Chemistry 12 Unit 4 Test Modified True/FalseIndicate whether the sentence or statement is true or false. If false, change the identified word or phrase to make the sentence or statement true. ____ 1. Oxidation processes always result in a decrease in the oxidation number of a species. _________________________ ____ 2. Silver is a stronger reducing agent than aluminum. _________________________ ____ 3. An oxidizing agent is an electron donor. ______________________________ ____ 4. When an atom loses an electron during a redox reaction, its oxidation number increases. _________________________ ____ 5. When the oxidation number of an atom decreases during a redox reaction, it is acting as a reducing agent. _________________________ ____ 6. The oxidation number of a monatomic ion is the same as the charge on the ion. _________________________ ____ 7. In all redox reactions, electrons are transferred from an oxidizing agent to a reducing agent. ________________________________________ ____ 8. In redox reactions, metals always behave as reducing agents. _________________________ ____ 9. In a redox table, the strongest oxidizing agent is at the top left side of the table. _________________________ ____ 10. In a redox table, the strongest reducing agent is at the bottom left side of the table. ______________________________ ____ 11. The strongest oxidizing agent present in an electric cell always undergoes a reduction at the cathode. _________________________ ____ 12. The electrolytic cell potential, , is always positive. _________________________ ____ 13. The anode of an electrolytic cell is the positive electrode. _________________________ ____ 14. Electrolysis is the process by which electrical energy is passed through a molten ionic compound to cause a nonspontaneous reaction to occur. _________________________ ____ 15. To produce one mole of copper by the electrolysis of requires the same amount of electric charge as the production of one mole of silver from . ____________________________________ ____ 16. The electrolysis of water produces twice as much volume of hydrogen gas at the cathode as oxygen gas at the anode. _________________________ ____ 17. The electrolysis of water using inert electrodes produces hydrogen gas at the anode and oxygen gas at the cathode. ___________________________________________________ ____ 18. Electrolysis is used in electroplating, and in refining of metals. _________________________ ____ 19. When water is electrolyzed, the products, and , possess less potential energy than the reactant, . ________________________________ ____ 20. In a silver-plating cell, the object to be plated is made the anode. _________________________ Multiple ChoiceIdentify the letter of the choice that best completes the statement or answers the question. ____ 21. In which of the following compounds does nitrogen have the highest oxidation number?a. d.b. e.c.____ 22. Experiments were performed with four strips of metals , , , and , and their corresponding nitrate solutions , , , and . The following observations were obtained:Ano reaction no reaction no reaction no reactionprecipitate no reaction precipitate precipitateprecipitate no reaction no reaction no reactionprecipitate no reaction precipitate no reactionWhich of the following is the correct list of the metal ions in order of decreasing strength as oxidizing agents (strongest oxidizing agent first)?a. d.b. e.c.____ 23. Which element is oxidized in the following reaction? a. in d. inb. in e.c. in____ 24. Given the following unbalanced oxidation-reduction equation: In the balanced equation, the coefficient of isa. 2 d. 5b. 3 e. 6c. 4 ____ 25. Consider the above cell at 25? C. In the left half-cell, a lead electrode is in contact with 0.10 mol/L and in the right half-cell, a copper electrode is in contact with 0.20 mol/L . The standard reduction potentials are as follows: Which of the following statements about this cell is false?a. ions migrate into the left half-cell through the salt bridgeb. electrons flow from the copper electrode to the lead electrodec. the cell is not at standard conditionsd. ions migrate into the right half-cell through the salt bridgee. reduction occurs at the copper electrode____ 26. Given The for the reaction isa. +0.18 V d. +0.37 Vb. 0.18 V e. 0.37 Vc. 0.67 V ____ 27. The concentration of both solutions in the cell below are 1.0 mol/L. Given the following standard reduction potentials: Which of the following statements are true?I. oxidation occurs at the Ag electrode.II. the Ag electrode is the negative terminal of the cell.III. electrons flow from the Ni electrode to the Ag electrode through the external circuit.IV. the Ni electrode is the anode.a. I and II d. III and IVb. I and III e. II and IVc. II and III____ 28. Given the standard reduction potentials for the following half-reactions: What is the standard reduction potential for the reaction?a. +1.16 V d. +0.58 Vb. +0.10 V e. 0.58 Vc. 0.10 V____ 29. Given the following information: What is the minimum voltage necessary for the electrolysis of a 1.0 mol/L solution of sodium sulfate using inert electrodes?a. 4.72 V d. 2.83 Vb. 3.53 V e. 1.23 Vc. 3.12 V____ 30. In an electrolytic cell using inert electrodes, a current of 4.00 A is passed through a molten binary salt with the formula for 20.0 minutes. 