Quiz 18: Two Classes of Chemical Reactions
Physics & Astronomy
Q 1Q 1
How do you make a proton out of a hydrogen atom?
A)remove an electron from a hydrogen atom
B)remove a proton from a helium nucleus
C)let the hydrogen atoms undergo fusion
D)let the hydrogen atoms combine to form a hydrogen molecule and eject an electron
E)let the hydrogen atoms combine to form a hydrogen molecule and eject a proton
Free
Multiple Choice
A
Q 2Q 2
Which of the following compounds would least likely act as an acid?
A)SO4-2
B)HSO4-1
C)H2SO4
D)NH3
E)CH3CO2H
Free
Multiple Choice
A
Q 3Q 3
What is an acid?
A)anything that donates hydrogen ions
B)anything that accepts hydrogen atoms
C)anything that donates hydrogen atoms
D)anything that dissolves metal
E)anything that donates hydronium ions
Free
Multiple Choice
A
Q 4Q 4
What is a base?
A)anything that accepts a hydrogen ion
B)anything that accepts a hydroxide ion
C)anything that donates a hydroxide ion
D)anything that can be used to clean drains
E)anything with a bitter taste
Free
Multiple Choice
Q 5Q 5
What best describes what happens when an acid such as HCl is mixed with water?
A)The proton chemically bonded to the chlorine is transferred to a water molecule and forms a chloride ion and a hydronium ion.
B)A proton from the chlorine nucleus is ejected and captured by a water molecule to form a negatively charged HCl and a new hydronium ion.
C)A hydroxide ion from the water is transferred to the HCl molecule to form a proton and hydronium ion.
D)HCl is not an acid.
E)none of the above
Free
Multiple Choice
Q 6Q 6
According to the following reaction,which molecule is acting as an acid? H2O + H2SO4 → H3O+ + HSO4-
A)H2SO4
B)H2O
C)H3O+
D)HSO4-
E)none of the above
Free
Multiple Choice
Q 7Q 7
According to the following reaction,which molecule is acting as a base? H2O + H2SO4 → H3O+ + HSO4-
A)H2SO4
B)H2O
C)H3O+
D)HSO4-
E)none of the above
Free
Multiple Choice
Q 8Q 8
According to the following reaction,which molecule is acting as an acid? H3O+ + HSO4- → H2O + H2SO4
A)H2SO4
B)H2O
C)H3O+
D)HSO4-
E)none of the above
Free
Multiple Choice
Q 9Q 9
According to the following reaction,which molecule is acting as a base? H3O+ + HSO4- → H2O + H2SO4
A)H2SO4
B)H2O
C)H3O+
D)HSO4-
E)none of the above
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Multiple Choice
Q 10Q 10
According to the following reaction,which molecule is acting as a base? H2O + NH3 → OH- + NH4+
A)H2O
B)NH3
C)OH-
D)NH4+
E)none of the above
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Multiple Choice
Q 11Q 11
According to the following reaction,which molecule is acting as an acid? H2O + NH3 → OH- + NH4+
A)H2O
B)NH3
C)OH-
D)NH4+
E)none of the above
Free
Multiple Choice
Q 12Q 12
According to the following reaction,which molecule is acting as an acid? OH- + NH4+ → H2O + NH3
A)H2O
B)NH3
C)OH-
D)NH4+
E)none of the above
Free
Multiple Choice
Q 13Q 13
According to the following reaction,which molecule is acting as a base? OH- + NH4+ → H2O + NH3
A)H2O
B)NH3
C)OH-
D)NH4+
E)none of the above
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Multiple Choice
Q 14Q 14
In the reaction below,what does the symbol ⇌ mean? OH- + NH4+ ⇌ H2O + NH3
A)It means that the forward and backward reactions are happening at the same time.
B)It means that the reaction cannot decide which way to go.
C)It means that the forward reaction does not progress.
D)It means that the backward reaction happens as fast as the forward reaction and so the proton is not transferred at all.
E)none of the above
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Multiple Choice
Q 15Q 15
For the following reaction,identify whether the compound in bold is behaving as an acid or a base. H3PO4 + H2O ⇌ H2PO4- + H3O+
A)acid
B)base
C)neither
D)both
E)none of the above
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Multiple Choice
Q 16Q 16
For the following reaction,identify whether the compound in bold is behaving as an acid or a base. H3PO4 + H2O ⇌ H2PO4- + H3O+
A)acid
B)base
C)neither
D)both
E)none of the above
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Multiple Choice
Q 17Q 17
For the following reaction,identify whether the compound in bold is behaving as an acid or a base. H3PO4 + H2O ⇌ H2PO4- + H3O+
A)acid
B)base
C)neither
D)both
E)none of the above
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Multiple Choice
Q 18Q 18
For the following reaction,identify whether the compound in bold is behaving as an acid or a base. H3PO4 + H2O ⇌ H2PO4- + H3O+
A)acid
B)base
C)neither
D)both
E)none of the above
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Multiple Choice
Q 19Q 19
For the following acid-base reaction,identify which salt is formed. HCl + NaOH ⇌ ???? + H2O
A)NaCl
B)H3OCl
C)NaOH2
D)NaOH2Cl
E)none of the above
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Multiple Choice
Q 20Q 20
For the following acid-base reaction,identify what compound is formed in the space marked. HCl + KOH ⇌ ???? + H2O
A)KCl
B)H3OCl
C)KOH2
D)KOH2Cl
E)none of the above
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Multiple Choice
Q 21Q 21
For the following acid-base reaction,identify what is formed in the space marked. HF + KOH ⇌ ???? + H2O
A)KF
B)H3OF
C)KOH2
D)KOH2F
E)none of the above
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Multiple Choice
Q 22Q 22
For the following acid-base reaction,identify what compound is formed in the space marked. HNO3 + KOH ⇌ ???? + H2O
A)KNO3
B)H3ONO3
C)KOH2
D)KOH2NO3
E)none of the above
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Multiple Choice
Q 23Q 23
For the following acid-base reaction,identify what is formed in the space marked. H2SO4 + KOH ⇌ KHSO4 + ???
A)K2SO4
B)H3OSO4
C)H2O
D)KOH2SO4
E)none of the above
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Multiple Choice
Q 24Q 24
Which of the following statements is not true about a neutralization reaction?
A)Water is always formed in a neutralization reaction.
B)One molecule of acid neutralizes one molecule of base.
C)A neutralization is the reaction of a hydroxide ion with a proton.
D)All of the above are true.
E)None of the above are true.
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Multiple Choice
Q 25Q 25
Suggest why people once washed their hands with ashes.
A)The ashes act as a base and reacts with skin oils to produce solutions of soap.
B)The ashes act as an acid and reacts with the skin oils to produce soap.
C)The oils on the skin act as a base and reacts with the ashes to produce soap.
D)After being burnt in the fire,the acids and bases of the log are neutralized,making it a gentle material to use on the hands.
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Multiple Choice
Q 26Q 26
What is the relationship between the hydroxide ion and a water molecule?
A)A hydroxide ion is a water molecule plus a proton.
B)A hydroxide ion and a water molecule are the same things.
C)A hydroxide ion is a water molecule minus a hydrogen nucleus.
D)A hydroxide ion is a water molecule plus two extra electrons.
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Multiple Choice
Q 27Q 27
An acid and a base react to form a salt,which consists of positive and negative ions.Which forms the positive ions: the acid or the base? Which forms the negative ions?
A)The acid forms the positive ion,the base forms the negative ion.
B)The acid forms the negative ion,the base forms the positive ion.
