Summary Lester B Pearson Catholic High SchoolCHEMISTRY 10Merged Redox Worksheets Jan 2015

Electrochemistry (Redox) Unit Outline Date Content Worksheets Textbook Questions February 5 Quiz – Chem 20 Review Redox Definitions February 6 Oxidation #’s Pages 1 - 6 Pg. 585 # 1-5 Pg. 586 #13.B Pg. 588 #6-9 February 9 OA’s/RA’s Half reactions Pages 7 - 8 Pages 9 - 10 Pg. 599 #2 Pg. 654#8,9 Prep Lab 13.2 (Pg. 569) February 10 Lab 13.2 Ranking & Spontaneity Pg. 527 13.A 573 #11- 18, 20-21, 23-24 February 11 Predicting Redox Reactions Page 11 Pg. 571 # 2-10 Pg. 579 # 26, 28-30 February 17 Balancing by Oxidation #’s Pages 12 - 13 Pg. 593 # 12, 15 Pg. 595 # 4 -8, 10, 12 February 18 Quiz – Up to and including predicting Prep Lab 13.4 Prep Lab 13.4 (Pg. 599) February 19 Balancing with half reactions Pages 14 - 15 Pg. 581 # 31, 33 February 20 Work period and SLP’s February 23 Quiz – Balancing Intro. Redox Stoich. Page 16 February 24 Lab 13.4 – Redox Stoichiometry February 25 Redox Stoich. Page 16 Pg. 598 Lab Ex. 13.C, # 3, 5 Pg. 599 Lab Ex. 13.D Pg. 600 # 4 - 6 February 26 Voltaic Cells Pages 17 - 19 Pg 626 # #3 - 8 February 27 Lab 14.3 – Cell Potential Lab Page 20 Lab 14.3 (Pg. 660) Pg. 631 #11 Pg. 633 Lab Ex. 14.A, # 12 - 13 March 2 Electrolytic Cells Page 23 Questions 1 – 3, 12 - 14 Pg. 645 # 7 - 15 March 3 Corrosion Page 23 Questions 3 - 11 Pg. 637 # 17 – 24 Pg. 651 March 4 Quiz – Cells and Corrosion March 5 Electroplating Cell Stoich. March 6 Cell Stoich. Page 23 Questions 4 - 14 Pg. 654 # 5-7 Pg. 657 # 1 - 12 March 9 Redox Review Pages 24 - 30 Pg. 666 # 1-20, 23, 26, 30-31, 33, 35, 37, 39, 45, 46, 48, 51 March 10 Redox Unit Exam1 Assigning Oxidation Numbers 1. Assign oxidation numbers to chlorine in each of the following chemicals. HCl(aq), Cl2(g), NaClO(s), Cl−(aq), HClO3(aq), ClO3−(aq), KClO2(s), ClO2(g), HClO4(aq) 2. Assign oxidation numbers to manganese in each of the following chemicals. MnO2(s), KMnO4(s), Mn(s), MnO42−(aq), MnCl2(s), Mn2O7(s), Mn2+(aq) For the following reaction equations, use oxidation numbers to identify the oxidation (the atom oxidized) and the reduction (the atom reduced). 3. AsO33−(aq) + IO3–(aq) → AsO43−(aq) + I−(aq) 4. CuO(s) + NH3(g) → N2(g) + H2O(l) + Cu(s) 5. MnO4−(aq) + H2Se(g) + H+(aq) → Se(s) + Mn2+(aq) + H2O(l) 6. PbO2(s) + Pb(s) + H2SO4(aq) → PbSO4(s) + H2O(l) 7. Cl2(g) + OH–(aq) → ClO3–(aq) + Cl–(aq) + H2O(l)2 Solutions for Oxidation Numbers 1. Assign oxidation numbers to chlorine in each of the following chemicals. –1 0 +1 –1 +5 HCl(aq), Cl2(g), NaClO(s), Cl–(aq), HClO3(aq), +5 +3 +4 +7 ClO3–(aq), KClO2(s), ClO2(g), HClO4(aq) 2. Assign oxidation numbers to manganese in each of the following chemicals. +4 +7 0 +6 +2 MnO2(s), KMnO4(s), Mn(s), MnO42–(aq), MnCl2(s), +7 +2 Mn2O7(s), Mn2+(aq) For the following reaction equations, use oxidation numbers to identify the oxidation (the atom oxidized) and the reduction (the atom reduced). +3 − +5 −2 +5 −2 −1 3. AsO33–(aq) + IO3–(aq) → AsO43–(aq) + I–(aq) +3 +5 +5 −1 As is oxidized; I is reduced +2 −2 −3 +1 0 +1 −2 0 4. CuO(s) + NH3(g) → N2(g) + H2O(l) + Cu(s) +2 −3 0 0 N is oxidized; Cu is reduced +7 −2 +1 −2 +1 0 +2 +1 −2 5. MnO4–(aq) + H2Se(g) + H+(aq) → Se(s) + Mn2+(aq) + H2O(l) +7 −2 0 +2 Se is oxidized; Mn is reduced +4 −2 0 +1 + 6 −2 +2 +6 −2 +1 −2 6. PbO2(s) + Pb(s) + H2SO4(aq) → PbSO4(s) + H2O(l) +4 0 +2 Pb is oxidized; Pb is reduced (Note that the lead(IV) ions in PbO2 and the lead atoms in the metal element are both converted into lead(II) ions in the course of this reaction, which represents a car battery discharging.) 