REDOX test practice. 2 Cr(s) + 3 Sn 2+ (aq) 2 Cr 3+ (aq) + 3 Sn(s)

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1 1. Which polyatomic ion has a charge of 3? A) chromate ion B) oxalate ion C) phosphate ion D) thiocyanate ion 2. What is the oxidation state of nitrogen in NaNO2? A) +1 B) +2 C) +3 D) What are the two oxidation states of nitrogen in the compound NH4NO3? A) 3 and 5 B) 3 and +5 C) +3 and 5 D) +3 and What is the oxidation number of chlorine in HClO4? A) +1 B) +5 C) +3 D) In a redox reaction, the total number of electrons lost is A) less than the total number of electrons gained B) greater than the total number of electrons gained C) equal to the total number of electrons gained D) equal to the total number of protons gained 6. In an oxidation-reduction reaction, reduction is defined as the A) loss of protons B) gain of protons C) loss of electrons D) gain of electrons 7. Given the reaction: Zn(s) + 2HCl(aq) ZnCl2(aq) + H2(g) The oxidation number of Zn(s) increases because it A) loses electrons B) gains electrons C) loses protons D) gains protons 8. What occurs during the reaction below? 4 HCl + MnO2 MnCl2 + 2 H2O + Cl2 A) The manganese is reduced and its oxidation number changes from +4 to +2. B) The manganese is oxidized and its oxidation number changes from +4 to +2. C) The manganese is reduced and its oxidation number changes from +2 to +4. D) The manganese is oxidized and its oxidation number changes from +2 to Which half-reaction correctly represents oxidation? A) Fe(s) Fe 2+ (aq) + 2e B) Fe 2+ (aq) Fe(s) + 2e C) Fe(s) + 2e Fe 2+ (aq) D) Fe 2+ (aq) + 2e Fe(s) 10. Given the redox reaction: 2 Cr(s) + 3 Sn 2+ (aq) 2 Cr 3+ (aq) + 3 Sn(s) Which species serves as the reducing agent? A) Cr B) Sn 2+ C) Cr 3+ D) Sn 11. Given the electrochemical cell reaction: Zn(s) + Ni 2+ (aq) Zn 2+ (aq) + Ni(s) Which species is the reducing agent? A) Zn B) Ni 2+ C) Zn 2+ D) Ni 12. Given the balanced equation representing a redox reaction: 2Al + 3Cu 2+ 2Al Cu Which statement is true about this reaction? A) Each Al loses 2e and each Cu 2+ gains 3e. B) Each Al loses 3e and each Cu 2+ gains 2e. C) Each Al 3+ gains 2e and each Cu loses 3e. D) Each Al 3+ gains 3e and each Cu loses 2e. 13. Given the reaction for the corrosion of aluminum: 4 Al + 3 O2 2 Al2O3 Which half-reaction correctly represents the oxidation that occurs? A) Al + 3e Al 3+ B) Al Al e C) O2+ 4e 2 O 2 D) O2 2 O 2 + 4e 14. Given the equation: 2 Al + 3 Cu 2+ 2 Al Cu The reduction half-reaction is A) Al Al e - B) Cu e - Cu C) Al + 3e - Al 3+ D) Cu 2+ Cu + 2e -

2 15. Given the reaction: Cu(s) + 4 HNO3(aq) Cu(NO3)2(aq) + 2 NO2(g) + 2 H2O( ) As the reaction occurs, what happens to copper? A) It undergoes reduction and its oxidation number decreases. B) It undergoes reduction and its oxidation number increases. C) It undergoes oxidation and its oxidation number decreases. D) It undergoes oxidation and its oxidation, number increases. 16. Given the reaction: 2 Al 0 (s) + 3 Ni 2+ (aq) 2 Al 3+ (aq) + 3 Ni 0 (s) What is the total number of moles of electrons lost by 2 moles of Al 0 (s)? A) 6 B) 2 C) 3 D) Given the reaction: Mg(s) + Cl2(g) MgCl2(s) Which half-reaction correctly represents the reduction that occurs? A) Mg(s) + 2e Mg 2+ B) Cl2(g) + 2e 2 Cl C) Mg 2+ Mg(s) + 2e D) 2 Cl Cl2 + 2e 18. In which reaction are electrons transferred from one reactant to another reactant? A) 2Ca(s) + O2 (g) 2CaO(s) B) AgNO3 (aq) + KCl(aq) AgCl(s) + KNO3 (aq) C) HCl(aq) + NaOH(aq) NaCl(aq) + H2O( ) D) H3O + (aq) + OH (aq) 2H2O( ) 19. Which equation represents an oxidation-reduction reaction? A) HCl + KOH KCl + H2O B) 4 HCl + MnO2 MnCl2 + 2 H2O + Cl2 C) 2 HCl + CaCO3 CaCl2 + H2O + CO2 D) 2 HCl + FeS FeCl2 + H2S 20. Referring to Reference Table J, which reaction will not occur under standard conditions? A) Sn(s) + 2 HCl(aq) SnCl2(ag) + H2(g) B) Cu(s) + 2 HCl(aq) CuCl2(aq) + H2(g) C) Ba(s) + 2 HCl(aq) BaCl2(aq) + H2(g) D) Mg(s) + 2 HCl(aq) MgCl2(aq) + H2(g) 21. According to Reference Table J, which redox reaction occurs spontaneously? A) Cu(s) + 2 H + Cu 2+ + H2(g) B) Mg(s) + 2 H + Mg 2+ + H2(g) C) 2 Ag(s) + 2 H + 2 Ag + H2(g) D) 2 Ag(s) + 2 H + 2 Ag 2+ + H2(g) 22. Which half-reaction for the reduction of Al 3+ to Al is correctly balanced? A) Al e Al B) Al e 3 Al C) Al 3+ Al + 3e D) Al 3+ 3 Al + 3e 23. In the reaction Ni + 2 Ag + Ni Ag, what is the total number of moles of electrons lost by 1 mole of Ni? A) 1 B) 2 C) 0.5 D) Which half-reaction shows both the conservation of mass and the conservation of charge? A) Cl2 + 2e 2 Cl B) Cl2 Cl + 2e C) 2 Br + 2e Br2 D) Br Br2 + 2e

