Reference no: EM13857278
Question 1
Identify the acid or base behavior of each substance in these reactions:
H3O + Cl- ? H2O + HCl
Question 1 options:
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H3O+ acts as an acid, Cl- acts as a base, H2O acts an acid, HCl acts as a base.
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H3O+ acts as an base, Cl- acts as a acid, H2O acts an acid, HCl acts as a base.
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H3O+ acts as an acid, Cl- acts as a base, H2O acts an base, HCl acts as a acid.
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H3O+ acts as an base, Cl- acts as a acid, H2O acts an base, HCl acts as an acid.
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Question 2
Acetic acid, shown below, has 4 hydrogen atoms-one bonded to an oxygen and three bonded to a carbon. When this molecule behaves as an acid, it donates only the hydrogen bonded to the oxygen. The hydrogens bonded to the carbon remain intact. Why?
Question 2 options:
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The oxygen is much better at accommodating a negative charge than is carbon.
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The hydrogen attached to the oxygen extends farther away from the center of the molecule.
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The carbon is bonded to three hydrogens while the oxygen is bonded to only one hydrogen.
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The oxygen within acetic acid has two lone pairs of electrons that help to destabilize the oxygen-hydrogen bond.
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Question 3
Qualitatively, what happens to the hydroxide ion concentration if you decrease the hydronium ion concentration?
Question 3 options:
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The concentration of hydroxide decreases to neutralize the excess hydronium.
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The concentration of OH- stays the same but the ratio OH-/H3O+ changes.
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The concentration of OH- increases but the ratio stays the same.
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The concentration of OH- increases.
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None of these
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Question 4
Qualitatively, what happens to the hydronium ion concentration if you increase the hydroxide ion concentration?
Question 4 options:
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The concentration of hydroxide decreases to neutralize the excess hydronium.
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The concentration of H3O+ stays the same but the ratio changes.
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The concentration of H3O+ increases but the ratio stays the same.
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The concentration of H3O+ increases to neutralize the excess hydroxide.
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None of these
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Question 5
When a hydronium ion concentration equals 1 × 10-4 moles per liter, what is the pH of the solution? Is the solution acidic or basic?
Question 5 options:
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The pH is of this solution is 4 and it is acidic.
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The pH is of this solution is 8 and it is basic.
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The pH is of this solution is 6 and it is acidic.
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The pH is of this solution is 10 and it is basic.
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Question 6
How does a base like NH3 raise the hydroxide ion concentration?
Question 6 options:
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The NH3 molecule removes a proton from a water molecule.
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The NH3 molecule releases a proton that has to be neutralized by a water molecule.
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The NH3 molecule is not a base and therefore does not change the hydroxide ion concentration.
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The NH3 molecule releases reacts with a hydronium molecule, altering the number of hydroxide ions in the process.
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None of these
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Question 7
Which of the following statements about buffers is untrue?
Question 7 options:
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The pH of a buffer solution cannot change.
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Addition of small amounts of acid to a buffer changes the pH.
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Addition of small amounts of base to a buffer changes the pH.
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A salt from the reaction of a strong acid and a strong base can be used to make a buffer.
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None of these are true.
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Question 8
Carbon dioxide reacts with water to form ________.
Question 8 options:
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carbon dioxide and water
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carbonic acid
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sodium bicarbonate
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hydrated carbon
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Question 9
The overall rate at which humans are producing carbon dioxide is ________.
Question 9 options:
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increasing
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decreasing
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some years increasing and other years decreasing
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remaining about the same
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Question 10
What is a reduction?
Question 10 options:
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the gain of electrons
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the reduction of the number of electrons
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the loss of an electron from the valence shell
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the reaction of oxygen with a reductant
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the formation of red compounds in the presence of an oxidant
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Question 11
The zinc within a copper penny does not oxidize because ________.
Question 11 options:
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zinc is an inert metal
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it is not exposed to oxygen
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of an impossible build up of charge
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of a lack of water
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Question 12
The following set of redox reactions takes place when iron is dipped into a solution of copper ions.
Fe → Fe2+ + 2e-
Cu2+ + 2e- → Cu
Which of the following describes what is happening with the electrons in the solution?
Question 12 options:
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The iron metal is releasing electrons and they are traveling to the copper ions.
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The copper is releasing electrons and they are traveling to the iron ions.
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The iron ions are gaining electrons from the copper metal.
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The copper ions are releasing electrons and they are traveling to the iron metal.
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None of these
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Question 13
Which of the following statements best describes a cathode?
Question 13 options:
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the negatively charged electrode of a battery or electrochemical apparatus
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the place where oxidation is taking place in a battery or electrochemical apparatus
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the place from which electrons are flowing away from
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All of these
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None of these
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Question 14
In a battery, the following two oxidation-reduction reactions are taking place:
rxn A: Zn → Zn2+ + 2e-
rxn B: 2NH4+ + 2e- → 2NH3 + H2
Which reaction is taking place at the cathode?
Question 14 options:
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rxn A
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rxn B
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Both reactions are happening at both the anode and cathode.
