Ch.4 - Chemical Quantities & Aqueous ReactionsWorksheetSee all chapters
All Chapters
Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds
Additional Problems
Which of the following is the strongest reducing agent?   A) Sn2+(aq) B) Cr3+(aq) C) Sn4+(aq) D) Cr (s) E) Sn (s)
Which of the following is the strongest reducing agent? A) Al(s) B) Zn(s) C) Mg(s) D) Al3+(aq) E) Mg2+(aq)
What is the ratio of oxidizing agent to reducing agent? Ca2+ (aq) + Al (s)   →    Ca (s) + Al 3+ (aq)   a) 2 : 3 b) 3 : 2 c) 1 : 1 d) 4 : 6 
Which species is reduced in the reaction below?        2Al(s) + NO2–(aq) + H2O(l)  + OH-(aq) → 2AlO2–(aq) + NH3(g) a. Al b. NO2– c. H2O(l) d. OH– e. None of the above - this is not an oxidation-reduction reaction.    
What is the ratio of oxidizing agent to reducing agent? _______ Ca2+ (aq) + _______ Al (s) → _______ Ca (s) + _______ Al  3+ (aq)   a) 2 : 3              b) 3 : 2              c) 1: 1              d) 4 : 6 
Consider the following unbalanced oxidation reduction reaction for the question CoO2(s) + Br2(l) → Co3+(aq) + HBrO(aq) Which compounds are involved in the reduction half reaction? (a) CoO2(s), Br2(l) (b) Co3+(aq), HBrO(aq) (c) CoO2(s), Co3+(aq) (d) Br2(l), HBrO(aq) (e) CoO2(s), HBrO(aq) (f) Br2(l), Co3+(aq)
Which element is oxidized and which is reduced in the following reaction: 2 Fe2O3(s) + 3 C(s) → 4 Fe(s) + 3 CO 2(g) a) O is reduced and C is oxidized b) O is oxidized and C is reduced c) Fe is oxidized and O is reduced d) Fe is reduced and C is oxidized e) Fe is oxidized and C is reduced
Which of the following reactants will be capable of oxidizing copper metal to Cu2+ ions? a) NaCl solution b) HCl solution c) AgNO3 solution d) ZnCl2 solution e) Both (b) HCl and (c) AgNO3 solutions
Which one of the following is the strongest oxidizing agent? a) VO2 +              b) VO 2+               c) V 2+               d) V 3+
Which of the following are redox reactions? I. CuSO4 + 2NaOH → Cu(OH) 2 + Na 2SO4   II. 2Al + 3MgSO4 → 3Mg + Al 2(SO4)3   III. 2(NH4)3PO4 + 3Ba(NO3)2 → Ba 3(PO4)2 + 6NH4NO3   IV. 2HNO3 + 3H3AsO3 → 2NO + 3H 3AsO4 + H2O
The following three questions are based on the following reaction: 2 Cr + 3 ClO2 – + 3 H2O → 2 Cr(OH)3 + 3 ClO – The reducing agent is: a) Cr b) ClO2 c) H2O d) Cr(OH)3 e) ClO   The oxidizing agent is: a) Cr b) ClO2 c) H2O d) Cr(OH)3 e) ClO   The oxidation number of chromium on the right hand side of the equation is: a) 2 b) -2 c) 3 d) 4 e) 6
In the following reaction identify the oxidizing agent and the reducing agent: 32 H+ + 14 MnO4 – + 5 N2H4 → 14 Mn2+ + 26 H2O + 10 NO 3 –
Which statement is true for this reaction? Fe (s) + Au(NO3)3 (aq)  → Fe(NO3)3 (aq) + Au (s) a. Metallic iron is the reducing agent b. Gold ion is oxidized c. Metallic iron is reduced d. Nitrate ion (NO3) is the oxidizing agent
Fill in the blanks. A reducing agent is a chemical that causes the _________ of another chemical species by __________electrons to/from the other species. In the process of doing so, the reducing agent gets __________. The answers in order are (a) oxidation, taking, reduced (b) reduction, giving, oxidized  (c) oxidation, giving, oxidized  (d) reduction, taking, reduced  (e) oxidation, taking, oxidized  (f)  reduction, giving, reduced 
In the redox reaction 2 Al + 3 CuSO 4 → 3 Cu + Al 2(SO4)3 A. Al is the reducing agent and each Al atom gains three electrons in the reaction. B. Al is the oxidizing agent and each Al atoms loses three electrons in the reaction. C. CuSO4 is the reducing agent and each Cu atom loses two electrons in the reaction. D. CuSO4 is the oxidizing agent and each Cu atoms gains two electrons in the reaction. E. Cu is the oxidizing agent and each Cu atom loses two electrons in the reaction.
Consider the following oxidation-reduction reaction: MnO2   +   4 HCl   →   Cl 2   +   2 H 2O   +   MnCl 2 What is the oxidizing agent?   1. MnO2           2. HCl           3. Cl   2           4. MnCl 2
Which statement is true for this reaction? Zn (s) + CuSO4 (aq)  → Cu (s) + ZnSO4 (aq) a) Metallic zinc is the reducing agent.  b) Metallic zinc is reduced.  c) Copper ion is oxidized.  d) Sulfate ion is the oxidizing agent. 
Under certain conditions, H2O2 can act as an oxidizing agent; under other conditions, as a reducing agent. What is the best theoretical explanation for this? (A) H2O2 is a good bleaching agent. (B) Peroxides are stronger oxidizing agents than are oxides. (C) H2O2 will decolorize KMnO4 solutions in the presence of an acid and will turn black lead sulfide to a white compound. (D) An atom within a compound can sometimes attain more stable electronic structure gaining or by losing electrons.
Which of the following reactions is an oxidation-reduction reaction? 1. HNO3 (aq) + NaOH (aq) → NaNO3 (aq) + H2O (l) 2. Ca (s) + HCl (aq) → CaCl 2 (aq) + H2 (g) 3. 3 Na2S (aq) + 2 FeCl 3 (aq) → Fe2S3 (s) + 6 NaCl (aq) 4. CO2 (g) + 2 LiOH (aq) → Li 2CO3 (s) + H2O (l)
The activity series are listed in order from most reactive to least reactive. Answer each of the following questions based on the following half reactions: HALF REACTIONS ClO2 (g) + e–→ 2 ClO2– (aq) Cu+ (aq) + e– → Cu (s) Fe3+ (aq) + 3 e– → Fe (s) K+ (aq) + e– → K (s) a) Which is the strongest oxidizing agent?         b) Which is the strongest reducing agent?         c) Could the following reaction occur: Fe3+ (aq) + Cu (s) → Fe (s) + Cu+ (aq)        
Which one of the following is the strongest oxidizing agent? a) VO2 +           b) VO 2+           c) V 2+           d) V 3+
What is the oxidizing agent in the following oxidation–reduction reaction? 2 H+ + 3 H2O + As2O3 + 2 NO3– → 2 H3AsO4  + 2 HNO2 A. H+ B. As2O3 C. NO3– D. H3AsO4 E. HNO2
Consider the following chemical equation,             2 Al3+(aq) + 2 Fe(s)  →  2 Al(s) + 3 Fe2+(aq) identify the reducing agent.   A) Al3+ B) Fe C) Al D) Fe2+ E) This is not an oxidation-reduction reaction.
Which experimental evidence clearly illustrates the oxidizing property of chlorine, Cl2? (A) its liberation at the anode during the electrolytics of sodium chloride solution (B) the reaction of chlorine with sodium bromide solution, resulting in the displacement of bromine (C) the use of chlorates as oxidizing agents in the manufacture of matches (D) its moderate solubility in aqueous solution
Consider the chemical reaction: 2 SO2 (g) → SO(g) + SO3 (g) Determine if the sentence below is true or false The reaction is a redox reaction.