C)Because different substances can act as an acid or a base,it depends on the substance you begin with.
D)all of the above
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Multiple Choice
Q 28Q 28
Water is formed from the reaction of an acid and a base.Why is it not classified as a salt?
A)Not all acid base reactions produce a salt,as in the case with the formation of water.
B)The attraction between the two ions in water molecules are too strong.
C)By definition,a salt must be able to dissolve in water,so water itself cannot be called a salt.
D)A salt is an ionic compound,whereas water is a covalent compound.
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Multiple Choice
Q 29Q 29
Identify the acid or base behavior of each substance in these reactions: + ⇌ O + HCl
A) acts as an acid, acts as a base, O acts an acid,HCl acts as a base.
B) acts as an base, acts as a acid, O acts an acid,HCl acts as a base.
C) acts as an acid, acts as a base, O acts an base,HCl acts as a acid.
D) acts as an base, acts as a acid,
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Multiple Choice
Q 30Q 30
Identify the acid or base behavior of each substance in these reactions: HSO4- + O ⇌ O + S
A)HSO4- acts as an acid, O acts as a base,O acts as an acid, S acts as a base.
B)HSO4- acts as an base, O acts as a acid,O acts as an acid, S acts as a base.
C)HSO4- acts as an acid, O acts as a base,O acts as an base, S acts as a acid.
D)HSO4- acts as an base, O acts as a acid,O acts as an base, S
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Multiple Choice
Q 31Q 31
What happens to the corrosive properties of an acid and a base after they neutralize each other? Why?
A)The corrosive properties are neutralized because the acid and base no longer exist.
B)The corrosive properties are unaffected because salt is a corrosive agent.
C)The corrosive properties are doubled because the acid and base are combined in the salt.
D)The corrosive properties remain the same when the salt is mixed into water.
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Multiple Choice
Q 32Q 32
The main component of bleach is sodium hypochlorite,NaOCl,which consists of sodium ions,Na⁺,and hypochlorite ions, What products are formed when this compound is reacted with the hydrochloric acid,HCl,of toilet bowl cleaner?
A)The products are NaCl, ,and .
B)The products are NaOH, O,and .
C)The products are NaCl and HOCl.
D)The products are NaOH, ,and
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Multiple Choice
Q 33Q 33
Which of the following statements about strong or weak acids is true?
A)A weak acid and a strong acid at the same concentration are equally corrosive.
B)A weak acid readily forms ions when dissolved in water.
C)A strong acid will never react with a strong base.
D)A weak acid will react with a strong base.
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Multiple Choice
Q 34Q 34
Which of the following statements about strong or weak bases is true?
A)A weak base completely separates into ions in water.
B)A weak base will not react with a strong acid.
C)A strong base is always corrosive.
D)A strong base will readily accept protons from even weak acids.
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Multiple Choice
Q 35Q 35
What is the main characteristic of a strong acid?
A)It is completely dissociated in water.
B)It readily gives up its proton to a base.
C)It is corrosive.
D)It will damage your skin.
E)all of the above
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Multiple Choice
Q 36Q 36
What is the main characteristic of a strong base?
A)It is completely dissociated in water.
B)It readily accepts an acidic proton.
C)It is corrosive.
D)It will damage your skin.
E)all of the above
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Multiple Choice
Q 37Q 37
Which of the following statements about strong and weak acids is not true?
A)A weak acid is as corrosive as a strong acid.
B)A weak acid dissociates in water.
C)A strong acid will react with a strong base.
D)A weak acid will react with a strong base.
E)All of the above are untrue.
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Multiple Choice
Q 38Q 38
Which of the following statements about strong and weak bases is not true?
A)A weak base does not completely dissociate in water.
B)A weak base will not react with a strong acid.
C)A strong base can be extremely corrosive.
D)A strong base will readily accept protons from even weak acids.
E)All of the above are untrue.
Free
Multiple Choice
Q 39Q 39
-Which of the above images best depicts a water solution of a weak acid (represented by HA)?
A)A
B)B
C)C
D)All of the above are weak acids.
E)None of the above are weak acids.
Free
Multiple Choice
Q 40Q 40
-Which of the above images represents a solution of the strongest acid (HA)?
A)A
B)B
C)C
D)All of the above are strong acids.
E)None of the above are strong acids.
Free
Multiple Choice
Q 41Q 41
Arrange the following images of an aqueous base solution in order of increasing base strength:
A)A,B,C
B)B,C,A
C)C,B,A
D)A,C,B
E)All are equally strong.
Free
Multiple Choice
Q 42Q 42
Sodium hydroxide,NaOH,is a strong base,which means that it readily accepts hydrogen ions.What products are formed when sodium hydroxide accepts a hydrogen ion from a water molecule?
A)water and sodium hydroxide
B)sodium hydroxide and hydronium ions
C)sodium ions and hydronium ions
D)sodium ions and water
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Multiple Choice
Q 43Q 43
A weak acid is added to a concentrated solution of hydrochloric acid.Does the solution become more or less acidic?
A)More acidic,since there are more hydronium ions being added to the solution.
B)Less acidic,since the solution becomes more dilute with a less concentrated solution of hydronium ions being added to the solution.
C)No change in acidity,since the concentration of the hydrochloric acid is too high to be changed by the weak solution.
D)Less acidic since the concentration of hydroxide ions will increase.
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Multiple Choice
Q 44Q 44
Which of the following reactions illustrates an amphoteric compound?
A)2 HF ⇌ H2F+ + F-
B)NaOH + HBr ⇌ NaBr + H2O
C)2 H2 + O2 ⇌ 2 H2O
D)All are amphoteric.
E)none of the above
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Multiple Choice
Q 45Q 45
What do the brackets in the following equation represent? [H3O+] × [OH-] = Kw
A)The brackets mean the molarity of the compound inside them.
B)The molecule inside does not react with the other molecules in brackets.
C)The molecule in brackets is undergoing hydrogen bonding with the other molecule in brackets.
D)The first molecule in brackets is an acid and it reacts with the second molecule in brackets,which is a base.
E)none of the above
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Multiple Choice
Q 46Q 46
What would the concentration of OH- be if the concentration of H3O+ was 1 × 10-5M? [H3O+] × [OH-] = Kw = 1 × 10-14
A)1 × 10-14
B)1 × 10-5
C)1 × 109
D)1 × 105
E)1 × 10-9
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Multiple Choice
Q 47Q 47
What would the concentration of OH- be if the concentration of H3O+ was 1 × 10-8M? [H3O+] × [OH-] = Kw = 1 × 10-14
A)1 × 10-14
B)1 × 10-6
C)1 × 108
D)1 × 106
E)1 × 10-8
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Multiple Choice
Q 48Q 48
What would the concentration of H3O+ be if the concentration of OH- was 1 × 10-11M? [H3O+] × [OH-] = Kw = 1 × 10-14
A)1 × 10-3
B)1 × 103
C)1 × 1014
D)1 × 1012
E)1 × 10-6
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Multiple Choice
Q 49Q 49
What would the concentration of H3O+ be if the concentration of OH- was 1 × 10-1M? [H3O+] × [OH-] = Kw = 1 × 10-14
A)1 × 10-3
B)1 × 10-2
C)1 × 10-4
D)1 × 1013
E)none of the above
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Multiple Choice
Q 50Q 50
Qualitatively,what happens to the hydronium ion concentration if you increase the hydroxide ion concentration?
A)The concentration of H3O+ stays the same but the ratio changes.
B)The concentration of H3O+ increases but the ratio stays the same.
C)The concentration of H3O+ increases to neutralize the excess hydroxide.