0 –2 +1 +5 –2 –1 +1 –2 7. Cl2(g) + OH–(aq) → ClO3–(aq) + Cl–(aq) + H2O(l) 0 +5 –1 Cl is oxidized; Cl is reduced (Note that some of the chlorine gas atoms are oxidized while others are reduced.)3 Chemistry 30 – Oxidation Number Worksheet 1. Determine the oxidation number of sulfur in the following compounds: a. H2S b. S8 c. SCl2 d. Na2SO3 e. SO42- 2. Determine the oxidation state of the underlined element. a. P2O5 b. NaH c. HAsO42- d. SnBr4 e. BaO2 f. Fe2O3 g. SnCl4 h. K2O2 i. NO2- j. UO22+ k. CuCl42- l. Hg2Cl2 m. Mg2P2O74 3. Determine the oxidation states for each element in the compound. a. sodium nitrate ________________________ b. ammonia ____________________________ c. zinc oxide ____________________________ d. water _______________________________ e. calcium hydride _______________________ f. carbon dioxide ________________________ g. nitrogen _____________________________ h. sodium sulfate ________________________ i. aluminum hydroxide ___________________ j. magnesium phosphate _________________ 4. In each of the following reactions, determine what element was oxidized and what element was reduced. a. Ca + H2O
CaO + H2 i. element oxidized _________________ ii. element reduced _________________ b. 2 H2 + O2
2 H2O i. element oxidized __________________ ii. element reduced __________________5 1. Determine the oxidation number of sulfur in the following compounds: a. H2S H = +1 S = -2 b. S8 S = 0 c. SCl2 S = +2 Cl = -1 d. Na2SO3 Na = +1 S = +4 O = -2 e. SO42- S = +6 O = -2 2. Determine the oxidation state of the underlined element. a. P2O5 P = +5 b. NaH H = -1 (hydride) c. HAsO42- As = +5 d. SnBr4 Sn = +4 e. BaO2 O = -1 (peroxide) f. Fe2O3 Fe = +3 g. SnCl4 Sn = +4 h. K2O2 O = -1 (peroxide) i. NO2- N = +3 j. UO22+ U = +6 k. CuCl42- Cu = +2 l. Hg2Cl2 Hg = +1 m. Mg2P2O7 P = +66 3. Determine the oxidation states for each element in the compound. a. sodium nitrate Na = +1 N = +5 O = -2 b. ammonia N = -3 H = +1 c. zinc oxide Zn = +2 O = -2 d. water H = +1 O = -2 e. calcium hydride Ca = +2 H = -1 f. carbon dioxide C = +4 O = -2 g. nitrogen N = 0 h. sodium sulfate Na = +1 S = +6 O= -2 i. aluminum hydroxide Al = +3 O = -2 H = +1 j. magnesium phosphate Mg = +2 P = +5 O = -2 4. In each of the following reactions, determine what element was oxidized and what element was reduced. a. Ca + H2O
CaO + H2 i. element oxidized calcium ii. element reduced hydrogen b. 2 H2 + O2
2 H2O i. element oxidized hydrogen ii. element reduced oxygen7 Oxidation State Worksheet In each of the following chemicals, determine the oxidation states of each element: 1) sodium nitrate ____________________________________ 2) ammonia ____________________________________ 3) zinc oxide ____________________________________ 4) water ____________________________________ 5) calcium hydride ____________________________________ 6) carbon dioxide ____________________________________ 7) nitrogen ____________________________________ 8) sodium sulfate ____________________________________ 9) aluminum hydroxide ____________________________________ 10) magnesium phosphate ____________________________________ In each of the following reactions, determine what was oxidized and what was reduced. 11) Ca + H2O