Chemists use some important terminology to describe the movement of electrons. In REDOX reactions we have the movement of electrons from one reactant to another.   
In the following reaction identify the oxidizing agent and the reducing agent:   
Consider the following reaction: Cu + 2 AgNO3 → Cu(NO3)2 + 2 Ag   a. Cu is oxidized b. Ag+ is reduced c. Cu is the reducing agent d. All of the following is correct 
You may have heard that "antioxidants" are good for your health.Is an "antioxidant" an oxidizing agent or a reducing agent?
Titration of an acidic solution of Na2C2O4 with KMnO4(aq). The balanced chemical equation for this reaction is: 16 H+(aq) + 2 MnO4-(aq) + 5 C2O42-(aq)  →  2 Mn2+(aq) + 8 H2O(l) + 10 CO2(g) Which species is the reducing agent?
Treatment of gold metal with BrF3 and KF produces Br2 and KAuF4, a salt of gold.Identify the oxidizing agent in this reaction.
Treatment of gold metal with BrF3 and KF produces Br2 and KAuF4, a salt of gold.Identify the reducing agent in this reaction.
By using the data in Appendix E in the textbook, determine whether each of the following substances is likely to serve as an oxidant or a reductant.Cl2 (g).
By using the data in Appendix E in the textbook, determine whether each of the following substances is likely to serve as an oxidant or a reductant.MnO4 - (aq, acidic solution).
By using the data in Appendix E in the textbook, determine whether each of the following substances is likely to serve as an oxidant or a reductant.Ba(s).
By using the data in Appendix E in the textbook, determine whether each of the following substances is likely to serve as an oxidant or a reductant.Zn(s).
Indicate whether each of the following statements is true or false.For the reaction Fe3 + (aq) + Co2 + (aq)  →  Fe2 + (aq) + Co3 + (aq),Fe3 + (aq) is the reducing agent and Co2 + (aq) is the oxidizing agent.
Explain how a redox reaction involves electrons in the same way that an acid-base reaction involves protons.
In the Brønsted-Lowry concept of acids and bases, acid–base reactions are viewed as proton-transfer reactions. The stronger the acid, the weaker is its conjugate base.If we were to think of redox reactions in a similar way, what particle would be analogous to the proton?
Potassium superoxide, KO2, is often used in oxygen masks (such as those used by firefighters) because KO2 reacts with CO2 to release molecular oxygen. Experiments indicate that 2 mol of KO2 (s) react with each mole of CO2(g).What elements are being oxidized and reduced?
What is an oxidation-reduction reaction?
How can oxidation states be used to identify redox reactions?
What happens to a substance when it becomes oxidized? Reduced?
In a redox reaction, which reactant is the oxidizing agent? The reducing agent?
Give the basic definitions of oxidation and reduction and explain the basic procedure for balancing redox reactions.
Indicate whether each of the following statements is true or false.If there are no changes in the oxidation state of the reactants or products of a particular reaction, that reaction is not a redox reaction.
Oxidation of zinc by hydrochloric acid.Explain the vigorous bubbling in the beaker on the right.
Oxidation of zinc by hydrochloric acid.Explain the formation of steam above that beaker.
Titration of an acidic solution of Na2C2O4 with KMnO4(aq). The balanced chemical equation for this reaction is: 16 H+(aq) + 2 MnO4-(aq) + 5 C2O42-(aq)  →  2 Mn2+(aq) + 8 H2O(l) + 10 CO2(g) Which species is reduced in this reaction?
Disulfides are compounds that have S-S bonds, like peroxides have O-O bonds. Thiols are organic compounds that have the general formula R-SH, where R is a generic hydrocarbon. The SH- ion is the sulfur counterpart of hydroxide, OH-. Two thiols can react to make a disulfide, R-S-S-R.If you react two thiols to make a disulfide, are you oxidizing or reducing the thiols?
Aqueous solutions of ammonia (NH3) and bleach (active ingredient NaOCl) are sold as cleaning fluids, but bottles of both of them warn: "Never mix ammonia and bleach, as toxic gases may be produced." One of the toxic gases that can be produced is chloroamine, NH2Cl.Is Cl oxidized, reduced, or neither, upon the conversion of bleach to chloramine?
Aqueous solutions of ammonia (NH3) and bleach (active ingredient NaOCl) are sold as cleaning fluids, but bottles of both of them warn: "Never mix ammonia and bleach, as toxic gases may be produced." One of the toxic gases that can be produced is chloroamine, NH2Cl.Is N oxidized, reduced, or neither, upon the conversion of ammonia to nitrogen trichloride?
The Haber process is the principal industrial route for converting nitrogen into ammonia: N2 (g) + 3H2 (g)  →  2NH3 (g).What is being oxidized, and what is being reduced?
What is meant by the term oxidation?
What is meant by the term oxidant?
What is meant by the term oxidizing agent?
Indicate whether each of the following statements is true or false.If something is oxidized, it is formally losing electrons.
In which group can each substance act as an oxidizing agent?A. Cl2, MnO2, CuB. Cl2, MnO4–, Cu2+C. Cl-, MnO4–, Cu+D. Cl2, Mn, Cu2+
Which element is oxidized and which is reduced in the following reactions?(a) N2 (g) + 3 H2 (g) → 2 NH3 (g) 
Which element is oxidized and which is reduced in the following reactions?(b) 3 Fe(NO3)2 (aq) + 2 Al (s) → 3 Fe (s) + 2 Al(NO 3)3 (aq)
Which element is oxidized and which is reduced in the following reactions?(c) Cl2 (aq) + 2 NaI (aq) → I 2 (aq) + 2 NaCl (aq)
Consider the redox equation shown below and determine which of the statements(s) that follow is/are correct.SeO32-(aq) + Cl2(aq) → SeO42-(s) + Cl-(aq)i.  SeO42- is the reducing agent.ii. Cl2 is the oxidizing agent.iii. Cl- is the oxidizing agent.A. i onlyB. ii onlyC. iii onlyD. i and iiiE. ii and iii
Identify the oxidation and reduction steps in the following reaction:4Fe +3O2 → 2Fe2O3A.  Oxidize: O2 → 2 O2− + 2 e−                  Reduced: Fe → Fe  3+ + 3 e−B.  Oxidize: Fe → Fe2+ + 2 e−                    Reduced: O2 → 2 O2− + 4 e−C.  Oxidize: Fe → Fe3+ + 3 e−                    Reduced: 4 e− + O2 → 2 O2− D.  Oxidize: Fe → Fe3+ + 3 e−                      Reduced: O2 → 2 O2− + 4 e−E.  Oxidize: O2 → 2 O2− + 4 e−                  Reduced: Fe → Fe3+ + 3 e− 
Which element is oxidized and which is reduced in the following reactions?(d) PbS (s) + 4 H2O2 (aq) → PbSO4 (s) + 4 H2O (l) 
Which of the following describe oxidation? A. Increase in oxidation number B. Loss of electrons C. Loss of neutrons D. Gain of protons E. Both A and B