D)none of the above
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Multiple Choice
Q 51Q 51
Qualitatively,what happens to the hydroxide ion concentration if you decrease the hydronium ion concentration?
A)The concentration of OH- stays the same but the ratio OH-/H3O+ changes.
B)The concentration of OH- increases but the ratio stays the same.
C)The concentration of OH- increases.
D)none of the above
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Multiple Choice
Q 52Q 52
Which of the following statements describes an acidic solution?
A)[H3O+] > [OH-]
B)[H3O+] < [OH-]
C)[H3O+] × [OH-] ≠ 1 × 10-14
D)[H3O+]/[OH-] = 1 × 10-14
E)[H3O+]/[OH-] = 1
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Multiple Choice
Q 53Q 53
Which of the following statements describes a basic solution?
A)[H3O+] > [OH-]
B)[H3O+] < [OH-]
C)[H3O+] × [OH-] ≠ 1 × 10-14
D)[H3O+]/[OH-] = 1 × 10-14
E)[H3O+]/[OH-] = 1
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Multiple Choice
Q 54Q 54
Which of the following statements describes a neutral solution?
A)[H3O+] > [OH-]
B)[H3O+] < [OH-]
C)[H3O+] × [OH-] ≠ 1 × 10-14
D)[H3O+]/[OH-] = 1 × 10-14
E)[H3O+]/[OH-] = 1
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Multiple Choice
Q 55Q 55
-Which of the above illustrations shows a basic aqueous solution?
A)A
B)B
C)C
D)All of the above are neutral solutions.
E)none of the above
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Multiple Choice
Q 56Q 56
-Which of the above illustrations shows an acidic aqueous solution?
A)A
B)B
C)C
D)All of the above are neutral solutions.
E)none of the above
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Multiple Choice
Q 57Q 57
-Which of the above illustrations shows a neutral aqueous solution?
A)A
B)B
C)C
D)All of the above are neutral solutions.
E)none of the above
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Multiple Choice
Q 58Q 58
As the hydronium ion concentration increases,the pH
A)goes down.
B)gets larger.
C)starts to affect the OH- concentration.
D)starts to alter the chemical properties of the water molecules.
E)stays constant.
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Multiple Choice
Q 59Q 59
If the pH of a solution is 10,what is the hydronium ion concentration?
A)1 × 10-10 M
B)1 × 1010 M
C)10 M
D)-10 M
E)- 1 × 1010 M
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Multiple Choice
Q 60Q 60
Which of the following solutions is the most acidic?
A)a solution with a pH = 14
B)a solution with a pH = 10
C)a solution with a pH = 7
D)a solution with a pH = 4
E)All of the solutions are basic.
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Multiple Choice
Q 61Q 61
Which of the following solutions is the most acidic?
A)a solution with a pH = 14
B)a solution with a pH = 12
C)a solution with a pH = 7
D)a solution with a pH = 13
E)All of the solutions are basic.
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Multiple Choice
Q 62Q 62
As the pH increases,the hydroxide ion concentration
A)goes down.
B)gets larger.
C)starts to affect the H+ concentration.
D)starts to decrease because it is reacting with the excess hydronium ions.
E)stays constant.
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Multiple Choice
Q 63Q 63
If the pH of a solution is 10,what is the hydroxide ion concentration?
A)1 × 10-4 M
B)4 M
C)14 M
D)-14 M
E)-1 × 1014 M
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Multiple Choice
Q 64Q 64
If the pH of a solution was 7 and you were to increase the hydronium ion concentration 1000x,what would the pH be?
A)4
B)4 M
C)1 × 10-4 M
D)7000 M
E)10
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Multiple Choice
Q 65Q 65
If the pH of a solution was 7 and you were to increase the hydroxide ion concentration 100x,what would the pH be?
A)9
B)5 M
C)1 × 10-5 M
D)700 M
E)5
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Multiple Choice
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Multiple Choice
Q 69Q 69
What does the value of say about the extent to which water molecule react with themselves?
A)Because the value of is so small,the extent to which water ionizes is quite large.
B)Because the value of is so small,the extent to which water ionizes is quite small.
C)Water molecules react with themselves at a constant rate,never increasing or decreasing.
D)When an acid is added to water,the value of
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Multiple Choice
Q 70Q 70
Why do we use the pH scale to indicate the acidity of a solution rather than simply stating the concentration of hydronium ions?
A)It includes the concentration of hydronium and hydroxide ions.
B)It is used because the general public understands it.
C)It is more accurate to use the pH scale.
D)It is more convenient,since the concentration of hydronium ions is so small.
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Multiple Choice
Q 71Q 71
The amphoteric reaction between two water molecules is endothermic,which means that this reaction requires the input of energy in order to proceed: Energy + O + O → + O The warmer the temperature of the water,the more thermal energy is available for this reaction,and the more hydronium and hydroxide ions are formed.Based on this information,should the value of be expected to increase,decrease,or stay the same with increasing temperature?
A)The value of will stay the same,since it is a constant.
B)The value of will decrease,since there are more hydronium ions than hydroxide ions.
C)The value of will increase since the rise in temperature allows for a higher concentration of both ions.
D)The value of
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Multiple Choice
Q 72Q 72
Along with the pH scale,there is the pOH scale,which indicates the level of "basicity" in a solution.Accordingly,pOH = -log[OH-].What is the sum of the pH and the pOH of a solution always equal to?
A)the negative of the product of the hydronium and hydroxide ions
B)the negative log of ,which is 14
C)The sum would equal 7,since that would be neutral for pH and pOH.
D)It is not constant because it depends on the acid/base solution in question.
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Multiple Choice
Q 73Q 73
When the hydronium ion concentration equals 1 mole per liter,what is the pH of the solution? Is the solution acidic or basic?
A)pH = 0,this is an acidic solution.
B)pH = 1,this is an acidic solution.
C)pH = 10,this is a basic solution.
D)pH = 7,this is a neutral solution.
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Multiple Choice
Q 74Q 74
When the hydronium ion concentration equals 10 moles per liter,what is the pH of the solution? Is the solution acidic or basic?
A)pH = 0,this is an acidic solution.
B)pH = 1,this is an acidic solution.
C)pH = -1,this is an acidic solution.
D)pH = 7,this is a neutral solution.
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Multiple Choice
Q 75Q 75
What would be the concentration of hydronium ions in a solution that had a pH = -3? Why would such a solution be impossible to prepare?
A)Concentration of = 3 M.It is impossible because it is hard to measure such a small amount of hydronium ions accurately.
B)Concentration of = 30 M.It is impossible because pH can not be negative.
C)Concentration of = M.It is impossible because any container used to hold the acid would immediately corrode.
D)Concentration of =
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Multiple Choice
Q 76Q 76
What happens to the pH of an acidic solution as water is added?
A)The pH is not influenced by the addition of water.
B)The pH will decrease as the solution becomes more dilute.
C)The pH will increase as the solution becomes more dilute.
D)The pH will decrease since more hydronium ions are produced from the water.
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Multiple Choice
Q 77Q 77
What is the hydroxide ion concentration in an aqueous solution when the hydronium ion concentration equals 1 × moles per liter?
A)The concentration of hydroxide ions is 1 × moles per liter.
B)The concentration of hydroxide ions is 1 × moles per liter.
C)The concentration of hydroxide ions is 1 × moles per liter.
D)The concentration of hydroxide ions is 1 ×
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Multiple Choice
Q 78Q 78
When a hydronium ion concentration equals 1 × moles per liter,what is the pH of the solution? Is the solution acidic or basic?