CaO + H2 Element oxidized: ____________________________________ Element reduced: ____________________________________ 12) 2 H2 + O2
2 H2O Element oxidized: ____________________________________ Element reduced: ____________________________________8 Oxidation State Worksheet – Solutions In each of the following chemicals, determine the oxidation states of each element: 1) sodium nitrate: Na, +1; N, +5; O, -2 2) ammonia: N, -3; H, +1 3) zinc oxide: Zn, +2: O, -2 4) water: H, +1; O, -2 5) calcium hydride: H, -1; Ca, +2 6) carbon dioxide: C, +4; O, -2 7) nitrogen: N, 0 8) sodium sulfate: Na, +1; S, +6; O, -2 9) aluminum hydroxide: Al, +3; H, +1; O, -2 10) magnesium phosphate: Mg, +2; P, +5; O, -2 In each of the following reactions, determine what was oxidized and what was reduced. 11) Ca + H2O
CaO + H2 Element oxidized: calcium, from 0 to +2 Element reduced: hydrogen, from +1 to 0 12) 2 H2 + O2
2 H2O Element oxidized: hydrogen, from 0 to +1 Element reduced: oxygen, from 0 to -29 Ranking Oxidizing Agents 1. The following equations represent spontaneous reactions. From this evidence, set up a table of relative strengths of oxidizing and reducing agents. Write half-reaction equations and label the strongest oxidizing agent and reducing agent. spont. Co(s) + Pd2+(aq) → Co2+(aq) + Pd(s) spont. Pd(s) + Pt2+(aq) → Pd2+(aq) + Pt(s) spont. Mg(s) + Co2+(aq) → Mg2+(aq) + Co(s) 2. The following equations are interpretations of the evidence from the reactions of four metals with various cation solutions. Make a table of half-reactions and arrange the four metallic ions and the hydrogen ion in order of their decreasing tendency to react. Label the strongest oxidizing agent and reducing agent. spont. Cd(s) + 2 H+(aq) → Cd2+(aq) + H2(g) nonspont. Hg(s) + 2 H+(aq) → Hg2+(aq) + H2(g) spont. Be(s) + Cd2+(aq) → Be2+(aq) + Cd(s) nonspont. Ca2+(aq) + Be(s) → Ca(s) + Be2+(aq) 3. Four metals were placed into test tubes containing various ion solutions. Their resulting behaviour is communicated by the equations below. Create a half-reaction table and order the metallic ions and the hydrogen ion according to their tendency to react. Label the strongest oxidizing agent and reducing agent. nonspont. Pt(s) + 2 H+(aq) → Pt2+(aq) + H2(g) spont. 2 Ce(s) + 3 Ni2+(aq) → 2 Ce3+(aq) + 3 Ni(s) spont. 3 Sr(s) + 2 Ce3+(aq) → 3 Sr2+(aq) + 2 Ce(s) spont. Ni(s) + 2 H+(aq) → Ni2+(aq) + H2(g) 4. A student is required to store an aqueous solution of iron(III) nitrate. She has a choice of a copper, tin, iron, or silver container. Use the table of relative strengths of oxidizing and reducing agents in Appendix I and an appropriate generalization to predict which container would be most suitable for storing the solution. 5. An analytical chemist reacts an unknown metal X with a copper(II) sulfate solution, plating out copper metal. Metal X does not react with aqueous zinc nitrate. What is the order for these metal ions in decreasing tendency to react? What groups of metals are eliminated as a possible identity of the unknown metal? What other solutions might next be chosen to help identify the unknown metal? 6. Build a table of reduction ½ reactions using the following data