Which element is oxidized and which is reduced in the following reaction?(a) N2(g) + 3 H2(g) → 2 NH3(g) 
Which element is oxidized and which is reduced in the following reactions?(b) 3 Fe(NO3)2(aq) + 2 Al(s) → 3 Fe(s) + 2 Al(NO 3)3(aq) 
Using the table below, which substance can oxidize I – (aq) to I2 (s)?a) Br2 (l)b) Ni2+ (aq)c) Ag (s)d) Cu2+ (aq)e) More than one of the above
Which of the following are redox reactions? For those that are, indicate which element is oxidized and which is reduced. For those that are not, indicate whether they are precipitation or acid-base reactions.(c) Sr(NO3)2(aq) + H2SO4(aq) → SrSO4(s) + 2 HNO3(aq)  
Aluminum metal reacts with oxygen gas (O2) to form aluminum oxide according to the equation 4Al + 3O2   → 2Al2O3 Aluminum is reduced a) True b) False
Which of the following are redox reactions? For those that are, indicate which element is oxidized and which is reduced. For those that are not, indicate whether they are precipitation or acid-base reactions.(d) 4 Zn(s) + 10 H+(aq) + 2 NO3-(aq) → 4 Zn2+(aq) + N2O(g) + 5 H2O(I) 
Which is reduced in the following reaction?Fe2O3 + 3 H2 → 2 Fe + 3 H2Oa. Fe2O3b. H2Oc. Fed. H2e. None of the above 
Which of the following is an oxidation-reduction reaction?  Ba(C2H3O2)2 (aq) + Na2SO4 (aq) → BaSO4 (s) + 2NaC2H3O2 (aq) H2CO3 (aq) + Ca(NO3)2 (aq) → 2HNO3 (aq) + CaCO3 (s) Cu (s) + 2AgNO3 (aq) → 2Ag (s) + Cu(NO3)2 (aq) AgNO3 (aq) + HCl (aq) → AgCl (s) + HNO3 (aq) HCl (aq) + NaOH (aq) → H2O (l) + NaCl (aq)
Which substance serves as the reducing agent in the following unbalanced reaction that occurs in acid:Cr2O72– (aq) + Ni (s) → Ni 2+ (aq) + 2 Cr 3+ (aq) (acidic solution) a) H+ (aq)b) Cr2O72– (aq)c) Ni (s)d) Ni2+ (aq)e) H2O (l) 
In the two reactions below, which atom is oxidized?Zn(s) + H2SO4(aq) → ZnSO4(aq) + H2(g)H2O2 + CaS → CaSO4 + H2O (not balanced)a. Zn and Sb. H and Sc. Zn and Hd. S and Se. none of these
Which of the following statements is true of an oxidizing agent.a) A strong oxidizing agent must be a weak reducing agentb) An oxidizing agent facilitates the oxidation of another substancec) An oxidizing agent is itself oxidized during a redox reactiond) Both statements b and c are truee) All of the above statements are true
Which one of the following is NOT a redox reaction?a. 2H2O2(aq) → 2H2O(l) + O2(g)b. 2 Al(s) + Fe2O3(s)→ Al2O3(s) + 2Fe(s)c. BaCl2(aq) +K2CrO4(aq) →BaCrO4(aq) + 2 KCl(aq)d. 2 H2O(g) → 2H2(g) + O2(g)e. N2(g) + 3 H2(g) → 2NH3(g)
What element is being oxidized in the following redox reaction?H2O2(l) + ClO2(aq) → ClO21-(aq) + O2(g)A) HB) OC) CD) ClE) This is not a Redox Rxn
Which statement about this redox reaction is correct?2 ZnS(s) + 3 O2(g) → 2 ZnO(s) + 2SO2(g)A. oxygen is reducedB. Sulfur gains electronsC. Oxygen is the reducing agentD. Sulfur us the oxidizing agent
15. Which of the following reactions is/are redox reactions?(1) K2CrO4 + BaCl2 → BaCrO4 + 2KCl(2) Ag+ + Br− → AgBr(3) Cu + S → CuS      A) only reaction (1)     B) only reaction (2)     C) only reaction (3)             D) both reactions (1) and (3)            E) both reactions (2) and (3)
Is the following reaction an example of a redox reaction?Cr2O72– (aq) + H2O (l) ⇄ 2 CrO 42– (aq) + 2 H+ (aq) a) Yes, Cr is oxidized and oxygen is reducedb) Yes, Cr is oxidized and hydrogen is reducedc) Yes, oxygen is oxidized and Cr is reducedd) Yes, hydrogen is oxidized and Cr is reducede) No, neither hydrogen, oxygen, nor Cr are oxidized or reduced
Which element is oxidized in this reaction?2CuO + C → 2Cu + CO 2Enter the chemical symbol of the element.
Specify which of the following equations represent oxidation–reduction reactions, and indicate the oxidizing agent, the reducing agent, the species being oxidized, and the species being reduced.a. CH4(g) + H2O(g) → CO(g) + 3H2(g)
Specify which of the following equations represent oxidation–reduction reactions, and indicate the oxidizing agent, the reducing agent, the species being oxidized, and the species being reduced.b. 2AgNO3(aq) + Cu(s) → Cu(NO3)2(aq) + 2Ag(s) 
Identify which has been oxidized and reduced. Then identify the oxidizing agent in the following:2 NH3 + OCl - → N2H4 + H2O + Cl -Oxidized: ______________                     Reduced: ____________Oxidizing Agent: ____________              Reducing Agent: _____________
Specify which of the following equations represent oxidation–reduction reactions, and indicate the oxidizing agent, the reducing agent, the species being oxidized, and the species being reduced.c. Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g) 
Specify which of the following equations represent oxidation–reduction reactions, and indicate the oxidizing agent, the reducing agent, the species being oxidized, and the species being reduced.d. 2H+(aq) + 2CrO42-(aq) → Cr2O72-(aq) + H2O(l) 
Consider the reaction between oxygen (O2) gas and magnesium metal to form magnesium oxide. Using oxidation states, how many electrons would each oxygen atom gain, and how many electrons would each magnesium atom lose? How many magnesium atoms are needed to react with one oxygen molecule? Write a balanced equation for this reaction.
Which statement is most true of the reaction:Bi2S3 (s) + 3 H+ (aq) → 2 Bi3+ (aq)+ 3 H2S (aq)a) This is a redox reaction because Bi2S3 serves as the oxidizing agent and H+ as the reducing agentb) This is a redox reaction because Bi2S3 serves as the reducing agent and H+ as the oxidizing agentc) This is a redox reaction because Bi is oxidized and H is reducedd) Both a and c are truee) None of the above are true because the reaction is not a redox reaction  
Choose the appropriate labels to their respective targets. Indicate whether a reactant is a reducing agent or an oxidizing agent. 
What element is undergoing oxidation (if any) in the following reaction?CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(g)a) Ob) Hc) Cd) both C and He) None of the elements is undergoing oxidation 
Which one of the following is not a redox reaction?a. Al(OH)4-(aq) + 4H +(aq) → Al 3+(aq) + 4H 2O(l)b. C6H12O6(s) + 6O2(g) → 6CO2(g) + 6H2O(l)c. Na 6FeCl8(s) + 2Na(l) → 8NaCl(s) + Fe(s)d. 2H2O2(aq) → 2H2O(l) + O2(g)e. CO2(g) + H2(g) → CO(g) + H3O(g)
Which is the reducing agent in the (unbalanced) reaction?S2O32-(aq) +  I2(aq) +  H+(aq)  →  I1-(aq)  + S4O62-(aq)            A)  S2O32-    B)  H+    C) I 2      D)  S4O62-  E)  I1- 
Differentiate between the following terms.a. species reduced versus the reducing agent
Which element is reduced in this reaction?2KMnO4 + 3Na2SO3 + H2O → 2MnO2 + 3Na2SO4 + 2KOHEnter the chemical symbol of the element.