A)The pH of this solution is 4,which is acidic.
B)The pH of this solution is 8,which is basic.
C)The pH of this solution is 6,which is acidic.
D)The pH of this solution is 10,which is basic.
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Multiple Choice
Q 79Q 79
When a hydronium ion concentration equals 1 × moles per liter,what is the pH of the solution? Is the solution acidic or basic?
A)The pH is of this solution is 4 and it is acidic.
B)The pH is of this solution is 8 and it is basic.
C)The pH is of this solution is 6 and it is acidic.
D)The pH is of this solution is 10 and it is basic.
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Multiple Choice
Q 80Q 80
What is the hydroxide ion concentration in an aqueous solution where the pH = 5?
A)The hydronium ion concentration equals 1 × .
B)The hydronium ion concentration equals 1 × .
C)The hydronium ion concentration equals 1 × .
D)The hydronium ion concentration equals 1 ×
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Multiple Choice
Q 81Q 81
What happens to the pH of soda water as it loses its carbonation?
A)It does not change since the carbonation has nothing to do with pH.
B)It decreases as it loses the carbon dioxide molecules which form the carbonic acid in the soda.
C)It increases as it loses the carbon dioxide molecules which form the carbonic acid in the soda.
D)It decreases as the soda becomes more concentrated through the loss of the carbon dioxide gases.
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Multiple Choice
Q 82Q 82
Pour vinegar onto beach sand from the Caribbean and the result is a lot of froth and bubbles.Pour vinegar onto beach sand from California,however,and nothing happens.Why?
A)Beaches in tropical climates generally have remnants of volcanic deposit not present in California sand.These deposits contain soil with organic residue.Vinegar's acetic acid reacts with organic matter.
B)The pH of the warm sands of tropical waters is well into the basic range,unlike the beach sand in California.Therefore,the acidic vinegar reacts with Caribbean beach sand but not with sand from California.
C)Beach sand from the Caribbean and many other tropical climates is made primarily of the calcium carbonate remains of coral and shelled creatures.Vinegar is an acid and the calcium carbonate is a base.
D)Caribbean beach sand contains deposits from the mouth of the Mississippi river which carries with it a great deal of contamination from urban waste.These warm water contaminates react with the acid in vinegar.
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Multiple Choice
Q 83Q 83
What would be the best explanation for the fact that most natural water has a pH of about 5.6?
A)Carbon dioxide reacts with water to form an acid.
B)Air contains acid rain particles.
C)Minerals that are dissolved in water are often acidic.
D)Many salts that dissolve in natural waters make the water basic.
E)none of the above
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Multiple Choice
Q 84Q 84
What is the source of acid rain?
A)Acid rain is from dissolved carbon dioxide.
B)All rain is acid rain because rain has a pH is less than 7.
C)Rain is normally basic,but depending on the weather it can get slightly acidic.
D)All rain is acid rain because rain has a hydronium ion concentration greater than 10-7 M.
E)none of the above
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Multiple Choice
Q 85Q 85
Why might an area with a large amount of limestone (CaCO3)be less susceptible to acid rain?
A)The acid in the rain is neutralized by the natural base in the limestone.
B)The rain travels quickly through the porous limestone and therefore the rate of reaction is slower.
C)Limestone is degraded by acid rain and therefore acid rain has the same damaging effects.
D)Only acid rain made from sulfur compounds reacts with the limestone.
E)none of the above
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Multiple Choice
Q 86Q 86
Why is carbon dioxide able to be stored more effectively in ocean water vs.fresh water?
A)The pH of the ocean is pretty high and so the carbon dioxide is trapped in a neutralization reaction.
B)The oceans are large and so you can dissolve more CO2 in them.
C)Gases are more soluble in cold water than warm water and the oceans are colder than fresh water lakes so you can dissolve more CO2 in them.
D)The pH of the ocean is very low and so the carbon dioxide is trapped as an acid because like dissolves like.
E)none of the above
Free
Multiple Choice
Q 87Q 87
Why might a small piece of chalk made of calcium carbonate be useful for alleviating acid indigestion?
A)Calcium carbonate is a base that reacts to neutralize any excess acids.
B)Calcium carbonate is able to absorb excess acid and carry it out of the system.
C)Calcium carbonate is able to add an extra lining to the stomach to protect it from the excess acid.
D)Calcium carbonate is able to turn the acid into a gas which can relieve the build up of excess acid.
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Multiple Choice
Q 88Q 88
How might you tell whether or not your toothpaste contained either calcium carbonate,CaC ,or baking soda,NaHC ,without looking at the ingredients label?
A)if the toothpaste bubbles when heated
B)if the toothpaste bubbles when added to ammonia,such as window cleaner
C)if the toothpaste produces a salt (NaCl)when added to HCl
D)if the toothpaste bubbles when added to vinegar
Free
Multiple Choice
Q 89Q 89
Lakes lying in granite basins,such as those in the northeastern U.S.,tend to become acidified by acid rain more readily than lakes lying in limestone basins,such as those found in the midwestern U.S.Why is this so?
A)The granite contains acidic minerals that dissolve in the rain water and are added to the lakes.
B)Since the acidified water cannot percolate through the granite,the acid in the lakes becomes more concentrated.
C)The limestone,which is calcium carbonate,serves to neutralize the acid in the rain.
D)There is more acid rain in the northeast than in the midwestern regions of the U.S.
Free
Multiple Choice
Q 90Q 90
Cutting back on the pollutants that cause acid rain is one solution to the problem of acidified lakes.Suggest another.
A)stop using NaCl to salt the roads in the winter
B)add a neutralizing substance such as limestone
C)add ammonium ions to the lakes
D)add chlorine and filter the water to remove any acidity in the lake
Free
Multiple Choice
Q 91Q 91
What is oxidation?
A)the loss of electrons
B)the reaction with oxygen
C)the reduction of oxygen
D)the gaining of electrons
E)the addition of an electron to the valence shell
Free
Multiple Choice
Q 92Q 92
What is a reduction?
A)the gain of electrons
B)the reduction of the number of electrons
C)the loss of an electron from the valence shell
D)the reaction of oxygen with a reductant
E)the formation of red compounds in the presence of an oxidant
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Multiple Choice
Q 93Q 93
Which of the following statements is untrue about oxidation and reduction processes?
A)An oxidation can happen without a reduction.
B)It involves the exchange of electrons.
C)Often ions are generated or consumed.
D)Electrons are often involved in oxidation and reduction reactions.
E)All of the above are true.
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Multiple Choice
Q 94Q 94
Which of the following statements about oxidation and reduction reactions is true?
A)More than one electron can be transferred in an oxidation and reduction reaction.
B)In a half-reaction,only half of an electron is transferred.
C)Only neutral atoms are formed in oxidation and reduction reactions.
D)A half-reaction is only used for reduction reactions.
E)None of the above are true.