1.15 g of metal is produced at the cathode. What is the metal ?a. d.b. e.c.CompletionComplete each sentence or statement. 31. A reaction in which electrons are gained is a(n) ____________________ reaction. 32. If the algebraic sum of the for two half-cells is ____________________, the reaction will proceed spontaneously. 33. Negatively charged ions are called ____________________ and migrate toward the ____________________ electrode of the electrochemical cell. 34. In an electrochemical cell oxidation occurs at the ____________________. 35. When an atom gains an electron, it is acting as a(n) ____________________ agent. 36. When an atom gains an electron during a redox reaction, its oxidation number ____________________. 37. Downs cell is used for the production of ____________________ metal. 38. The quantity of charge transferred by a current of 1.0 A during a time of 1.0 s is called a(n) ____________________. 39. One faraday is equal to one ____________________ of electrons. 40. In the electrolysis of copper sulfate solution, ____________________ are reduced at the cathode. Matching Match each of the following terms with its appropriate description.a. electrode e. primary cellb. electrolyte f. electric cellc. secondary cell g. fuel celld. battery h. corrosion____ 41. an electric cell that cannot be recharged ____ 42. an electric cell that can be recharged ____ 43. the spontaneous oxidation of a metal by substances in the environment ____ 44. a group of two or more electric cell connected in series ____ 45. an aqueous electrical conductor Short Answer 46. List four factors that accelerate the corrosion of iron. 47. What process occurs at the cathode of an electrolytic cell while the cell is operating? 48. Predict the cathode and anode reactions during the electrolysis of 1 mol/L nickel iodide solution, , using carbon electrodes. 49. Predict the net cell reaction during the electrolysis of 1 mol/L nickel iodide solution, , using carbon electrodes. 50. Predict the net cell reaction during the electrolysis of 1 mol/L sodium hydroxide solution, , using inert electrodes.Chemistry 12 Unit 3 Test Modified True/FalseIndicate whether the sentence or statement is true or false. If false, change the identified word or phrase to make the sentence or statement true. ____ 1. When a precipitate forms at the bottom of a container after 2 unsaturated solutions are mixed, the solid precipitate is always in equilibrium with its liberated ions in solution. _________________________ ____ 2. Ksp values are temperature dependent. _________________________ ____ 3. More potassium bromide can dissolve in distilled water than in a solution of potassium chloride. _________________________ ____ 4. The formula for silver acetate is AgC3H5O2. _________________________ ____ 5. The Ksp equilibrium expression for lead(II) chloride is Pb2Cl(s) <====> 2Pb2+(aq) + Cl1-(aq). _________________________ ____ 6. For the gaseous equilibrium shown, 3A + B <====> C + 2D, some C is added to the system. The quantity of D will rise. _________________________ ____ 7. For the gaseous equilibrium shown, 2A + 3B <====> C + 2D + heat.If the temperature of the system is decreased, the quantity of B will increase 3/2 as much as the quantity of A. ______________________________ ____ 8. For the gaseous equilibrium shown, 3A + B <====> 4C + D + heat.If some B is removed from the system, the quantity of C will decrease 4???s as much as the quantity of D decreases. _________________________ ____ 9. For the gaseous equilibrium shown, 2A + 3B <====> 4C + D + heat.If some B is added to the system, the quantity of C will decrease 4???s as much as the quantity of D decreases. ______________________________ ____ 10. In a saturated solution of cobalt(II) hydroxide, the quantity of cobalt(II) ion is double the quantity of hydroxide ion. __________________________________________________ ____ 11. A system at equilibrium means the concentration of reactants is equal to the concentration of products. _______________________________________________________ ____ 12. The pH scale ranges from 0 to 14. ___________________________________ ____ 13. A concentrated weak acid cannot have a lower pH than a dilute strong acid. _________________________ ____ 14. A concentrated weak base can have a lower pOH than a dilute strong base. _________________________ ____ 15. 