Differentiate between the following terms.b. species oxidized versus the oxidizing agent
Which element is oxidized and which is reduced in the following reactions? Express your answers as chemical symbols separated by a comma. Enter the oxidized element first.a. N2(g) + 3H2(g) → 2NH3(g)b. Cl2(aq) + 2NaI(aq) → I2(aq) + 2NaCl(aq)c. PbS(s) + 4H2O2(aq) → PbSO4(s) + 4H2O(l)
In this reaction, which substance behaves as the oxidizing agent?Pb (s) + PbO2 (s) + 2 H2SO4 → 2 PbSO4 (s) + 2 H2O (l)(A) Pb(B) PbSO4(C) PbO2(D) H2SO4
Which element is the oxidizing agent in this reaction?ZnO+C→Zn+COEnter the chemical symbol of the element. 
Complete and balance the equation for this reaction in acidic solution.Zn(s) + NO3- → Zn2+ + NH4+i) Which element was Oxidized ?ii) Which element was reduced?iii) Which species was the oxidizing agent?iv) Which species was the reducing agent?
What is the ratio of oxidizing agent to reducing agent?_______ Ca2+ (aq) + _______ Al (s) → _______ Ca (s) + _______ Al  3+ (aq) a) 2 : 3              b) 3 : 2              c) 1: 1              d) 4 : 6 
Which element is oxidized and which is reduced in the following reaction?N2(g) + 3H2(g) → 2NH3(g)
Which element is oxidized and which is reduced in the following reaction?3Fe(NO3)2(aq) + 2Al(s) → 3Fe(s) + 2Al(NO 3)3(aq)
Which element is oxidized and which is reduced in the following reaction?Cl2(aq) + 2NaI(aq) → I 2(aq) + 2NaCl(aq)
Which element is oxidized and which is reduced in the following reaction?PbS(s) + 4H2O2(aq) → PbSO4(s) + 4H2O(l)
What is the oxidizing agent in the (unbalanced) reaction?Cu(s) + H+(aq) + NO3-(aq) → NO(g) + H2O(l) + Cu2+(aq)A) CuB) H+C) NO3-D) NOE) Cu2+
Which one of the following is not a redox reaction?a. 2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)b. H2(g) + Cl2(g) → 2HCl(g)c. 2H2O2(aq) → 2H2O(l) + O2(g)d. Fe2O3(s) + 3H2SO4(aq) → Fe2(SO4)3(aq) + 3H2O(l)e. 2KMnO4(aq) + 10FeSO4(aq) + 8H2SO4(aq) → K2SO4(aq) + 2MnSO4(aq) + 5Fe2(SO4)3(aq) + 8H2O(l)
Which of the following reactions would be classified as oxidation-reduction?a. 2Na(s) + Cl 2(g) → 2NaCl(s)b. Na(s) + CuCl(aq) → NaCl(aq) + Cu(s)c. NaCN(aq) + CuCl(aq) → NaCl(aq) + CuCN(s)
Identify the oxidizing agent and the reducing agent for the following reaction.N2 + 6Li → 2Li 3Na. N2 is the oxidizing agent and Li is the reducing agent.b. Li is the oxidizing agent and N 2 is the reducing agent.
Which of the following is True?A) reduction results in a decrease in the oxidation numberB) reduction is the loss of electronsC) reduction occurs at the cathodeD) an increase in the oxidation number occurs only at the cathodeE) both A and C
Identify the oxidizing agent and the reducing agent for the following reaction.2H2S + SO2 → 3S + 2H 2Oa. H2S is the oxidizing agent and SO2 is the reducing agent.b. SO2 is the oxidizing agent and H2S is the reducing agent. 
Identify the oxidizing agent and the reducing agent for the following reaction.C3H4 + 2H2 → C3H8a. C3H4 is the oxidizing agent and H2 is the reducing agent.b. H2 is the oxidizing agent and C3H4 is the reducing agent.
What element is being oxidized in the following redox reaction? Cr2O72-(aq) + Mn2O3(s) → Cr3+(aq) + MnO2(aq)A) OB) CrC) MnD) ClE) both Mn and Cl
Identify the oxidizing agent and the reducing agent for the following reaction.Ag+ + Ti 3+ → Ag + Ti 4+a. Ag+ is the oxidizing agent and Ti 3+ is the reducing agent.b. Ti 3+ is the oxidizing agent and Ag+ is the reducing agent.
Which element is reduced in this reaction?16H+ + 2Cr2O72- + C2H5OH → 4Cr3+ + 11H2O + 2CO2 
Consider the following reaction equations. Which is/are redox reactions?i. Cr(C2H3O2)2 (aq) + 2 NaOH (aq) → 2 NaC 2H3O2 (aq) + Cr(OH)2 (s)ii. Fe (s) + 4 HNO3 (aq) → Fe(NO3)2 (aq) + 2 NO2 (g) + 2 H2O (l)iii. B2O3 (s) + 6 KOH (aq) → 2 K 3BO3 (aq) + H2O (l) A. i onlyB. ii onlyC. iii onlyD. i and iiE. ii and iii
Reduction involves which of the following?A) decrease in oxidation numberB) loss of electronsC) gain of electronsD) increase in oxidation numberE) both A and C
Determine whether each of the following changes represents oxidation or reduction.
What element is being oxidized in the following redox reaction?Cr(OH)4-(aq) + ClO-(aq) → CrO42-(aq) + Cl-(aq)A) OB) CrC) HD) Cl 
Consider the reaction2 Fe3+ (aq) + 2 I– (aq)   ⇌   2 Fe2+ (aq) + I2 (aq)Which statement for the reaction is true? A. Fe3+ is oxidizedB. Fe3+ increases in oxidation numberC. Fe3+ is reducedD. I– is reduced 
In the chemical reaction, Zn (s) + CuSO4 (aq)   ⇌   ZnSO4 (aq) + Cu (s), A. Metallic zinc is the reducing agentB. Metallic zinc is reducedC. Copper ion is oxidizedD. Sulfate ion is the oxidizing agent 
Which one of the following is  not a redox reaction?a) 2H2O2(aq) → 2H2O(l) + O2(g) b) C6H12O6(s) + 6O2(g) → 6CO2(g) + 6H2O(l)c) Na6FeCl8(s) + 2Na(l) → 8NaCl(s) + Fe(s)d) Al(OH)4-(aq) + 4H+(aq) → Al3+(aq) + 4H2O(l)e) CO2(g) + H2(g) → CO(g) + H2O(g)               
Which element is reduced in this reaction?Cr2O72− + 3HNO2 + 5H+ → 2Cr3+ + 3NO3−+4H2OEnter the chemical symbol of the element.
Which element is oxidized in this reaction? FeO + CO → Fe + CO 2 Enter the chemical symbol of the element.  
Which of the following is the strongest reducing agent?a. Ca2+(aq)b. Li+(aq)c. Ca(s)d. Na(s)e. K(s)
Which element is reduced in this reaction?16H+ + 2Cr2O72- + C2H5OH → 4Cr3+ + 11H2O + 2CO2
Define oxidation and reduction in terms of (a) electron transfer
Which element is oxidized and which is reduced in the following reaction? N2(g) + 3H2(g) → 2NH3(g) Express your answer as chemical symbols separated by a comma.
Which element is oxidized and which is reduced in the following reaction? 3Fe(NO3)2(aq) + 2AI(s) → 3Fe(s) + 2AI(NO 3)3(aq)Express your answer as chemical symbols separated by a comma.
Which element is oxidized and which is reduced in the following reaction? PbS(s) + 4H2O2(aq) → PbSO4(s) + 4H2O(l)Express your answer as chemical symbols separated by a comma.