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Multiple Choice
Q 95Q 95
How many electrons are gained or lost in the following half-reaction? Na → Na+
A)1 electron is lost
B)1/2 electron is gained
C)1/2 electron is lost
D)1 electron is gained
E)2 electrons are gained
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Multiple Choice
Q 96Q 96
How many electrons are gained or lost in the following half-reaction? 2 Na → 2 Na+
A)2 electrons are lost
B)1/2 electron is gained
C)1/2 electron is lost
D)2 electrons are gained
E)4 electrons are gained
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Multiple Choice
Q 97Q 97
How many electrons are gained or lost in the following half-reaction? Cl2 → 2 Cl-
A)2 electrons are lost
B)1/2 electron is gained
C)1/2 electron is lost
D)2 electrons are gained
E)4 electrons are gained
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Multiple Choice
Q 98Q 98
How many electrons are gained or lost in the following half-reaction? Zn → Zn+2
A)2 electrons are lost
B)1/2 electron is gained
C)1/2 electron is lost
D)2 electrons are gained
E)4 electrons are gained
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Multiple Choice
Q 99Q 99
Which of the half-reactions below would be complementary,balance the following half-reaction,and be chemically reasonable? Br2 → 2 Br-
A)2 K → 2 K+
B)K+ → K
C)K → K+
D)2 K+ → 2 K
E)K → K+2
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Multiple Choice
Q 100Q 100
Which of the half-reactions below would be complementary and balance the following half-reaction? Zn+2 → Zn
A)Cu → Cu+2
B)K+ → K
C)2 Cu → 2 Cu+2
D)2 K+ → 2 K
E)Cl2 → 2 Cl-
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Multiple Choice
Q 101Q 101
Which of the following species is undergoing oxidation? 2 CuBr → 2Cu + Br2
A)Cu
B)CuBr
C)Cu+
D)Br-
E)Br2
Free
Multiple Choice
Q 102Q 102
Which of the following species is undergoing reduction? 2 CuBr → 2Cu + Br2
A)Cu
B)CuBr
C)Cu+
D)Br-
E)Br2
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Multiple Choice
Q 103Q 103
Which of the following species is the oxidizing agent? 2 CuBr → 2Cu + Br2
A)Cu
B)CuBr
C)Cu+
D)Br-
E)Br2
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Multiple Choice
Q 104Q 104
Which of the following species is the reducing agent? 2 CuBr → 2Cu + Br2
A)Cu
B)CuBr
C)Cu+
D)Br-
E)Br2
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Multiple Choice
Q 105Q 105
Which of the following materials is most likely to undergo oxidation?
A)Na
B)Na+
C)Cl2
D)Cl-
E)both A and B
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Multiple Choice
Q 106Q 106
Which of the following materials is most likely to act as an oxidizing agent?
A)Na
B)Na+
C)Cl2
D)Cl-
E)both A and B
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Multiple Choice
Q 107Q 107
Which of the following materials is most likely to undergo reduction?
A)Na
B)Na+
C)Cl2
D)Cl-
E)both A and B
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Multiple Choice
Q 108Q 108
Which of the following materials is most likely to act as a reducing agent?
A)Na
B)Na+
C)Cl2
D)Cl-
E)both A and B
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Multiple Choice
Q 109Q 109
What might the relationship be between an element's electronegativity and its ability to behave as an oxidizing agent?
A)As the electronegativity goes up the ability of an element to act as an oxidant increases.
B)As the electronegativity goes up the ability of an element to act as an oxidant decreases.
C)As the electronegativity goes up the ability of an element to act as an oxidant stays the same.
D)As the electronegativity increases the element has a tendency to undergo oxidation.
E)none of the above
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Multiple Choice
Q 110Q 110
What element is oxidized in the following equation and what element is reduced? + 2 Ag → Sn + 2 Ag⁺
A)The tin ion, ,is oxidized,while the silver,Ag,is reduced.
B)The tin ion, ,is reduced,while the silver,Ag,is oxidized.
C)Both the tin ion, ,and the silver,Ag,are reduced.
D)Both the tin ion,
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Multiple Choice
Q 111Q 111
What element is behaves as the oxidizing agent in the following equation and what element behaves as the reducing agent? + 2 Ag → Sn + 2 Ag⁺
A)The tin ion, ,is the oxidizing agent while silver,Ag,is the reducing agent.
B)The tin ion,Sn2+,is the reducing agent while silver,Ag,is the oxidizing agent.
C)The tin,Sn,is the reducing agent while silver ion,Ag⁺,is the oxidizing agent.
D)The tin,Sn,is the oxidizing agent while silver ion,Ag⁺,is the reducing agent.
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Multiple Choice
Q 112Q 112
Hydrogen sulfide,H2S,burns in the presence of oxygen, ,to produce water, O,and sulfur dioxide,SO2.Through this reaction,is sulfur oxidized or reduced? 2 S + 3 → 2 O + 2
A)Sulfur is reduced.
B)Sulfur is oxidized.
C)Sulfur is both oxidized and reduced.
D)Sulfur is neither oxidized nor reduced.
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Multiple Choice
Q 113Q 113
For each of the following unbalanced equations,which is depicted: oxidation or reduction? a)Cr → b) Sn →
A)a)oxidation; b)reduction
B)a)reduction; b)oxidation
C)a)reduction; b)reduction
D)a)oxidation; b)oxidation
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Multiple Choice
Q 114Q 114
-In the above diagram,which atom is oxidized,the darker colored atom or the lighter colored atom?
A)Both of the atoms are oxidized.
B)Neither of the atoms is oxidized.
C)Only the darker colored atom is oxidized.
D)Only the lighter colored atom is oxidized.
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Multiple Choice
Q 115Q 115
-In the above diagram,which atom behaves as the oxidizing agent,the lighter colored atom or the darker colored atom?
A)Both atoms behave as the oxidizing agent.
B)Neither of the atoms behave as the oxidizing agent.
C)The darker colored atom behaves as the oxidizing agent.
D)The lighter colored atom behaves as the oxidizing agent.
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Multiple Choice
Q 116Q 116
How does an atom's electronegativity relate to its ability to become oxidized?
A)The greater the electronegativity of an atom,the greater its ability to become oxidized.
B)The lower the electronegativity of an atom,the lower its ability to become oxidized.
C)The greater the electronegativity of an atom,the lower its ability to become oxidized.
D)Electronegativity does not effect the atom's ability to become oxidized.
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Multiple Choice
Q 117Q 117
The general chemical equation for photosynthesis is shown below.Through this reaction is the carbon oxidized or reduced? How can you tell? 6 + 6 O → + 6
A)Oxidized,since carbon is in the +4 oxidation state in but in the +6 oxidation state in the product, ,glucose.
B)Reduced,since in carbon dioxide there are two oxygen atoms for every one carbon but within the product, ,(glucose),there is only one oxygen for every one carbon.
C)Neither,since carbon does not change its oxidation state and is neither oxidized nor reduced.
D)Both,since the carbon atoms within the glucose molecules display two different charge states.
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Multiple Choice
Q 118Q 118
The general chemical equation for photosynthesis is shown below.Through this reaction are the oxygens of the water molecules,H2O,oxidized or reduced? 6 + 6 O → + 6
A)The oxygens of the water molecules are oxidized.
B)The oxygens of the water molecules are reduced.
C)The oxygens of some of these water molecules are oxidized while others are reduced.
D)The oxygens of the water molecules are neither oxidized nor reduced.
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Multiple Choice
Q 119Q 119
Chemical equations need to be balanced not only in terms of the number of atoms,but also by the charge.In other words,just as there should be the same number of atoms before and after the arrow of an equation,there should be the same charge.What set of coefficients is necessary to balance the following chemical equation? ________ + ________ Ag → ________ Sn + ________ Ag⁺
A)1,2,1,2
B)1,1,1,2
C)1,2,2,2
D)1,1,2,1
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Multiple Choice
Q 120Q 120
Chemical equations need to be balanced not only in terms of the number of atoms,but also by the charge.In other words,just as there should be the same number of atoms before and after the arrow of an equation,there should be the same charge.What set of coefficients is necessary to balance the following chemical equation? ________ + ________ Cl⁻ → ________ + ________
A)1,2,1,1
B)2,2,2,1
C)1,4,1,2
D)3,4,3,2
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Multiple Choice
Q 121Q 121
Which element is closer to the upper right corner of the periodic table,the one indicated by the lighter colored atoms or the darker colored atoms?
