Electrode Potentials and Their Measurement
|
|
- Monica McCoy
- 5 years ago
- Views:
Transcription
1 Electrochemistry
2 Electrode Potentials and Their Measurement Cu(s) + 2Ag + (aq) Cu(s) + Zn 2+ (aq) Cu 2+ (aq) + 2 Ag(s) No reaction
3
4 Zn(s) + Cu 2+ (aq) Cu(s) + Zn 2+ (aq) In this reaction: Zn (s) g Zn 2+ (aq) Oxidation Cu 2+ (aq) g Cu (s) Reduction
5
6
7 If Zn (s) and Cu 2+ (aq) is in the same solution, then the electron is a transferred directly between the Zn and Cu. No useful work is obtained. However if the reactants are separated and the electrons shuttle through an external path...
8
9 An Electrochemical Cell/2 (Daniell) Anode (-) Negative electrode generates electrons Oxidation occurs Cathode (+) Positive electrode accepts electrons Reduction occurs Zn(s) Zn 2+ (aq) Cu 2+ (aq) Cu(s) ΔE cell = V
10 An Electrochemical Cell/1 Anode (-) Negative electrode generates electrons Oxidation occurs Cathode (+) Positive electrode accepts electrons Reduction occurs Cu(s) Cu 2+ (aq) Ag + (aq) Ag(s) ΔE cell = V
11 Electron Transfer at the Electrodes Anode Cathode
12 Terminology Electromotive force, ΔE cell. The cell voltage or cell potential. Cell diagram. Shows the components of the cell in a symbolic way. Anode (where oxidation occurs) on the left. Cathode (where reduction occurs) on the right. Boundary between phases shown by. Boundary between half cells (usually a salt bridge) shown by. Couple, M Mn + A pair of species related by a change in number of e -.
13 Terminology Galvanic cells. Produce electricity as a result of spontaneous reactions. Electrolytic cells. Non-spontaneous chemical change driven by electricity.
14 Standard Electrode Potentials Cell voltages, the potential differences between electrodes, are among the most precise scientific measurements. The potential of an individual electrode is difficult to establish. Arbitrary zero is chosen. The Standard Hydrogen Electrode (SHE)
15 Standard Hydrogen Electrode 2 H + (a = 1) + 2 e - D H 2 (g, 1 bar) E = 0 V Pt H 2 (g, 1 bar) H + (a = 1)
16 Standard Electrode Potential, E E defined by international agreement. The tendency for a reduction process to occur at an electrode. All ionic species present at a = 1 (approximately 1 M). All gases are at 1 bar (approximately 1 atm). Where no metallic substance is indicated, the potential is established on an inert metallic electrode (ex. Pt).
17 Reduction Couples Cu 2+ (1M) + 2 e - D Cu(s) E Cu 2+ /Cu =? Pt H 2 (g, 1 bar) H + (a = 1) Cu 2+ (1 M) Cu(s) ΔE cell = V anode cathode Standard cell potential: the potential difference of a cell formed from two standard electrodes. ΔE cell = E cathode - E anode
18 Standard Cell Potential Pt H 2 (g, 1 bar) H + (a = 1) Cu 2+ (1 M) Cu(s) ΔE cell = V ΔE cell = E cathode - E anode ΔE cell = E Cu 2+ /Cu - E H + /H V = E Cu 2+ /Cu - 0 V E Cu 2+ /Cu = V H 2 (g, 1 atm) + Cu 2+ (1 M) D 2H + (1 M) + Cu(s) ΔE cell = V
19 Measuring Standard Reduction Potential anode cathode cathode anode
20 Standard Reduction Potentials Most spontaneous <Reduction occurs> Oxidizing Agent Most nonspontaneous Spontaneous in the reverse direction. <Oxidation occurs> Reducing Agent
21 ΔE cell, ΔG, and K eq Cells do electrical work. Moving electric charge. w elec, rev = ΔG = -QΔE Faraday constant, F = 96,488 C mol -1 = q N A = C mol -1 = charge of one mole of electrons. ΔG = -nfδe ΔG = -nfδe
22 Spontaneous Change ΔG < 0 for spontaneous change. Therefore ΔE cell > 0 because ΔG cell = -nfδe cell ΔE cell > 0 Reaction proceeds spontaneously as written. ΔE cell = 0 Reaction is at equilibrium. ΔE cell < 0 Reaction proceeds in the reverse direction spontaneously.