Which circled region of the periodic table shown here contains the most readily oxidized elements? Which contains the least readily oxidized?
Which element is reduced in this reaction?2KMnO4 + 3Na2SO3 + H2O → 2MnO2 + 3NaSO4 + 2KOH
Consider the following balanced redox reaction: 3CuO(s) + 2NH3(aq) → N2(g) + 3H2O(l) + 3Cu(s)Which of the following statements is true?a) CuO(s) is the oxidizing agent and copper is oxidized.b) CuO(s) is the oxidizing agent and copper is reduced.c) CuO(s) is the reducing agent and copper is oxidized.d) CuO(s) is the reducing agent and copper is reduced.e) CuO(s) is the oxidizing agent and N2(g) is the reducing agent.
Which statement about this redox reaction is correct? Fe(s) + Cu2+ (aq) → Cu(s) + Fe2+ (aq) A. Cu2+ is oxidized B. Cu2+ gains in oxidation number C. Cu2+ is reduced D. Fe is reduced
Which one of the following reactions is not an oxidation-reduction reaction?a. N2(g) + 3H2(g) → 2NH3(g)b. NH4NO2(s) → N2(g) + 2H2O(l)c. Cu(s) + 2Ag+(aq) → Cu2+(aq) + 2Ag(s)d. C2H4(g) + H2(g) → C2H6(g)e. 2CrO42-(aq) + 2H+(aq) → Cr2O72-(aq) + H2O(l)
Which of the following statement(s) is/are correct regarding the following reaction?      SO42- + Br2 → S2O32- + BrO3- i. SO42- is the oxidizing agent ii. The oxidation number of Br in BrO3- is +6 iii. BrO3- is the reducing agent A) i only B) ii only C) iii only D) ii and iii E) i and iii
Which of the following metals is the best reducing agent? a. Ni b. Mg c. Fe d. Co
Consider the following reaction - NaI + 3HOCl → NaIO3 + 3HCl Is NaI the reducing agent? a. True b. False
Which element is oxidized in this reaction? Fe2O3 + 3CO → 2Fe + 3CO2
Which substance is the reducing agent  in this reaction?2KMnO4 + 3Na2SO3 + H2O → 2MnO2 + 3Na2SO4 + 2KOH
Which substance is the oxidizing agent in this reaction? 2CuO + C → 2Cu + CO2  
Which substance is the reducing agent in this reaction?   16H+ + 2Cr2O72− + C2H5OH → 4Cr3+ + 11H2O + 2CO2
Which of the following metals is the best reducing agent and which is the worst? Mn, Al, Ni, Cr
Which of the following metals is the best reducing agent?a. Cob. Lac. Nid. Fe
a. Which element is reduced in this reaction? 2Cr(OH)3 + 3OCl− + 4OH− → 2CrO42− + 3Cl− + 5H2O b. Which element is oxidized in this reaction? 2CuO + C → 2Cu + CO 2 c. Write the net ionic equation for the following reaction: FeO(s) + 2HClO4(aq) → Fe(ClO4)2(aq) + H2O(l)
Mixtures of CaCl2 and NaCl are used to melt ice on roads. A dissolved 1.9348-g sample of such a mixture was analyzed by using excess Na2C2O4 to precipitate the Ca2+ as CaC2O4. The CaC2O4 was dissolved in sulfuric acid, and the resulting H2C2O4 was titrated with 37.68 mL of 0.1019 M KMnO4 solution.What is the oxidizing agent?
Mixtures of CaCl2 and NaCl are used to melt ice on roads. A dissolved 1.9348-g sample of such a mixture was analyzed by using excess Na2C2O4 to precipitate the Ca2+ as CaC2O4. The CaC2O4 was dissolved in sulfuric acid, and the resulting H2C2O4 was titrated with 37.68 mL of 0.1019 M KMnO4 solution.What is the reducing agent?
Identify the oxidizing agent and the reducing agent for each reaction:a. Al(s) + 3 Ag+(aq) → Al3+(aq) + 3 Ag(s)b. SO3(g) + H2O(l) → H2SO4(aq)c. Ba(s) + Cl2(g) → BaCl2(s)d. Mg(s) + Br2(l) → MgBr2(s)
Nitric acid, a major industrial and laboratory acid, is produced commercially by the multistep Ostwald process, which begins with the oxidation of ammonia:Step 1. 4 NH3(g) + 5 O2(g) ⟶ 4 NO(g) +6 H2O(l) Step 2. 2 NO(g) + O2(g) ⟶ 2 NO2(g) Step 3. 3 NO2(g) + H2O(l) ⟶ 2 HNO3(l) + NO(g) What are the oxidizing and reducing agents in each step?
At liftoff, a space shuttle uses a solid mixture of ammonium perchlorate and aluminum powder to obtain great thrust from the volume change of solid to gas. In the presence of a catalyst, the mixture forms solid aluminum oxide and aluminum trichloride and gaseous water and nitrogen monoxide.Write a balanced equation for the reaction, and identify the reducing and oxidizing agents.
Sodium reacts with water according to the reaction:2 Na(s) + 2 H2O(l) → 2 NaOH(aq) + H2(g)Identify the oxidizing agent.
You may want to reference(Pages 860 - 867)Section 20.4 while completing this problem.By using the data in Appendix E, determine whether each of the following substances is likely to serve as an oxidant or a reductant:(a) Ce3+ (aq)
Identify the oxidizing and reducing agents in the following reactions:5 H2C2O4 (aq) + 2 MnO4− (aq) + 6 H+ (aq) ⟶ 2 Mn2+(aq) + 10 CO2(g) + 8 H2O(l)
Identify the oxidizing and reducing agents in the following reactions:3 Cu(s) + 8 H+(aq) + 2 NO3−(aq) ⟶ 3 Cu2+(aq) + 2 NO(g) + 4 H2O(l)
Identify the oxidizing and reducing agents in the following reactions:Sn(s) + 2 H+(aq) ⟶ Sn2+(aq) + H2(g) 
What is the reducing agent in the following reaction?2 Br-(aq) + H2O2(aq) + 2 H+(aq)  →  Br2(aq) + 2 H2O(l)
Identify the oxidizing and reducing agents in the following reactions:2 H+(aq) + H2O2(aq) + 2 Fe2+(aq) ⟶ 2 Fe3+(aq) + 2 H2O(l)
Identify the oxidizing and reducing agents in the following reactions:8 H+(aq) + 6 Cl−(aq) + Sn(s) + 4 NO3 −(aq) ⟶ SnCl6 2−(aq) + 4 NO2(g) + 4 H2O(l)
Identify the oxidizing and reducing agents in the following reactions:2 MnO4 −(aq) + 10 Cl−(aq) + 16 H+(aq) ⟶ 5 Cl2(g) + 2 Mn2+(aq) + 8 H2O(l)
Identify the oxidizing and reducing agents in the following reactions: 8 H+(aq) + Cr2O7 2−(aq) + 3 SO3 2−(aq) ⟶ 2 Cr3+(aq) + 3 SO4 2−(aq) + 4 H2O(l)
Identify the oxidizing and reducing agents in the following reactions:NO3 −(aq) + 4 Zn(s) + 7 OH−(aq) + 6 H2O(l) ⟶ 4 Zn(OH)4 2−(aq) + NH3(aq)
The active agent in many hair bleaches is hydrogen peroxide. The amount of H2O2 in 14.8 g of hair bleach was determined by titration with a standard potassium permanganate solution:2 MnO4 −(aq) + 5 H2O2(aq) + 6 H+(aq) ⟶ 5 O2(g) + 2 Mn2+(aq) + 8 H2O(l) What is the reducing agent in the redox reaction?