A)the element indicated by the darker color
B)the element indicated by the lighter color
C)More information is needed in order to determine which element is closer to the upper right of the periodic table.
D)Both the lighter and darker colored elements are likely found at the upper right corner of the periodic table.
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Multiple Choice
Q 122Q 122
Clorox is a laundry bleaching agent used to remove stains from white clothes.Suggest why the name begins with Clor- and ends with -ox.
A)Clor~ because it has chlorine,~ox because it is as strong as an ox.
B)The active ingredient contains chlorine atoms,which behave as strong oxidizing agents.
C)Chlor~ because it has chlorine ions,~ox because it is reduced.
D)Chlor~ because it has chlorine ions,~ox because it uses oxygen.
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Multiple Choice
Q 123Q 123
When lightning strikes,nitrogen molecules, ,and oxygen molecules, ,in the air react to form nitrates, ⁻,which come down in the rain to help fertilize the soil.Is this this an example of oxidation or reduction?
A)The formation of nitrates is an example of oxidation.
B)The formation of nitrates is an example of reduction.
C)Both.The nitrogen is oxidized as it reacts with the oxygen while the oxygen is reduced.
D)Neither.Although the bonds of both the and molecules are broken to form the
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Multiple Choice
Q 124Q 124
Glucose, ,is a simple sugar that the body metabolizes into two molecules of pyruvic acid, .Is the glucose oxidized or reduced as it transforms into pyruvic acid?
A)The glucose is oxidized.
B)The glucose is reduced.
C)Parts of the glucose molecule are oxidized while others are reduced.
D)Glucose is neither oxidized or reduced as it transforms into pyruvic acid.
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Multiple Choice
Q 125Q 125
Upon ingestion,grain alcohol, O,is metabolized into acetaldehyde, O,which is a toxic substance causing headaches as well as joint pains typical of a "hangover." Is the grain alcohol oxidized or reduced as it transforms into acetaldehyde?
A)The grain alcohol is reduced.
B)The grain alcohol is oxidized.
C)Some of the grain alcohol is oxidized and some is reduced to other products.
D)The grain alcohol is neither oxidized nor reduced.
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Multiple Choice
Q 126Q 126
Which of the following statements about electrochemistry is not true?
A)It is the study of how electrical energy and chemical reactions are related.
B)It involves the use of a set of oxidation-reduction reactions to produce electrical current.
C)It involves the use of electrical current to produce an oxidation-reduction reaction.
D)It is the study of how electrons are transferred from one chemical compound to another.
E)All of the above are true.
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Multiple Choice
Q 127Q 127
The following set of redox reactions takes place when iron is dipped in a solution of copper ions. Fe → Fe+2 + 2e-
Cu+2 + 2e- → Cu
Which of the following describes what is happening on the surface of the iron?
A)The copper starts to plate out on iron.
B)The iron rusts in the water.
C)The iron starts to plate out on the copper.
D)The iron corrodes the copper.
E)none of the above
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Multiple Choice
Q 128Q 128
The following set of redox reactions takes place when iron is dipped into a solution of copper ions. Fe → Fe+2 + 2e-
Cu+2 + 2e- → Cu
Which of the following describes what is happening with the electrons in the solution?
A)The iron metal is releasing electrons and they are traveling to the copper ions.
B)The copper is releasing electrons and they are traveling to the iron ions.
C)The iron ions are gaining electrons from the copper metal.
D)The copper ions are releasing electrons and they are traveling to the iron metal.
E)none of the above
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Multiple Choice
Q 129Q 129
What is the purpose of a salt-bridge?
A)to allow ions to migrate between solutions
B)to allow people to cross over salt water
C)to allow electrons to migrate through solutions
D)to allow salt to form in the oxidation-reduction reactions
E)none of the above
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Multiple Choice
Q 130Q 130
Which of the following describes an electrode?
A)Any material that conducts electrons into a media where electrochemical reactions are taking place.
B)Any material that conducts electrons out of a media where electrochemical reactions are taking place.
C)Any material that conducts electrons.
D)Any material that is undergoing an oxidation-reduction reaction in a battery.
E)either A or B
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Multiple Choice
Q 131Q 131
Which of the following statements best describes a cathode?
A)the negatively charged electrode of a battery or electrochemical apparatus
B)the place where oxidation is taking place in a battery or electrochemical apparatus
C)the place from which electrons are flowing away from
D)all of the above
E)none of the above
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Multiple Choice
Q 132Q 132
Which of the following statements best describes an anode?
A)the negatively charged electrode of a battery or electrochemical apparatus
B)the place where oxidation is taking place in a battery or electrochemical apparatus
C)the place from which electrons are flowing away from
D)all of the above
E)none of the above
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Multiple Choice
Q 133Q 133
What is the purpose of the salt bridge in a voltaic cell?
A)to prevent any further migration of electrons through the wire
B)to allow for the build up of positively charged ions in one container and negatively charged ions in the other container
C)to allow the and the to flow freely between the two containers
D)to allow for a balance of charge between the two chambers
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Multiple Choice
Q 134Q 134
In the oxidation-reduction reaction Mg(s)+ (aq)→ 3 (aq)+ Cu(s),which atom or ion is reduced? Which atom or ion is oxidized?
A)The ion is oxidized as it gains electrons from the copper metal,Cu.The magnesium metal,Mg,is reduced as it loses electrons to form .
B)The ion is reduced as it gains electrons from the copper metal,Cu.The is oxidized as it loses electrons to the .
C)The ion is reduced as it gains electrons to form copper metal,Cu.The magnesium metal,Mg,is oxidized as it loses electrons to form .
D)Since Mg goes from a solid to an aqueous solution and Cu goes from an aqueous solution to a solid,an oxidation-reduction reaction did not occur.
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Multiple Choice
Q 135Q 135
In a battery,the following two oxidation-reduction reactions are taking place: rxn A: Zn → Zn+2 + 2e-
Rxn B: 2 NH4+ + 2e- → 2 NH3 + H2
Which reaction is taking place at the anode?
A)rxn A
B)rxn B
C)Both reactions are happening at both the anode and cathode.
D)Both reactions are happening at the electrode.
E)The reaction takes place at the electrode,not the anode.
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Multiple Choice
Q 136Q 136
In a battery,the following two oxidation-reduction reactions are taking place: rxn A: Zn → Zn+2 + 2e-
Rxn B: 2 NH4+ + 2e- → 2 NH3 + H2
Which reaction is taking place at the cathode?
A)rxn A
B)rxn B
C)Both reactions are happening at both the anode and cathode.
D)Both reactions are happening are happening at the electrode.
E)The reaction takes place at the electrode,not the cathode.
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Multiple Choice
Q 137Q 137
In a battery,the following two oxidation-reduction reactions are taking place: rxn A: Zn + 2 OH- → ZnO + H2O + 2e-
Rxn B: 2 MnO2 + H2O + 2e- → Mn2O3 + 2 OH-
What is undergoing oxidation?
A)Zn
B)ZnO
C)MnO2
D)H2O
E)OH-
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Multiple Choice
Q 138Q 138
In a battery,the following two oxidation-reduction reactions are taking place: rxn A: Zn + 2 OH- → ZnO + H2O + 2e-
Rxn B: 2 MnO2 + H2O + 2e- → Mn2O3 + 2 OH-
What is undergoing reduction?
