solution containing 3.78 g hydrogen bromide;K = 1.00 * 10¯¹⁴.

A)[OH¯] = 9.63 * 10^-13 M
B)[OH¯] = 2.14 *10^-13 M
C)[OH¯] = 4.67 *10 10_-2 M
D)[OH¯] = 0.0104 M

Question 53

Mixing which of the following will produce a precipitation reaction (give an insoluble product)?

A)HNO₃ (aq) and Sr(OH)₂(aq)
B)LiNO₃ and NaI
C)Na₂SO₄(aq) and Ba(OH)₂(aq)
D)NaOH and KBr

Question 54

Which concentration is consistent with a basic solution?

A)M_H+ = 3.2 * 10^-3 M
B)M_OH- = 3.6 * 10^-9 M
C)M_H+ = 9.7 * 10^-4 M
D)M_OH- = 3.4 * 10^-3 M

Question 55

Why is water a liquid a room temperature instead of a gas?

A)It is a gas a room temperature
B)Water has hydrogen bonds between the molecules
C)Water is very acidic
D)Water is a good solvent

Question 56

A proton released by an acid in aqueous solution quickly reacts with water to form a hydronium ion.What product is formed when a proton reacts with ammonia (NH₃)?

A)NH₃⁺
B)NH₄
C)NH₂^¯
D)NH₄⁺

Question 57

Which type of water may be considered pure?

A)Bottled water
B)Filtered water
C)Distilled water
D)Chlorinated water

Question 58

At water treatment plants aluminum sulfate and calcium hydroxide are added to

A)neutralize excess ozone.
B)neutralize excess chlorine.
C)remove suspended clay and dust particles.
D)neutralize excess acidity or basicity.

Question 59

What atmospheric component is responsible for the natural acidity of rain?

A)Nitrogen
B)Ozone
C)Oxygen
D)Carbon dioxide

Question 60

Calculate the pH of a solution prepared by dissolving 1.2 g of potassium hydroxide (KOH) in 1,250 mL of water.

A)0.017
B)1.77
C)9.22
D)12.23

Question 61

The acid neutralizing capacity of a lake or stream most often derives from the presence of ________ in the surrounding soil or rock.

A)CaCO₃
B)HNO₃
C)NaCl
D)Sr(OH)₂

Question 62

Which reaction accounts for the fact that the pH of rain is naturally slightly acidic?

A)CO₂ + H₂O $\rarr$ H⁺ + HCO₃¯
B)SO₃ + H₂O $\rarr$ 2 H⁺ + SO₄^2¯
C)Ca²⁺ + CO₂ + H₂O $\rarr$ CaCO₃ + 2 H⁺
D)NO₂ + H₂O $\rarr$ 2 H⁺ + NO₃¯

Question 63

Which of the following is not carried out by bacteria in soil?

A)Atmospheric nitrogen is fixed in soils
B)Ammonium is converted into nitrites
C)Nitrites are converted to nitrates
D)All of these are carried out by bacteria

Question 64

Which solution is acidic?

A)M_OH¯ = 0.0065 M
B)M_H+ = 1.27 * 10¯⁹ M
C)M_H+ = 5.79 * 10¯¹⁰ M
D)M_OH¯ = 1.77 * 10¯¹⁰ M

Question 65

The pH of rain water falling through an unpolluted atmosphere is closest to

A)4.7.
B)5.4.
C)7.0.
D)8.7.

Question 66

Most aquatic life in lakes cannot survive in water with a pH less than

A)9.
B)8.
C)6.
D)5.

Question 67

Every increase of one pH unit indicates

A)an increase in acidity.
B)10 times more hydrogen ions in solution.
C)10 times less hydrogen ions in solution.
D)None of these choices are correct

Question 68

Lakes surrounded by ________ have very little acid-neutralizing capacity. I.marble
II)granite
III)limestone

A)I only
B)II only
C)I and III only
D)II and III only

Question 69

Which of the following is a weak base?

A)HCl
B)NaOH
C)NH₃
D)LiOH

Question 70

Bases produce which ions in aqueous solution?

A)OH¯
B)NO₂¯
C)Cl¯
D)SO₃¯

Question 71

Which reaction most accurately represents the dissociation of nitrous acid (HNO₂) in water?

A)HNO₂ + H₂O $\rarr$ H₃O⁺ + NO₂¯
B)HNO₂ + H₂O $\rarr$ H₃O₂⁺ + NO¯
C)HNO₂ + H₂O $\rarr$ HN + HO⁺ + HO₂¯
D)HNO₂ + H₂O $\rarr$ H₃O⁺ + N + O₂¯

Question 72

Bases are substances that increase the hydroxide ion concentration in aqueous solution.Why does ammonia (NH₃),which does not contain a hydroxide group,act as a base?

A)Ammonia acts as a base only in the presence of hydroxide ion-containing compounds
B)Ammonia molecules remove protons from water molecules,forming hydroxide ions
C)Ammonia molecules donate protons to water molecules,forming hydroxide ions
D)Ammonia acts as a base only in the presence of very strong acids

Question 73

Scientists predict that shells of some ocean creatures will start to dissolve after how many more years of ocean acidification?

A)40 years
B)150 years
C)300 years
D)85 years

Question 74

What is the concentration of hydroxide ions in an aqueous solution containing [H⁺] = 1 x 10^-5 M?

A)1 x 10^-5 M
B)1 x 10^-7 M
C)1 x 10^-9 M
D)1 x 10^-14 M

Question 75

An acidic fog in Pasadena was found to have a pH of 2.50.Which expression represents this pH measurement?

A)M_OH¯ = 3.2 * 10¯¹² M
B)M_OH¯ = 3.2 * 10¯⁹ M
C)M_H+ = 9.7 * 10¯³ M
D)M_H+ = 2.5 M

Question 76

Predict the products of this reaction: KOH + HNO₃ $\rarr$

A)KNO₃ + H₂O
B)KNO₂ + H₂O₂
C)KH + HNO₄
D)KO₄ + H₂N

Question 77

Which reaction represents an acid-base neutralization reaction?

A)HNO₂ + H₂O $\rarr$ H₃O⁺ + NO₂¯
B)NaOH + H₂O $\rarr$ H₃O⁺ + N_aO¯
C)Ba(OH)₂ + 2LiCl $\rarr$ BaCl₂ + 2LiOH
D)Be(OH)₂ + H₂SO₄ $\rarr$ BeSO₄ + 2H₂O

Question 78

Predict the products of the chemical equation: 3 LiOH + H₃PO₄ $\rarr$

A)3 LiH + (OH)₃PO₄
B)3 H + 3 O₂ + H₃Li₃
C)Li₃PO₄ + 3 H₂O
D)Li₃P + 2 H₂O + H₃O₅

Question 79

Which substance has the highest pH?

A)Orange juice
B)Rain
C)A sulfuric acid solution
D)A lye solution