S4O62−(aq) + 2I−(aq) ⟶ I2(s) + S2O32−(aq)        ΔG° = 87.8 kJ/mol(a) Identify the oxidizing and reducing agents.
Identify the oxidizing agent and the reducing agent for the following reaction:2Li(s) +Cl2(g) → 2LiCl(s)
Identify the oxidizing agent and the reducing agent for the following reaction:2Al(s) + 3Sn2+(aq) → 2Al3+(aq) + 3Sn(s)
Identify the oxidizing agent and the reducing agent for the following reaction:C(s) + O2(g) → CO2(g)
Discuss the following conclusion from a study of redox reactions: The sulfide ion functions only as a reducing agent.
Discuss the following conclusion from a study of redox reactions: The sulfate ion functions only as an oxidizing agent.
What is meant by the term reductant?
Discuss the following conclusion from a study of redox reactions: Sulfur dioxide functions as an oxidizing or a reducing agent.
What is meant by the term reducing agent?
Consider the following balanced redox reaction:16H+ (aq) + 2MnO4− (aq) + 10Cl − (aq) ⟶ 2Mn 2+ (aq) + 5Cl 2 (g) + 8H2O (l)(c) Which species is the oxidizing agent?
Consider the following balanced redox reaction:16H+ (aq) + 2MnO4− (aq) + 10Cl − (aq) ⟶ 2Mn 2+ (aq) + 5Cl 2 (g) + 8H2O (l)(d) Which species is the reducing agent?
At 900oC titanium tetrachloride vapor reacts with molten magnesium metal to form solid titanium metal and molten magnesium chloride.Which substance is the reductant and which is the oxidant?
Aqua regia, a mixture of concentrated HNO 3 and HCl, was developed by alchemists as a means to “dissolve” gold. The process is a redox reaction with this simplified skeleton reaction:Au(s) + NO3−(aq) + Cl−(aq) ⟶ AuCl4−(aq) + NO2(g)(b) What are the oxidizing and reducing agents?
Consider the reaction:Zn(s) + Fe2+(aq) → Zn2+(aq) + Fe(s)Which is the oxidizing agent?
Consider the reaction:Zn(s) + Fe2+(aq) → Zn2+(aq) + Fe(s)Which is the reducing agent?
Identify the oxidizing agent and the reducing agent for 4Li(s) + O2(g) → 2Li2O(s).
Identify the oxidizing agent and the reducing agent for Mg(s) + Fe2+(aq) → Mg2+(aq) + Fe(s).
Determine if the following is an oxidation–reduction reaction, and identify the oxidizing agent, the reducing agent, the substance being oxidized, and the substance being reduced:Al(OH)-4 (aq) → AlO-2 (aq) + 2 H2O (l)
Determine if the following equation represent an oxidation–reduction reaction, and indicate the oxidizing agent, the reducing agent, the species being oxidized, and the species being reduced:CH4 (g) + H2O (g) → CO (g) + 3 H2 (g)
Determine if the following equation represent an oxidation–reduction reaction, and indicate the oxidizing agent, the reducing agent, the species being oxidized, and the species being reduced:2 AgNO3 (aq) + Cu (s) → Cu(NO3)2 (aq) + 2 Ag (s)
Determine if the following equation represent an oxidation–reduction reaction, and indicate the oxidizing agent, the reducing agent, the species being oxidized, and the species being reduced:Zn (s) + 2 HCl (aq) → ZnCl2 (aq) + H2 (g)
Which of the following reactions are redox reactions?a. Al(s) + 3 Ag+(aq) → Al3+(aq) + 3 Ag(s)b. SO3(g) + H2O(l) → H2SO4(aq)c. Ba(s) + Cl2(g) → BaCl2(s)d. Mg(s) + Br2(l) → MgBr2(s)
Determine if the following equation represent an oxidation–reduction reaction, and indicate the oxidizing agent, the reducing agent, the species being oxidized, and the species being reduced:2 H+ (aq) + 2 CrO42- (aq) → Cr2O72- (aq) + H2O (l)
In 1995, Mario Molina, Paul Crutzen, and F. Sherwood Rowland shared the Nobel Prize in chemistry for their work on atmospheric chemistry. One reaction sequence they proposed for the role of chlorine in the decomposition of stratospheric ozone (we’ll see another sequence in Chapter 16) is(1) Cl(g) + O3(g) ⟶ ClO(g) + O2(g) (2) ClO(g) + ClO(g) ⟶ Cl2O2(g) (3) Cl2O2(g) light ⟶ 2 Cl(g) + O2(g) Over the tropics, O atoms are more common in the stratosphere:(4) ClO(g) + O(g) ⟶ Cl(g) + O2(g) Which, if any, of these are oxidation-reduction reactions?
Classify the following as acid-base reactions or oxidation-reduction reactions:(b) 2Na(s) + 2HCl(aq) ⟶ 2NaCl(aq) + H2(g)
Classify the following as acid-base reactions or oxidation-reduction reactions:(c) Mg(s) + Cl2(g) ⟶ MgCl2(s)
Classify the following as acid-base reactions or oxidation-reduction reactions:(e) K3P(s) + 2O2(g) ⟶ K3PO4(s)
True or false.(a) If a substance is oxidized, it is gaining electrons.
You may want to reference (Pages 138 - 144) Section 4.4 while completing this problem.Complete the sentences to explain why each statement is true or false.(a) Oxidation can occur without oxygen.
Uranium hexafluoride, UF6, is processed to produce fuel for nuclear reactors and nuclear weapons. UF6 is made from the reaction of elemental uranium with ClF3, which also produces Cl2 as a by-product.Is this a redox reaction?
Silver can be separated from gold because silver dissolves in nitric acid while gold does not. Is the dissolution of silver in nitric acid an acid-base reaction or an oxidation-reduction reaction? Explain your answer.
You may want to reference (Pages 138 - 144) Section 4.4 while completing this problem.Which of the following are redox reactions? (a) P4(s) + 10HClO(aq) + 6H2O(l) →  4H3PO4(aq) + 10HCl(aq)(b) Br2(l) + 2K(s) → 2KBr(s)(c) CH3CH2OH(l) + 3O2(g) → 3H2O(l) + 2CO2(g)(d) ZnCl2(aq) + 2NaOH(aq) → Zn(OH)2(s) + 2NaCl(aq)
For each of the following balanced half-reactions, determine whether an oxidation or reduction is occurring.(a) Fe3+ + 3e− ⟶ Fe 
For each of the following balanced half-reactions, determine whether an oxidation or reduction is occurring.(b) Cr ⟶ Cr3+ + 3e− 
For each of the following balanced half-reactions, determine whether an oxidation or reduction is occurring.(c) MnO4 2− ⟶ MnO4 − + e− 
For each of the following balanced half-reactions, determine whether an oxidation or reduction is occurring.(d) Li+ + e− ⟶ Li
For each of the following unbalanced half-reactions, determine whether an oxidation or reduction is occurring.(a) Cl− ⟶ Cl2 
Indicate which reactions are redox reactions.(a) 2 Li(s) + Cl2(g) → 2 LiCl(s)(b) 2 Al(s) + 3 Sn2+(aq) → 2 Al3+(aq) + 3 Sn(s)(c) Pb(NO3)2(aq) + 2 LiCl(aq) → PbCl2(s) + 2 LiNO3(aq)(d) C(s) + O2(g) → CO2(g)
For each of the following unbalanced half-reactions, determine whether an oxidation or reduction is occurring.(b) Mn2+ ⟶ MnO2 
For each of the following unbalanced half-reactions, determine whether an oxidation or reduction is occurring.(c) H2 ⟶ H+ 
For each of the following unbalanced half-reactions, determine whether an oxidation or reduction is occurring.(d) NO3 − ⟶ NO
Indicate which reactions are redox reactions.(a) Hg2(NO3)2(aq) + 2 KBr(aq) → Hg2Br2(s) + 2 KNO3(aq)(b) 4 Al(s) + 3 O2(g) → 2 Al2O3(s)(c) CaO(s) + CO2(g) → CaCO3(s)
You may want to reference(Pages 850 - 851)Section 20.1 while completing this problem.Indicate whether the following balanced equations involve oxidation-reduction.2 AgNO3(aq) + CoCl2(aq) → 2 AgCl(s) + Co(NO3)2(aq)
The accompanying photo shows the reaction between a solution of Cd(NO3)2 and one of Na2S. Is this a redox reaction?