A)Zn
B)ZnO
C)MnO2
D)H2O
E)OH-
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Multiple Choice
Q 139Q 139
In a battery,the following oxidation-reduction reaction is taking place: Mn2O3 + ZnO → 2 MnO2 + Zn
What is undergoing reduction as written?
A)Zn
B)ZnO
C)MnO2
D)Mn2O3
E)none of the above
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Multiple Choice
Q 140Q 140
In a battery,the following oxidation-reduction reactions are taking place: Mn2O3 + ZnO → 2 MnO2 + Zn
What is undergoing an oxidation as written?
A)Zn
B)ZnO
C)MnO2
D)Mn2O3
E)none of the above
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Multiple Choice
Q 141Q 141
In a battery,the following oxidation-reduction reactions are taking place: Mn2O3 + ZnO → 2 MnO2 + Zn
What is being formed at the cathode?
A)Zn
B)ZnO
C)MnO2
D)Mn2O3
E)none of the above
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Multiple Choice
Q 142Q 142
In a battery,the following oxidation-reduction reactions are taking place: Mn2O3 + ZnO → 2 MnO2 + Zn
What is being formed at the anode?
A)Zn
B)ZnO
C)MnO2
D)Mn2O3
E)none of the above
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Multiple Choice
Q 143Q 143
In a battery,if the following oxidation-reduction reactions takes place normally: Mn2O3 + ZnO → 2 MnO2 + Zn
What reaction would be taking place if you were charging the battery?
A)2 MnO2 + Zn → Mn2O3 + ZnO
B)ZnO → Zn
C)Mn2O3 → MnO2
D)all of the above
E)none of the above
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Multiple Choice
Q 144Q 144
Why might disposing of a lead-acid battery,nickel-cadmium battery or mercury battery in a landfill be a bad thing?
A)Cadmium,mercury,and lead are all toxic metals and could leak out of the landfill.
B)Cadmium,mercury,and lead are all very reactive and generate highly unstable compounds.
C)Cadmium,mercury,and lead are all radioactive and release radiation.
D)all of the above
E)none of the above
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Multiple Choice
Q 145Q 145
Your car lights were left on while you were shopping,and now your car battery is dead.Has the pH of the battery fluid increased or decreased?
A)The pH of the battery fluid has increased.
B)The pH of the battery fluid has decreased.
C)The pH of the battery fluid does not change.
D)Since the lights were left on and the battery is dead,the pH of the battery fluid must be zero.
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Multiple Choice
Q 146Q 146
Why does a battery that has thick zinc walls last longer than one that has thin zinc walls?
A)Thick zinc walls prevent the battery from over heating.
B)Thicker zinc walls prevent electrons from being lost into the surrounding environment.
C)Thicker zinc walls last longer at holding in the battery acid.
D)The zinc walls are transformed into zinc ions as the battery provides electricity.
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Multiple Choice
Q 147Q 147
What is the primary difference between a fuel cell and a battery?
A)Fuel cells do not run down because they can be refueled; batteries run down and need to be recharged.
B)Batteries can be recharged,fuel cells cannot.
C)Batteries supply electricity; fuel cells supply heat.
D)Fuel cells oxidize to supply electricity,batteries reduce to supply electricity.
E)Fuel cells do not use metals as oxidants and reductants,batteries have a static reservoir of oxidant and reductant.
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Multiple Choice
Q 148Q 148
In one type of fuel cell the following oxidation-reduction reactions are taking place: 2 H2 + O2 → 2 H2O
What is the fuel?
A)H2
B)O2
C)H2O
D)all of the above
E)none of the above
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Multiple Choice
Q 149Q 149
In one type of fuel cell,the following oxidation-reduction reactions are taking place: 2 H2 + O2 → 2 H2O
What is the oxidant?
A)H2
B)O2
C)H2O
D)all of the above
E)none of the above
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Multiple Choice
Q 150Q 150
What is one of the advantages of a fuel cell?
A)They can run for a very long time as long as you keep adding fuel.
B)They are more efficient than combustion.
C)They have lower emission of pollutants than combustion.
D)all of the above
E)only A and B
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Multiple Choice
Q 151Q 151
What is one of the drawbacks to using fuel cells?
A)The fuel of the fuel cells is hard to handle.
B)They are less efficient than combustion energy sources or batteries.
C)They are very big and bulky,which makes them hard to use in small devices.
D)There are no drawbacks.
E)only A and B
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Multiple Choice
Q 152Q 152
Why don't the electrodes of a fuel cell deteriorate the way the electrodes of a battery do?
A)As long as fuel is supplied,fuel cells don't run down,but car batteries die when the electron-producing chemicals are consumed.
B)Fuel cell electrodes are made of graphite,which does not deteriorate.
C)Fuel cell electrodes are self-replenishing thanks to the KOH-containing paste.
D)Fuel cell do not use electrodes,so there are none to deteriorate.
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Multiple Choice
Q 153Q 153
How is electrolysis different from what is going on chemically inside a battery?
A)They are the same process,just reversed.
B)Electrolysis does not use electrons.
C)Electrolysis only uses electrons from a cathode.
D)You cannot make pure compounds with electrolysis.
E)You do not produce a chemical change in electrolysis.
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Multiple Choice
Q 154Q 154
For the following electrolysis reaction: 2 AlOF3-2 + C → 2 Al + CO2 + F-
Where would the aluminum form?
A)cathode
B)anode
C)in solution
D)Aluminum formation does not happen because electrons do not flow in above reaction.
E)none of the above
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Multiple Choice
Q 155Q 155
Why is recycling of aluminum better for the environment than electrolysis of bauxite (an aluminum ore)?
A)It takes less energy to recycle aluminum.
B)Electrolysis releases harmful gases into the atmosphere.
C)The bauxite is extremely rare and there is very little aluminum in the world.
D)Electricity is extremely cheap and it is better to use cheap electricity.
E)none of the above
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Multiple Choice
Q 156Q 156
A major source of chlorine gas, ,is from the electrolysis of brine,which is concentrated salt water, Which of the following is the balanced chemical reaction for this electrolysis reaction?
A)NaCl (aq)+ H2O → NaOH (aq)+ (g)+ (g)
B)2 NaCl (aq)+ O → O (aq)+ 2 HCl (aq)
C)2 NaCl (aq)+ 2 O → 2 Na (s)+ O2 (g)+ 2 (g)+ (g)
D)2 NaCl (aq)+ O → 2 NaH (aq)+
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Multiple Choice
Q 157Q 157
A major source of chlorine gas, ,is from the electrolysis of brine,which is concentrated salt water, What is the sign of the electrode where the chlorine gas is formed? Is it negative or positive?
A)Positive,since the chloride ions lose electrons to form chlorine molecules.
B)Negative,since the chlorine gas needs to deposit electrons to form chloride ions.
C)Neither,since chlorine gas is a neutral molecule,there is not electrode attraction.
D)Both,since the chloride ions from NaCl (aq)are attracted to the positive electrode to form chlorine molecules while the produced chlorine gas molecules move to deposit electrons at the negative electrode.
Free
Multiple Choice
Q 158Q 158
Sodium metal is
A)oxidized in the production of aluminum.
B)reduced in the production of aluminum.
C)both oxidized and reduced in the production of aluminum.
D)neither oxidized nor reduced in the production of aluminum.
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Multiple Choice
Q 159Q 159
Jewelry is often manufactured by electroplating an expensive metal such as gold over a cheaper metal.A setup for this process can be sketched as follows: What would happen if the battery connections were suddenly reversed?
A)The ring would continue to electroplate with gold.