3 25. Iron corrodes according to the equation 4 Fe + 3 O2 2 Fe2O3. This redox process occurs because A) iron loses electrons and is oxidized B) iron gains electrons and is reduced C) oxygen loses electrons and is reduced D) oxygen gains electrons and is oxidized 26. The chemical reaction that causes corrosion of metals in contact with water and oxygen is A) a substitution reaction B) an addition reaction C) a neutralization and ionization reaction D) a reduction and oxidation reaction 27. Which redox equation is correctly balanced? A) Cr(s) + 3 Fe 2+ (aq) 2 Cr 3+ (aq) + Fe(s) B) Pb(s) + 2 H + (aq) Pb 2+ (aq) + H2(g) C) Pb(s) + Ag + (aq) Pb 2+ (aq) + Ag(s) D) Zn(s) + Br2(aq) Zn 2+ (aq) + Br (aq) 28. Which equation shows conservation of both mass and charge? A) Cl2 + Br Cl + Br2 B) Cu + 2 Ag + Cu 2+ + Ag C) Zn + Cr 3+ Zn 2+ + Cr D) Ni + Pb 2+ Ni 2+ + Pb 29. During the operation of a voltaic cell, the cell produces A) electrical energy spontaneously B) chemical energy spontaneously C) electrical energy nonspontaneously D) chemical energy nonspontaneously 30. A voltaic cell spontaneously converts chemical energy to A) electrical energy B) geothermal energy C) mechanical energy D) nuclear energy 31. A battery consists of which type of cells? A) electrolytic B) electrochemical C) electroplating D) electromagnetic 32. Base your answer to the following question on the equation and diagram below represent an electrochemical cell at 298 K and 1 atmosphere. Which species is oxidized when the switch is closed? A) Mg(s) B) Mg 2+ (aq) C) Ag(s) D) Ag + (aq)

4 33. Base your answer to the following question on the diagram of the chemical cell at 298 K and on the equation below. 37. Which term identifies the half-reaction that occurs at the anode of an operating electrochemical cell? A) oxidation B) reduction C) neutralization D) transmutation 38. Which statement describes electrolysis? A) Chemical energy is used to produce an electrical change. B) Chemical energy is used to produce a thermal change. C) Electrical energy is used to produce a chemical change. D) Thermal energy is used to produce a chemical change. 39. The diagram below shows a key being plated with copper in an electrolytic cell In the given reaction, the Ag + ions A) gain electrons B) lose electrons C) gain protons D) lose protons 34. What occurs during discharge in the lead-acid battery reaction below? Pb + PbO2 + 2 H2SO4 «2 PbSO4 + 2 H2O A) Both Pb and Pb 4+ undergo oxidation. B) Both Pb and Pb 4+ undergo reduction. C) Pb is oxidized and Pb 4+ is reduced. D) Neither the Pb nor the Pb 4+ is oxidized or reduced. 35. Reduction occurs at the cathode in A) electrolytic cells, only B) voltaic cells, only C) both electrolytic cells and voltaic cells D) neither electrolytic cells nor voltaic cells 36. Which statement is true about oxidation and reduction in an electrochemical cell? A) Both occur at the anode. B) Both occur at the cathode. C) Oxidation occurs at the anode and reduction occurs at the cathode. D) Oxidation occurs at the cathode and reduction occurs at the anode. Given the reduction reaction for this cell: Cu 2+ (aq) + 2e - Cu(s) This reduction occurs at A) A, which is the anode B) A, which is the cathode C) B, which is the anode D) B, which is the cathode 40. In an electrolytic cell, the positive electrode is the A) anode, where oxidation occurs B) anode, where reduction occurs C) cathode, where oxidation occurs D) cathode, where reduction occurs

5 Answer Key REDOX 2016 Test Practice 1. C 2. C 3. B 4. D 5. C 6. D 7. A 8. A 9. A 10. A 11. A 12. B 13. B 14. B 15. D 16. A 17. B 18. A 19. B 20. B 21. B 22. A 23. B 24. A 25. A 26. D 27. B 28. D 29. A 30. A 31. B 32. A 33. A 34. C 35. C 36. C 37. A 38. C 39. B 40. A