Why must the charge balance in oxidation-reduction reactions?
You may want to reference (Pages 903 - 905)Section 20.1 while completing this problem.Indicate whether the following balanced equations involve oxidation-reduction.(a) PBr3(l) + 3 H2O (l) → H3PO3 (aq) + 3 HBr (aq)
Determine if the following is an oxidation–reduction reaction, and identify the oxidizing agent, the reducing agent, the substance being oxidized, and the substance being reduced:Cu (s) + 2 Ag+ (aq) → 2 Ag (s) + Cu2+ (aq)
Give the best definition of a redox (noncombustion) reaction.
Give an example of a redox (noncombustion) reaction.
4.46You may want to reference (Pages 138 - 144) Section 4.4 while completing this problem.Complete the sentences to explain why each statement is true or false.(b) Oxidation can occur without reduction.
Determine if the following is an oxidation–reduction reaction, and identify the oxidizing agent, the reducing agent, the substance being oxidized, and the substance being reduced:HCl (g) + NH 3 (g) → NH 4Cl (s)
Determine if the following is an oxidation–reduction reaction, and identify the oxidizing agent, the reducing agent, the substance being oxidized, and the substance being reduced:SiCl4 (l) + 2 H2O (l) → 4 HCl (aq) + SiO2 (s)
Which of the following reactions are redox reactions?a. 4 Li(s) + O2(g) → 2 Li2O(s)b. Mg(s) + Fe2+(aq) → Mg2+(aq) + Fe(s)c. Pb(NO3)2(aq) + Na2SO4(aq) → PbSO4(s) + 2 NaNO3(aq)d. HBr(aq) + KOH(aq) → H2O(l) + KBr(aq)
Determine if the following is an oxidation–reduction reaction, and identify the oxidizing agent, the reducing agent, the substance being oxidized, and the substance being reduced:SiCl4 (l) + 2 Mg (s) → 2 MgCl2 (s) + Si (s)
For the oxidation-reduction reaction equation given here, 4Al + 3O2 --> 2Al2O3 indicate how many electrons are transferred in the formation of 1 formula unit of product.
The quantity of dissolved oxygen (DO) in natural waters is an essential parameter for monitoring survival of most aquatic life. DO is affected by temperature and the amount of organic waste. An earlier method for determining DO involved a two-step process:(1) The water sample is treated with KI, O2(aq) + 4 KI (aq) + 2 H2SO4(aq) ⟶2 I2(aq) + 2 H2O(l) + 2 K2SO4(aq) (2) The I2 is titrated with sodium thiosulfate, I2(aq) + 2 Na2S2O3(aq) ⟶ Na2S4O6(aq) + 2 NaI(aq) A 50.0-mL water sample is treated with KI, and then 15.75 mL of 0.0105 M Na2S2O3 is required to reach the end point.Which substance is oxidized in step 1, and which is reduced in step 2?
Identify the atoms that are oxidized and reduced, the change in oxidation state for each, and the oxidizing and reducing agents in each of the following equations:(a) Mg(s) + NiCl2(aq) ⟶ MgCl2(aq) + Ni(s)
Identify the atoms that are oxidized and reduced, the change in oxidation state for each, and the oxidizing and reducing agents in each of the following equations:(b) PCl3(l) + Cl2(g) ⟶ PCl5(s)
Identify the atoms that are oxidized and reduced, the change in oxidation state for each, and the oxidizing and reducing agents in each of the following equations:(c) C2H4(g) + 3O2(g) ⟶ 2CO2(g) + 2H2O(g)
Identify the atoms that are oxidized and reduced, the change in oxidation state for each, and the oxidizing and reducing agents in each of the following equations:(d) Zn(s) + H2SO4(aq) ⟶ ZnSO4(aq) + H2(g)
Identify the atoms that are oxidized and reduced, the change in oxidation state for each, and the oxidizing and reducing agents in each of the following equations:(e) 2K2S2O3(s) + I2(s) ⟶ K2S4O6(s) + 2KI(s)
Identify the atoms that are oxidized and reduced, the change in oxidation state for each, and the oxidizing and reducing agents in each of the following equations:(f) 3Cu(s) + 8HNO3(aq) ⟶ 3Cu(NO3)2(aq) + 2NO(g) + 4H2O(l)
Many oxidation–reduction reactions can be balanced by inspection. Try to balance the following reaction by inspection and identify the substance reduced and the substance oxidized.Al (s) + HCl (aq) → AlCl 3 (aq) + H 2 (g)
Many oxidation–reduction reactions can be balanced by inspection. Try to balance the following reaction by inspection and identify the substance reduced and the substance oxidized.CH4 (g) + S (s) → CS 2 (l) + H2S (g)
Many oxidation–reduction reactions can be balanced by inspection. Try to balance the following reaction by inspection and identify the substance reduced and the substance oxidized.C3H8 (g) + O 2 (g) → CO 2 (g) + H2O (l)
Many oxidation–reduction reactions can be balanced by inspection. Try to balance the following reaction by inspection and identify the substance reduced and the substance oxidized.Cu (s) + Ag+ (aq) → Ag (s) + Cu 2+ (aq)
The blood alcohol (C2H5OH) level can be determined by titrating a sample of blood plasma with an acidic potassium dichromate solution, resulting in the production of Cr3+ (aq) and carbon dioxide. The reaction can be monitored because the dichromate ion (Cr2O72-) is orange in solution, and the Cr3+ ion is green. The balanced equation is16 H+ (aq) + 2 Cr2O72- (aq) + C2H5OH (aq) → 4 Cr3+ (aq) + 2 CO2 (g) + 11 H2O (l)This reaction is an oxidation–reduction reaction. What species is reduced, and what species is oxidized? How many electrons are transferred in the balanced equation above?
Use oxidation states to identify the element that is being oxidized in the following redox reaction:Sn(s) + 4HNO3(aq) → SnO2(s) + 4NO2(g) + 2H2O(g)
Use oxidation states to identify the element that is being reduced in the following redox reaction:Sn(s) + 4HNO3(aq) → SnO2(s) + 4NO2(g) + 2H2O(g)
Identify which element is oxidized and which is reduced in the following reaction:4Al(s) + 3O2(g) → 2Al2O3(s)
Identify the species that undergoes oxidation, the species that undergoes reduction, the oxidizing agent, and the reducing agent in each of the reactions of the previous problem.(a) H2O2 + Sn2+ ⟶ H2O + Sn4+ 
What is meant by the term reduction?
