Chem 12 - U7 LG
.pdf
School
North Delta Secondary**We aren't endorsed by this school
Course
CHEMISTRY 12
Subject
Chemistry
Date
Dec 19, 2024
Pages
11
Uploaded by CaptainRiverFly23
Chemistry 12 V2: 2024-06-09Page 1of 11Unit 7 Learning Guide Name: ____________________________ Instructions Using a pencil, complete the following questions as you work through the related lessons. Show ALL work,as is explained in the lessons. Do your best and always ask questions if there is anything that you don’t understand.Please print out the Formula Sheet and found at the start of the course. You will need this to do assignments and tests! 7.1 Electrochemistry 1. What is the difference between a reduction reaction and an oxidation reaction? 2. What simple phrase involving a majestic animal should help you remember this difference? Explain how it works! 3. One way to keep agents straight is to think of them as spies who are secret agents for the other side. Try to explain what is meant by this statement. 4. What is the difference between an electrochemical cell and an electrolytic cell?
Chemistry 12 V2: 2024-06-09Page 2of 115. Define oxidation number 6. What is the oxidation number of any element in its standard state? 7. If you see a charge on an individual ion, what will the oxidation number for that ion be? 8. What is the most common oxidation number for hydrogen in compounds? 9. What is the most common oxidation number for oxygen in compounds? 10. Determine the oxidation number of each of the following. Note that the same element can have different oxidation numbers in different compounds. Species Work/Explanation Oxidation Number Au H in H2Na in Na2S S in Na2S S in Na2S2O6O in BaO2P in AlPO4
Chemistry 12 V2: 2024-06-09Page 3of 1111. Put the oxidation of each underlined element below it. Determine if each underlined element has undergone reduction, oxidation or no change. Reaction Oxidation/Reduction/No Change P4becomes PO43- BaO2becomes BaO H2S becomes H2SO4Mn4+becomes MnO2H2O becomes KH 7.2 The Standard Reduction Table 12. The oxidizing agents on the left side of the Standard Reduction Potentials of Half Cells are all undergoing what chemical process? 13. What diagonal shape is drawn on The Standard Reduction Table between two species which would undergo a spontaneous reaction? 14. What diagonal shape is drawn on The Standard Reduction Table between two species which would NOT undergo a spontaneous reaction?
Chemistry 12 V2: 2024-06-09Page 4of 1115. Answer yes or no to each of the following. Be careful with the "is it safe to store" questions! Situation Yes/No Will neutral water oxidize strontium metal? Is it safe to store copper metal in water? If fluorine gas is bubbled into water, is there a reaction? Could an mercury (II) nitrate solution be stored in a silver container? Is it safe to have lithium solid anywhere near fluorine gas? Will hydrochloric acid (H+and Cl-) react with Tin Metal? Will hydrochloric acid (H+and Cl-) react with Manganese (IV) oxide? 16. Give the symbol for a cation that will oxidize calcium but not magnesium. 17. If you place Fe3+ions in a basic solution a reaction will occur but you will not see any solid iron metal forming. Explain why this is so. 18. In the past when balancing reactions you only had to worry about making sure each type of atom was balanced. Now you have two new things to balance. One of those is overall charge. In other words if you have an overall +2 charge in your reactants you must also have an overall charge of +2 in your products. What is the final thing you must ensure is balanced when creating correct redox reactions?
Chemistry 12 V2: 2024-06-09Page 5of 1119. Write a balanced net ionic equation for the redox reaction that occurs given each of the following sets of reactants. Be careful to identify spectator ions and not include them in your calculations. a) Cl2(g)and Ni(s)b) Br2(g)and Al(s) c) Acidified KMnO4and KI d) Au(NO3)3and neutral water. You should not have fractional coefficients in your final answer!
Chemistry 12 V2: 2024-06-09Page 6of 1120. The four metals, Strontium(Sr), Francium (Fr), Yttrium (Y), and Europium (Eu), in separate experiments, are dipped in aqueous solutions of Sr(NO3)2, FrNO3, Y(NO3)3, and Eu(NO3)2. The following results are obtained: 1.Yttrium metal does not react with any of the solutions 2.Strontium metal reacts with all of the other metals solutions 3.Francium metal reacts in a solution of Eu(NO3)2a) List the four oxidizing agents in order from strongest to weakest by creating a small reduction table. Explain your reasoning below! Oxidizing Agents Reducing Agents b) List the four reducing agents in order from strongest to weakest
Chemistry 12 V2: 2024-06-09Page 7of 117.3 Balancing Reactions 21. What are the names of the two methods used to balance redox reactions? 22. Balance the following using the oxidation number method. Start by writing the oxidation number of each atom in each compound beneath it. Explain your steps in the space below Cr2O72-+ S(s)Cr3++ SO32-...in acid Overall 23. Balance the following using the oxidation number method. Start by writing the oxidation number of each atom in each compound beneath it MnO2+ BrO3-MnO4-+ Br2(l)...in base Overall
Chemistry 12 V2: 2024-06-09Page 8of 1124. Balance the following using the half reaction method. NO3-+ Hg(l)Hg2++ NO(g)...in acid Mercury Half Reaction: Nitrogen Half Reaction Overall
Chemistry 12 V2: 2024-06-09Page 9of 1125. Balance the following using the half reaction method. PO33-+ ClO4-PO43-+ Cl-...in base Phosphorus Half Reaction: Chlorine Half Reaction Overall 26. Balance the following using the half reaction method. AuCl4-+ H2Au(s)+ 4 Cl-+ 2H+...in base Gold Half Reaction: Hydrogen Half Reaction Overall
Chemistry 12 V2: 2024-06-09Page 10of 11UNIT 7–ANSWER KEY7.1 Electrochemistry 10. Species Work/Explanation Oxidation Number H in H2Element 0 S in Na2S S2-has charge 2- -2 O in BaO2This is a peroxide 2 + 2x = 0 X = -1 -1 11. Reaction Oxidation/Reduction/No Change H2S becomes H2SO4-2 +6 Oxidation (+8) 7.2 The Standard Reduction Table 19. b) Br2(g)and Al(s)( Br2(g)+ 2e- 2Br-) x 3 + ( Al Al3+ + 3e-) x 2 2Al + 3Br2(g)2 Al3++ 6Br-
Chemistry 12 V2: 2024-06-09Page 11of 117.3 Balancing Reactions 22. 2 Cr2O72-+ 3 S(s)+ 10 H+4 Cr3++ 3 SO32-+ 5 H2O 23. 10 MnO2+ 6 BrO3-+ 4 OH-10 MnO4-+ 3 Br2(l)+ 2 H2O 24. 3 Hg(l) + 2 NO3-+ 8 H+3 Hg2++ 2 NO(g) + 4 H2O 25. 4 PO33-+ 1 ClO4-4 PO43-+ 1 Cl- 26. 2 AuCl4-+ 3 H2+ 6 OH-2 Au(s)+ 8 Cl-+ 6 H2O