23 The Behavior or Metals Toward Acids M(s) D M 2+ (aq) + 2 e - E = -E M 2+ /M 2 H + (aq) + 2 e - D H 2 (g) E H + /H 2 = 0 V 2 H + (aq) + M(s) D H 2 (g) + M 2+ (aq) ΔE cell = E H + /H 2 - E M 2+ /M = -E M 2+ /M When E M 2+ /M < 0, E cell > 0. Therefore ΔG < 0. Metals with negative reduction potentials react with acids
24
25
26 ΔE cell, ΔG, and K eq Cells do electrical work. Moving electric charge. w elec, rev = ΔG = -QΔE Faraday constant, F = 96,488 C mol -1 = q N A = C mol -1 = charge of one mole of electrons. ΔG = -nfδe ΔG = -nfδe
27 Relationship Between ΔE cell and K eq ΔG = -RT ln K eq = -nfδe cell 0 ΔE cell = RT nf ln K eq
28 Summary of Thermodynamic, Equilibrium and Electrochemical Relationships.
29 ΔE cell as a Function of Concentration ΔG = ΔG +RT ln Q -nfδe cell = -nfδe cell +RT ln Q 0 ΔE cell = ΔE cell RT nf lnq R = J K 1 mol 1 F = C mol 1 T = 298K Convert to log 10 and calculate constants The Nernst Equation: 0 ΔE cell = ΔE cell n logq
30 Example Applying the Nernst Equation for Determining ΔE cell. What is the value of ΔE cell for the voltaic cell pictured below and diagrammed as follows? Pt Fe 2+ (0.10 M),Fe 3+ (0.20 M) Ag + (1.0 M) Ag(s)
31 Pt Fe 2+ (0.10 M),Fe 3+ (0.20 M) Ag + (1.0 M) Ag(s) Fe 2+ (aq) + Ag + (aq) D Fe 3+ (aq) + Ag (s) 0 ΔE cell = ΔE cell n logq 0 ΔE cell = ΔE cell n log Fe 2+ Fe 3+ Ag+ ΔE cell = V V = V
32 ΔE cell as a Function of Concentration: an Alternative Route Cathode: Ox 1 è Red 1 Anode: Red 2 è Ox 2
33 Alternative Route C A
34
35
36 Combining Half-Cell Reactions/1 Reaction 1: Cu 2+ (aq) + 2e - D Cu(s) Reaction 2: Cu + (aq) + e - D Cu(s) Reaction 3: Cu 2+ (aq) + e - D Cu + (aq) Since Reaction 3 = Reaction 1 - Reaction 2 NO!!
37 Reaction 1: Cu 2+ (aq) + 2e - D Cu(s) Reaction 2: Cu + (aq) + e - D Cu(s) Reaction 3: Cu 2+ (aq) + e - D Cu + (aq)
38 Combining Half Reactions/2 Fe 3+ (aq) + 3e - D Fe(s) E Fe 3+ /Fe =? Fe 2+ (aq) + 2e - D Fe(s) E Fe 2+ /Fe = V Fe 3+ (aq) + e - D Fe 2+ (aq) E Fe 3+ /Fe 2+ = V 1 2 Fe 3+ (aq) + 3e - D Fe(s) E Fe 3+ /Fe = V 3 Equation 3 = Equation 1 + Equation 2
39 Dismutation/1 Spontaneous
40 Dismutation/2 Non-spontaneous
41 Concentration Cells Two half cells with identical electrodes but different ion concentrations. Pt H 2 (1 atm) H + (x M) H + (1.0 M) H 2 (1 atm) Pt(s) 2 H + (1 M) + 2 e - D H 2 (g, 1 atm) H 2 (g, 1 atm) D 2 H + (x M) + 2 e - 2 H + (1 M) D 2 H + (x M)
42 Concentration Cells 2 H + (1 M) D 2 H + (x M) 0 ΔE cell = ΔE cell n logq 0 ΔE cell = ΔE cell log x2 1 2 ΔE cell = log x = ph
43 Measurement of K sp Ag Ag + (sat d AgI) Ag + (0.10 M) Ag(s) Ag + (0.100 M) + e - D Ag(s) Ag(s) D Ag + (sat d) + e - Ag + (0.100 M) D Ag + (sat d M)
44 Example Using a Voltaic Cell to Determine K sp of a Slightly Soluble Solute. With the date given for the reaction on the previous slide, calculate K sp for AgI. AgI(s) D Ag + (aq) + I - (aq) Let [Ag + ] in a saturated Ag + solution be x: 0 ΔE cell = ΔE cell = log Ag C 1 log Ag+ A = log Ag+ Ag C = log Ag A = log Ag + A Ag + A = ( ) ( ) 2 = K S 0 = log Ag + A = A
45 Batteries: Producing Electricity Through Chemical Reactions Primary Cells (or batteries). Cell reaction is not reversible. Secondary Cells. Cell reaction can be reversed by passing electricity through the cell (charging). Flow Batteries and Fuel Cells. Materials pass through the battery which converts chemical energy into electric energy.