B)Gold ions in solution would get reduced and settle to the bottom of the container.
C)Gold ions in solution would begin to electroplate onto the gold electrode.
D)All electrolysis would stop.
Free
Multiple Choice
Q 160Q 160
How might electrolysis be used to raise the hull of a sunken ship?
A)An electric current passed through the hull of the ship would produce electrolysis and the gases trapped in the compartments of the vessel would push it upwards.
B)The electrolysis of the water beneath the hull of the ship would boil the water and create upward pressure,thus buoying the ship upward.
C)The gaseous products of the electrolysis of water could be collected with large bags attached to the hull of the ship.As the bags inflate with the gas they are buoyed upward pulling the ship also upward.
D)Electrolysis could only be used to raise the hull of a ship if the ship were made of iron.If so,the electrolysis of the iron metal might produce enough gas to lift the ship.
Free
Multiple Choice
Q 161Q 161
Why is oxygen usually an oxidizing agent?
A)It is a very electronegative element.
B)It does not undergo reduction.
C)It likes to be oxidized.
D)It is very abundant and so it is easier to react than nitrogen.
E)all of the above
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Multiple Choice
Q 162Q 162
Rust has a tendency to form when iron in contact with water reacts according to the following reaction: 4 Fe + 3 O2 → 2 Fe2O3
What is happening at the cathodic region?
A)Iron is being oxidized.
B)Oxygen is being oxidized.
C)Oxygen is being reduced.
D)Iron is being reduced.
E)none of the above
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Multiple Choice
Q 163Q 163
Rust has a tendency to form when iron in contact with water reacts according to the following reaction: 4 Fe + 3 O2 → 2 Fe2O3
What is happening at the anodic region?
A)Iron is being oxidized.
B)Oxygen is being oxidized.
C)Oxygen is being reduced.
D)Iron is being reduced.
E)none of the above
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Multiple Choice
Q 164Q 164
Aluminum metal undergoes the same basic corrosion process that iron does yet it does not decompose as rapidly.Why?
A)The aluminum oxide does not flake off like rust and acts as a protective layer.
B)Aluminum is harder to oxidize than iron.
C)Aluminum is harder to reduce than iron.
D)The aluminum oxide product undergoes a reduction to produce aluminum metal.
E)The aluminum is galvanized,which prevents oxidation.
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Multiple Choice
Q 165Q 165
How does connecting a metal like iron with a wire to a metal that is easier to oxidize like zinc help prevent corrosion of the iron?
A)The other metal is oxidized instead and the electrons travel to the iron,keeping it from oxidizing.
B)The other metal absorbs the electrons from the iron,which keeps the iron from undergoing oxidation.
C)The wire is acting as an oxidant and keeps the two metals from undergoing other chemical reactions.
D)There is no salt-bridge,so there is no reaction between the two metals.
E)The other metal is oxidized and adsorbs all the oxidant,keeping it away from the iron.
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Multiple Choice
Q 166Q 166
How would connecting iron with a wire to a piece of metal like copper,which undergoes reduction very easily,affect the rate at which the iron corrodes?
A)It would increase the rate of corrosion.
B)It would decrease the rate of corrosion.
C)The rate would stay the same.
D)Rates are only affected by temperature.
E)none of the above
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Multiple Choice
Q 167Q 167
Why is the formation of iron hydroxide,Fe ,from and O not considered an oxidation-reduction reaction?
A)The iron is only oxidized and nothing is reduced.
B)The iron is only reduced,not oxidized.
C)The ion is not changed during this chemical reaction.
D)Iron can never be oxidized or reduced.
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Multiple Choice
Q 168Q 168
A chemical equation for the combustion of propane,C3H8,is shown below.Through this reaction is the carbon oxidized or reduced? + 5 → 3 + 4 O
A)The carbon is oxidized.
B)The carbon is reduced.
C)Some of the carbons are oxidized while others are reduced.
D)The carbon is neither oxidized nor reduced.
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Multiple Choice
Q 169Q 169
The oxidation of iron to rust is a problem structural engineers need to be concerned about,but the oxidation of aluminum to aluminum oxide is not so much of a problem.Why?
A)Since aluminum is so light and inexpensive,it is easily replaced when corroded.
B)Aluminum oxide is insoluble in water and thus forms a protective coating that prevents continued oxidation of the aluminum.
C)Aluminum oxide is even stronger than aluminum.
D)The oxidation of aluminum is a very slow reaction,taking hundreds of years before any structural changes are noticed.
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Multiple Choice
Q 170Q 170
How many electrons are transferred from iron atoms to oxygen atoms in the formation of two molecules of iron hydroxide,Fe ?
A)4 electrons
B)8 electrons
C)16 electrons
D)12 electrons
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Multiple Choice
Q 171Q 171
Why are combustion reactions generally exothermic?
A)Hydrogen easily pulls electrons from the oxygen in water molecules and are reduced.
B)During combustion oxygen is oxidized,which gives off lots of energy.
C)Combustion involves the transfer of electrons to oxygen,which has an extremely high tendency for gaining electrons.
D)It is highly exothermic because combustion involves an oxidation-reduction reaction between a metallic material and oxygen.
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Multiple Choice
Q 172Q 172
Water is 88.88 percent oxygen by mass.Oxygen is exactly what a fire needs to grow brighter and stronger.So why doesn't a fire grow brighter and stronger when water is added to it?
A)Oxygen in water is already "reduced" from the hydrogen atoms,so this oxygen atom no longer has a great attraction for additional electrons.
B)The oxygen is chemically bound to hydrogen atoms.
C)Oxygen in water is completely different from oxygen ,which is what is required for combustion.
D)all of the above
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Multiple Choice
Q 173Q 173
Iron atoms have a greater tendency to oxidize than do copper atoms.Is this good news or bad news for a home in which much of the plumbing consists of iron and copper pipes connected together? Explain.
A)This is bad news,since the iron atoms will be reduced by the copper atoms.
B)This is not a problem,since the strength of the copper will make up for the weakness of the iron.
C)It is bad news.The iron atoms will lose electrons to the copper atoms,which will pass those electrons onto oxygen atoms that are in contact with the surface.
D)This is not a problem since any electrons lost will be replaced by copper electrons.
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Multiple Choice
Q 174Q 174
Copper atoms have a greater tendency to be reduced than iron atoms do.Was this good news or bad news for the Statue of Liberty,whose copper exterior was originally held together by steel rivets?
A)This was good news since the steel rivets prevented the copper from eroding.
B)Electrons will preferentially flow from the iron to the copper and then onto oxygen.Corrosion is thus accelerated around the interface of these two metals.
C)This combination of metals have no effect on each other and that is why engineers chose to use them together.
D)This combination of metals caused the copper to oxidize and turn green.
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Multiple Choice
Q 175Q 175
One of the products of combustion is water.Why doesn't this water extinguish the combustion?
A)While areas of combustion are being extinguished,new areas are combusting.
B)Combustion only produces micro amounts of water.
C)The chemical combustion reaction is happening too fast for the water to have an effect on the fire.
D)This water is in the gaseous phase and merely floats away from the fire.
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Multiple Choice
Q 176Q 176
Why is the air over an open flame always moist?
A)The hot flame vaporizes the water in the air above the flame.
B)One of the products of combustion is water vapor.
C)Warm air contains more humidity than cold air.
D)None of the above is true.
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Multiple Choice
Q 177Q 177
Upon combustion,about how many grams of water vapor are produced from every 16 grams of methane, ? + 2 → + 2 O
A)16 grams
B)18 grams
C)36 grams
D)8 grams
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Multiple Choice