1.0 mol/L solutions of weak bases will have a higher pH than 1.0 mol/L solutions of strong bases. _________________________ ____ 16. Conjugate acid base partners differ by a single proton. _________________________ ____ 17. Salts containing anion which is not found in a strong acid can act like weak bases. _________________________ ____ 18. Salts contain cations found in the alkali metal family cannot act like weak acids. _________________________ ____ 19. If the pH of an aquatic solution at 95oC is 4.5 the pOH must be 9.5. ___________________________________ ____ 20. When HCl is titrated with NaOH the endpoint is indicated when an excess of HCl turns the indicator a different colour. _________________________ Multiple ChoiceIdentify the letter of the choice that best completes the statement or answers the question. ____ 21. In a saturated solution of aluminum hydroxide, the concentration of aluminum ion is 2.4 ? 10-8 mol/L. The Ksp of aluminum hydroxide would be which of the following?a. 1.7 ? 10-15 d. 9.0 ? 10-30b. 4.2 ? 10-23 e. none of the abovec. 1.0 ? 10-30____ 22. For the equilibrium system below, which of the following would result in an increase in the quantity of Cl2(g)?PCl3(g) + Cl2(g) <=====> PCl5(g) + 45 kJa. adding some PCl3(g) d. increasing the volume of the containerb. removing some PCl5(g) e. injecting some He gasc. decreasing temperature____ 23. The Ksp for a substance A2B is 1.2 ? 10-12. The [B] must be which of the following?a. 4.0 ? 10-11 d. 1.3 ? 10-4b. 3.6 ? 10-12 e. 2.6 ? 10-4c. 6.7 ? 10-5____ 24. The Ksp for a substance A2B is 1.2 ? 10-12. The [A] must be which of the following?a. 4.0 ? 10-11 d. 1.3 ? 10-4b. 3.6 ? 10-12 e. none of the abovec. 6.7 ? 10-5____ 25. The Ksp for a substance AB3 is 7.8 ? 10-10. The [A] is which of the following?a. 7.0 ? 10-3 d. 1.6 ? 10-2b. 5.3 ? 10-3 e. 2.9 ? 10-11c. 2.3 ? 10-3____ 26. Which of the following salts act like acids when applied to the soil?a. BeCl2 d. NaFb. KF e. KClc. FeI3____ 27. Which of the following salts act like bases when applied to the soil?a. NaHSO4 d. LiNO3b. KNO2 e. KClO4c. CaCl2____ 28. When water is heated to its boiling point the system has which of the following?a. increased entropy and decreased enthalpyb. decreased entropy and increased enthalpyc. increased both entropy and enthalpyd. decreased both entropy and enthalpye. none of the above____ 29. When water is cooled to its freezing point the system has which of the following?a. increased entropy and decreased enthalpyb. decreased entropy and increased enthalpyc. increased both entropy and enthalpyd. decreased both entropy and enthalpye. none of the above____ 30. A solution of nitrous acid has a pH of 2.45. The [H1+] in mol/L and pOH must be respectivelya. 3.5 ? 10-3, 11.55 d. 2.8 ? 10-12, 12b. 3.6 ? 10-3, 11.55 e. 3.8 ? 10-3, 12.55c. 2.8 ? 10-12, 11.6CompletionComplete each sentence or statement. 31. If solutions of sodium phosphate and zinc bromide were mixed and a precipitate formed, the precipitate would be _________________________. 32. 4NO(g) ? 2N2O(g) + O2(g); during this chemical change the algebraic sign for the entropy change is predicted to be ____________________. 33. A buffer can contain a weak base and a salt containing _____________________________________________. 34. A 1.5 mol/L solution of HCl(aq) has a pH of ____________________. 35. The pOH of a basic solution is always ____________________. Matching Here is a list of weak acids. Match to its conjugate base partner below. If no match exists indicate by writing none.a. H2O d. HPO42-b. HSO41- e. H2CO3c. HC2H3O2 f. H2C6H6O6____ 36. C2H3O21- ____ 37. SO42- ____ 38. HC6H6O61- ____ 39. OH1- ____ 40. HCO31- Short Answer 41. Consider the equilibrium below:If 1.5 mol of PCl5 was placed in a 1.0 L container and allowed to reach equilibrium, what would the value of Ke be if at equilibrium [PCl5] = 1.2 mol/L?PCl3(g) + Cl2(g) <=====> PCl5(g) 42. Consider the equilibrium below:If 1.2 mol of H2 and 1.2 mol of O2 was placed in a 1.0 L container and allowed to reach equilibrium, what would the value of Ke be if at equilibrium [HI] = 0.40 mol/L?H2(g) + I2(g) <=====> 2HI(g) 43. Consider the equilibrium below:If 1.6 mol of HI was placed in a 1.0 L container and allowed to reach equilibrium, what would the equilibrium concentrations be for H2(g), I2(g) and HI(g) if the Ke = 36?H2(g) + I2(g) <=====> 2HI(g) 44. If the pH of an acid solution at 25oC is 6.18, what is the pOH; and the [H1+], [OH1-] in mol/L? 45. If the [H1+] of a solution at 25oC is 4.9 ? 10-4 mol/L, calculate the [OH1-] in mol/L, the pH and the pOH. Problem 46. If 12 L of a saturated solution of PbSO4 is found to contain 0.46 g of PbSO4, what is the Ksp of PbSO4 47. What mass of Mg(OH)2 would be found in 7.6 ? 102 mL of a saturated solution of Mg(OH)2 if the Ksp of Mg(OH)2 is 9.0 ? 10-12? 48. If 145 mL of a 0.0078 mol/L solution of CuNO3 was mixed with 195 mL of a 1.48 ? 10-3 mol/L solution of KI, would a precipitate form? Calculate the ion product for the potential precipitate. The Ksp of CuI is 1 ? 10-12. 49. What is the pH of a 3.4 mol/L solution of KOH? 50. 24 mL of 0.39 mol/L acetic acid is titrated with a standardized 0.33 mol/L KOH solution. Calculate the pH of the solution after 17 mL of the KOH solution has been added. Assume the Ka of acetic acid is 1.8 ? 10-5.