Identify the species that undergoes oxidation, the species that undergoes reduction, the oxidizing agent, and the reducing agent in each of the reactions of the previous problem.(b) PbO2 + Hg ⟶ Hg22+ + Pb2+ 
Identify the species that undergoes oxidation, the species that undergoes reduction, the oxidizing agent, and the reducing agent in each of the reactions of the previous problem.(c) Al + Cr2O72− ⟶ Al3+ + Cr3+
You may want to reference (Pages 850 - 851)Section 20.1 while completing this problem.Select the true statements.(a) If something is reduced, it is formally losing electrons.(b) A reducing agent gets oxidized as it reacts.(c) An oxidizing agent is needed to convert CO into CO2.
Consider the following balanced redox reaction:16H+ (aq) + 2MnO4− (aq) + 10Cl − (aq) ⟶ 2Mn 2+ (aq) + 5Cl 2 (g) + 8H2O (l)(a) Which species is being oxidized?
Consider the following balanced redox reaction:16H+ (aq) + 2MnO4− (aq) + 10Cl − (aq) ⟶ 2Mn 2+ (aq) + 5Cl 2 (g) + 8H2O (l)(b) Which species is being reduced?
Consider the following balanced redox reaction:16H+ (aq) + 2MnO4− (aq) + 10Cl − (aq) ⟶ 2Mn 2+ (aq) + 5Cl 2 (g) + 8H2O (l)(e) From which species to which does electron transfer occur?
Identify the species that was oxidized, the species that was reduced, the oxidizing agent, and the reducing agent in each of the reactions of the previous problem.(a) SO32−(aq) + Cu(OH)2(s) ⟶ SO42−(aq) + Cu(OH)(s)(b) O2(g) + Mn(OH)2(s) ⟶ MnO2(s)(c) NO3−(aq) + H2(g) ⟶ NO(g)(d) Al(s) + CrO42−(aq) ⟶ Al(OH)3(s) + Cr(OH)4−(aq)
Hydrazine (N2H4) and dinitrogen tetroxide (N2O4) form a self-igniting mixture that has been used as a rocket propellant. The reaction products are N2 and H2O.What is being oxidized, and what is being reduced? Which substance serves as the reducing agent, and which as the oxidizing agent?
Identify the species oxidized, species reduced, and the oxidizing agent and reducing agent for all the reactions in the previous problem.(a) Al(s) + Zr 4+(aq) ⟶ Al 3+(aq) + Zr(s)(b) Ag+(aq) + NO(g) ⟶ Ag(s) + NO 3−(aq)                   (acidic solution)(c) SiO32−(aq) + Mg(s) ⟶ Si(s) + Mg(OH) 2(s)              (basic solution)(d) ClO3−(aq) + MnO2(s) ⟶ Cl−(aq) + MnO4−(aq)      (basic solution)
The discovery of hafnium, element number 72, provided a controversial episode in chemistry. G. Urbain, a French chemist, claimed in 1911 to have isolated an element number 72 from a sample of rare earth (elements 58-71) compounds. However, Niels Bohr believed that hafnium was more likely to be found along with zirconium than with the rare earths. D. Coster and G. von Hevesy, working in Bohrs laboratory in Copenhagen, showed in 1922 that element 72 was present in a sample of Norwegian zircon, an ore of zirconium. (The name hafnium comes from the Latin name for Copenhagen, Hafnia) .Zirconium, hafnium’s neighbor in group 4B, can be produced as a metal by reduction of solid ZrCl4 with molten sodium metal. Is this an oxidation-reduction reaction? If yes, what is reduced and what is oxidized?
Consider the reaction:Zn(s) + Fe2+(aq) → Zn2+(aq) + Fe(s)What is being oxidized?
Consider the reaction:Zn(s) + Fe2+(aq) → Zn2+(aq) + Fe(s)What is being reduced?
In the following reaction, what is reduced? 2Al3+(aq) + 2Fe(s) → 2Al(s) + 3Fe2+(aq)a. Feb. Al3+c. Ald. Fe2+ Which of the following is the oxidizing agent? 2Al3+(aq) + 2Fe(s) → 2Al(s) + 3Fe2+ (aq)a. Feb. Al3+ c. Ald. Fe2+ 
Which element is oxidized in the following reaction?MnO4- (aq) + H2C2O4 (aq) → Mn2+ (aq) + CO2 (g)
Which element is oxidized in this reaction? ZnO + C → Zn + CO 
Find the following electron-transfer reaction Pb (s) + Br2 (I) → Pb2+(aq) - 2Br (aq) The oxidation half reaction is: The reduction half reaction is:
Type the formula for the ion that forms when a neutral atom undergoes each of the changes. Click in the answer box to open the symbol palette. Neutral F atom gains one electron to form: Neutral Mg atom loses two electrons to form:
For the following electron-transfer reaction: I2 (s) + Zn (s) → 2I (aq) + Zn2+ (aq) The oxidation half reaction is: he reduction half reaction is:
Identify the species oxidized, the species reduced, the oxidizing agent and the reducing agent in the following electron transfer reaction. 3Cl2 + 2Al → 6Cl - + 2Al3+ species oxidized:                                      species reduced:oxidizing agent:                                         reducing agent: As the reaction proceeds, electrons are transferred from ___________ to ___________
Which element is oxidized in this reaction?ZnO + C → Zn + CO
Cu2+(aq) + 2e → Cu(s) represents an oxidation half reaction.a. Trueb. False
Which of the following would be the strongest reducing agent? A. fluorine, F B. lithium,Li C. bromine, Br D. carbon, C
Which substance is the oxidizing agent in this reaction?Fe2O3 + 3CO → 2Fe + 3CO 2Express your answer as a chemical formula. 
Complete and balance the equation for this reaction in acidic solution.ZnS + NO3- → Zn2+ + S + NO i) Which element got oxidized?ii) Which element got reduced?iii) Which species was the oxidizing agent?iv) Which species was the reducing agent?
In the following reactions, identify what is oxidized and what is reduced. 2Li(s) + F2(g) → 2LiF(s)a. both Li and F are oxidizedb. both Li and F are reducedc. Li is oxidized, F is reducedd. F is oxidized, Li is reduced Cl2(g) + 2KI(aq) → 2KCl(aq) + I 2(s)a. Cl is oxidized, K is reducedb. K is oxidized, Cl is reducedc. I is oxidized, Cl is reducedd. Cl is oxidized, I is reduced Zn(s) + Cu2+(aq) → Zn2+(aq) + Cu(s)a. both Cu2+ and Zn are reducedb. both Cu2+ and Zn are oxidizedc. Cu2+ is oxidized, Zn is reducedd. Zn is oxidized, Cu2+ is reduced
Identify the oxidizing agent and the reducing agent for4Li(s) + O2(g) → 2Li2O (s)Mg(s) + Fe2+(aq) → Mg2+(aq) + Fe(s)
Which of the following is an oxidation-reduction reaction?a) Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)b) Pb(C2H3O2)2(aq) + 2NaCl(aq) → PbCl2(s) + 2NaC2H3O2(aq)c) NaI(aq) + AgNO3(aq) → AgI(s) + NaNO3(aq)d) HCl(aq) + LiOH(aq) → LiCl(aq) + H2O(l)e) All of the above are oxidation-reduction reactions.
Classify each of the following as a redox reaction or a non-redox reaction.Zn + CuCl2 → ZnCl2 + CuSO3 + H2O → H2SO4HCl + NaOH → H2O + NaCl2CO + O2 → 2CO2
Which element is oxidized in this reaction?2CuO + C → 2Cu + CO 2
Which substance is the reducing agent in this reaction?2Cr(OH)3 + 3OCl− + 4OH− → 2CrO4−2 + 3Cl−+ 5H2OExpress your answer as a chemical formula.