Name: Regents Chemistry Date:

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1 Name: Date: 1. The reaction CuO + CO CO 2 + Cu is an example of (A) reduction, only (B) oxidation, only (C) both oxidation and reduction (D) neither oxidation nor reduction 6. In which compound does chlorine have an oxidation number of +5? (A) HClO (C) HClO 3 (B) HClO 2 (D) HClO 4 7. Which species is produced when a hydrogen atom is oxidized? (A) (C) 2. Given the reaction: F 2 (g) + 2 Br (aq) Br 2 ( ) + 2 F (aq) (B) (D) Which species is reduced? (A) F 2 (g) (B) Br (aq) (C) Br 2 ( ) (D) F (aq) 3. Which equation represents a redox reaction? (A) SO 2 + H 2 O H 2 SO 3 (B) SO H + + H 2 SO 3 (C) O H 2 2 H 2 O (D) OH + H + H 2 O 4. Given the lead-acid battery reaction: Which species is oxidized during battery discharge? (A) Pb 2 (C) SO 4 (B) PbO 2 (D) H 2 O 5. Given the balanced equation representing a reaction occurring in an electrolytic cell: 2NaCl( ) 2Na( ) + Cl 2 (g) Where is Na( ) produced in the cell? (A) at the anode, where oxidation occurs (B) at the anode, where reduction occurs (C) at the cathode, where oxidation occurs (D) at the cathode, where reduction occurs 8. Which component of an electrochemical cell is correctly paired with its function? (A) external conductor allows the solutions to mix (B) external conductor permits the migration of ions (C) salt bridge allows the solutions to mix (D) salt bridge permits the migration of ions 9. The transfer of which particle is required for a redox reaction to occur? (A) electron (C) neutron (B) ion (D) proton 10. According to Reference Table J, which will reduce Mg 2+ to Mg(s)? (A) Fe(s) (C) Pb(s) (B) Ba(s) (D) Ag(s) 11. In which substance does chlorine have an oxidation number of +1? (A) Cl 2 (C) HClO (B) HCl (D) HClO Given the equation for the discharge of a lead acid battery: Pb + PbO H 2 SO 4 2 PbSO H 2 O Which substance is oxidized? (A) Pb (C) H 2 SO 4 (B) PbO 2 (D) PbSO 4

2 13. Which is a redox reaction? (A) H + + Cl HCl (B) NaOH + HCl NaCl + H 2 O (C) Fe + 2 HCl FeCl 2 + H 2 (D) MgO + H 2 SO 4 MgSO 4 + H 2 O 14. Which half-reaction shows both the conservation of mass and the conservation of charge? (A) Cl 2 + 2e 2 Cl (C) 2 Br + 2e Br 2 (B) Cl 2 Cl + 2e (D) Br Br 2 + 2e 15. Given the overall cell reaction: Zn(s) + 2 Ag + (aq) Zn 2+ (aq) + 2 Ag(s) Which will occur as the cell operates? (A) The amount of Zn(s) will increase. (B) The amount of Ag(s) will decrease. (C) The concentration of Zn +2 (aq) will increase. (D) The concentration of Ag + (aq) will increase. 16. Given the equation: 2 Al + 3 Cu 2+ 2 Al Cu 18. The overall reaction in a electrochemical cell is Zn(s) + Cu 2+ (aq) Zn 2+ (aq) + Cu(s). As the reaction in this cell takes place, the (A) mass of the Zn(s) electrode decreases (B) mass of the Cu(s) electrode decreases (C) Cu 2+ (aq) concentration remains the same (D) Zn 2+ (aq) concentration remains the same 19. The diagram below represents a chemical cell at 298 K. The reduction half-reaction is (A) Al Al e - (C) Al + 3e - Al 3+ (B) Cu e - Cu (D) Cu 2+ Cu + 2e Given the reaction: 2 H 2 O + electricity 2 H 2 + O 2 In which type of cell would this reaction most likely occur? (A) a chemical cell, because it is exothermic (B) an electrolytic cell, because it is exothermic (C) a chemical cell, because it is endothermic (D) an electrolytic cell, because it is endothermic When the switch is closed, electrons flow from (A) Al(s) to Ni(s) (C) Al 3+ (aq) to Ni 2+ (aq) (B) Ni(s) to Al(s) (D) Ni 2+ (aq) to Al 3+ (aq) 20. When an equation is correctly balanced, it must show conservation of (A) charge but not of mass (B) mass but not of charge (C) both charge and mass (D) neither charge nor mass 21. Which metal reacts spontaneously with a solution containing zinc ions? (A) magnesium (C) copper (B) nickel (D) silver 22. Which half-reaction equation represents the reduction of a potassium ion? (A) K + + e K (C) K + K + e (B) K + e K + (D) K K + + e

3 23. In which substance does sulfur have an oxidation state of +4? (A) H 2 S (C) SO 3 (B) S (D) SO How many moles of electrons would be required to completely reduce 1.5 moles of Al 3+ to Al? (A) 0.50 (C) 3.0 (B) 1.5 (D) A redox reaction always involves (A) a change in oxidation number (B) a change of phase (C) the transfer of protons (D) the formation of ions 30. Given the redox reaction: 25. Which half-reaction correctly represents oxidation? (A) F 2 2 F + 2e (C) H 2 2 H + + 2e (B) F 2 + 2e 2 F (D) H 2 + 2e 2 H Given the reaction: Ca(s) + Cu 2+ (aq) Ca 2+ (aq) + Cu(s) What is the correct reduction half-reaction? (A) Cu 2+ (aq) + 2e Cu(s) (B) Cu 2+ (aq) Cu(s) + 2e (C) Cu(s) + 2e Cu 2+ (aq) (D) Cu(s) Cu 2+ (aq) + 2e Which species is oxidized during discharge? (A) Cd (C) Ni(OH) 3 (B) Cd 2+ (D) Ni(OH) Base your answer to the following question on the diagram of the chemical cell shown below. The reaction occurs at 1 atmosphere and 298 K. 27. Based on the Activity Series, which ion will react spontaneously with Co(s)? (A) Zn 2+ (C) Li + (B) Al 3+ (D) Ag Given the reaction for the nickel-cadmium battery: 2 NiO(OH) 3 + Cd + 2 H 2 O 2 Ni(OH) 2 + Cd(OH) 2 Which species is oxidized during the discharge of the battery? (A) Ni 3+ (C) Cd (B) Ni 2+ (D) Cd 2+ When the switch is closed, what occurs? (A) Pb is oxidized and electrons flow to the Zn (B) Pb is reduced and electrons flow to the Zn (C) Zn is oxidized and electrons flow to the Pb (D) Zn is reduced and electrons flow to the Pb

4 32. An electrolytic cell is different from an electrochemical cell because in an electrolytic cell (A) a redox reaction occurs (B) a spontaneous reaction occurs (C) an electric current is produced (D) an electric current causes a chemical reaction

5 Answer Key [New Exam] 1. C 2. A 3. C 4. A 5. D 6. C 27. D 28. C 29. A 30. A 31. C 32. D 7. D 8. D 9. A 10. B 11. C 12. A 13. C 14. A 15. C 16. B 17. D 18. A 19. A 20. C 21. A 22. A 23. D 24. D 25. C 26. A