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Both reactions are happening are happening at the electrode.
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The reaction takes place at the electrode, not the cathode.
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Question 15 In a battery, the following two oxidation-reduction reactions are taking place:
rxn A: Zn + 2OH- → ZnO + H2O + 2e-
rxn B: 2MnO2 + H2O + 2e- → Mn2O3 + 2OH-
What is undergoing reduction?
Question 15 options:
Question 16
In one type of fuel cell the following oxidation-reduction reactions are taking place:
2 H2 + O2 → 2 H2O
What is the fuel ?
Question 16 options:
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H2
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O2
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H2O
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All of these
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None of these
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Question 17
Thin-film photovoltaic cells are ________.
Question 17 options:
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composed of crystalline silicon
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easy to mass produce
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sensitive to only narrow regions of the visible spectrum
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very expensive to produce
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None of these
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Question 18
Sodium metal is ________.
Question 18 options:
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oxidized in the production of aluminum
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reduced in the production of aluminum
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both oxidized and reduced in the production of aluminum
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neither oxidized nor reduced in the production of aluminum
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Question 19
Which of the following metals would be the easiest to reduce to its native form from an ore?
Question 19 options:
Question 20
How many electrons are transferred from iron atoms to oxygen atoms in the formation of two units of iron hydroxide, Fe(OH)2?
Question 20 options:
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4 electrons
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8 electrons
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16 electrons
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12 electrons
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Question 21
How do you make a proton out of a hydrogen atom?
Question 21 options:
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remove an electron from a hydrogen atom
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remove a proton from a helium nucleus
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let the hydrogen atoms undergo fusion
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let the hydrogen atoms combine to form a hydrogen molecule and eject an electron
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let the hydrogen atoms combine to form a hydrogen molecule and eject a proton
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Question 22
According to the following reaction, which molecule is acting as a base?
H2O + H2SO4 → H3O+ + HSO4-
Question 22 options:
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H2SO4
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H2O
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H3O+
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HSO4-
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None of these
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Question 23
According to the following reaction, which molecule is acting as an acid?
OH- + NH4+→ H2O + NH3
Question 23 options:
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H2O
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NH3
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OH-
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NH4+
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None of these
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Question 24 For the following reaction, identify whether the compound in bold is behaving as an acid or a base.
H3PO4 + H2O ? H2PO4- + H3O+
Question 24 options:
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acid
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base
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neither
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both
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None of these
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Question 25
For the following acid-base reaction, identify what compound is formed in the space marked.
HNO3 + KOH ? ????? + H2O
Question 25 options:
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KNO3
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H3ONO3
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KOH2
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KOH2NO3
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None of these
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Question 26
What is the main characteristic of a strong acid?
Question 26 options:
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It is completely dissociated in water.
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It readily gives up its proton to a base.
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It is corrosive.
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It will damage your skin.
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All of these
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Question 27
What is the hydronium ion concentration in an aqueous solution where the pH = 5?
Question 27 options:
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The hydronium ion concentration equals 1 × 10-9.
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The hydronium ion concentration equals 1 × 10-7.
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The hydronium ion concentration equals 1 × 10-5.
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The hydronium ion concentration equals 1 × 10-3.
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Question 28
Hydrogen chloride is added to a buffer solution of ammonia, NH3, and ammonium chloride, NH4+Cl-. What is the effect on the concentration of ammonia? What is the effect on the concentration of ammonium chloride?
Question 28 options:
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HCl reacts with both the ammonia and ammonium chloride, so the concentration of both decreases.
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HCl reacts with only the ammonium chloride, so the concentration of the ammonium chloride decreases and the concentration of ammonia increases.
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HCl reacts with both the ammonia and ammonium chloride, so the concentration of both increases.
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HCl reacts with only the ammonia, so the concentration of the ammonium chloride increases and the concentration of ammonia decreases.
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Question 29
What would be the best explanation for the fact that most natural water has a pH of about 5.6?
Question 29 options:
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Carbon dioxide reacts with water to form an acid.
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Air contains acid rain particles.
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Minerals that are dissolved in water are often acidic.
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Many salts that dissolve in natural waters make the water basic.
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None of these
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Question 30
Which of the following statements is untrue about oxidation and reduction processes?
Question 30 options:
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An oxidation can happen without a reduction.
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It involves the exchange of electrons.
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Often ions are generated or consumed.
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Electrons are often involved in oxidation and reduction reactions.
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All of these are true.
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Question 31 Which of the following species is the reducing agent?
2 CuBr → 2Cu + Br2
Question 31 options:
Question 32 Hydrogen sulfide, H2S, burns in the presence of oxygen, O2, to produce water, H2O, and sulfur dioxide, SO2. Through this reaction, is sulfur oxidized or reduced?
2 H2S + 3 O2 → 2 H2O + 2 SO2
Question 32 options:
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Sulfur is reduced.
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Sulfur is oxidized
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Sulfur is both oxidized and reduced.
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Sulfur is neither oxidized nor reduced.
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