46 The Leclanché (Dry) Cell
47 Dry Cell Oxidation: Zn(s) D Zn 2+ (aq) + 2 e - Reduction: 2 MnO 2 (s) + H 2 O(l) + 2 e - D Mn 2 O 3 (s) + 2 OH - Acid-base reaction: NH OH - D NH 3 (g) + H 2 O(l) Precipitation reaction: NH 3 + Zn 2+ (aq) + Cl - [Zn(NH 3 ) 2 ]Cl 2 (s)
48 Alkaline Dry Cell Reduction: 2 MnO 2 (s) + H 2 O(l) + 2 e - D Mn 2 O 3 (s) + 2 OH - Oxidation reaction can be thought of in two steps: Zn(s) D Zn 2+ (aq) + 2 e - Zn 2+ (aq) + 2 OH - D Zn (OH) 2 (s) Zn (s) + 2 OH - D Zn (OH) 2 (s) + 2 e -
49 Lead-Acid (Storage) Battery The most common secondary battery
50 Lead-Acid Battery Reduction: PbO 2 (s) + 3 H + (aq) + HSO 4- (aq) + 2 e - D PbSO 4 (s) + 2 H 2 O(l) Oxidation: Pb (s) + HSO 4- (aq) D PbSO 4 (s) + H + (aq) + 2 e - PbO 2 (s) + Pb(s) + 2 H + (aq) + HSO 4- (aq) D 2 PbSO 4 (s) + 2 H 2 O(l) ΔE cell = E - E PbO 2/PbSO4 PbSO4/Pb = 1.74 V ( 0.28 V) = 2.02 V
51 The Silver-Zinc Cell: A Button Battery Zn(s),ZnO(s) KOH(sat d) Ag 2 O(s),Ag(s) Zn(s) + Ag 2 O(s) D ZnO(s) + 2 Ag(s) E cell = 1.8 V
52 The Nickel-Cadmium Cell Cd(s) + 2 NiO(OH)(s) + 2 H 2 O(L) D 2 Ni(OH) 2 (s) + Cd(OH) 2 (s)
53 Fuel Cells O 2 (g) + 2 H 2 O(l) + 4 e - D 4 OH - (aq) 2{H 2 (g) + 2 OH - (aq) D 2 H 2 O(l) + 2 e - } 2H 2 (g) + O 2 (g) D 2 H 2 O(l) ΔE cell = ΔE O 2/OH - - ΔE H2O/H2 = V ( V) = V
Electrochemistry. The study of the interchange of chemical and electrical energy.
Electrochemistry The study of the interchange of chemical and electrical energy. Oxidation-reduction (redox) reaction: involves a transfer of electrons from the reducing agent to the oxidizing agent. oxidation:
More informationPart One: Introduction. a. Chemical reactions produced by electric current. (electrolysis)
CHAPTER 19: ELECTROCHEMISTRY Part One: Introduction A. Terminology. 1. Electrochemistry deals with: a. Chemical reactions produced by electric current. (electrolysis) b. Production of electric current
More information17.1 Redox Chemistry Revisited
Chapter Outline 17.1 Redox Chemistry Revisited 17.2 Electrochemical Cells 17.3 Standard Potentials 17.4 Chemical Energy and Electrical Work 17.5 A Reference Point: The Standard Hydrogen Electrode 17.6
More informationElectrochemistry Pulling the Plug on the Power Grid
Electrochemistry 18.1 Pulling the Plug on the Power Grid 18.3 Voltaic (or Galvanic) Cells: Generating Electricity from Spontaneous Chemical Reactions 18.4 Standard Electrode Potentials 18.7 Batteries:
More informationChapter 20. Electrochemistry. Chapter 20 Problems. Electrochemistry 7/3/2012. Problems 15, 17, 19, 23, 27, 29, 33, 39, 59
Chemistry, The Central Science, 11th edition Theodore L. Brown; H. Eugene LeMay, Jr.; and Bruce E. Bursten Chapter 20 John D. Bookstaver St. Charles Community College Cottleville, MO Chapter 20 Problems
More informationHow to Assign Oxidation Numbers. Chapter 18. Principles of Reactivity: Electron Transfer Reactions. What is oxidation? What is reduction?
Chapter 18 Principles of Reactivity: Electron Transfer Reactions What is oxidation? When a molecule/ion loses electrons (becomes more positive) Whatever is oxidized is the reducing agent What is reduction?
More informationElectron Transfer Reactions
ELECTROCHEMISTRY 1 Electron Transfer Reactions 2 Electron transfer reactions are oxidation- reduction or redox reactions. Results in the generation of an electric current (electricity) or be caused by
More informationElectrochemistry objectives
Electrochemistry objectives 1) Understand how a voltaic and electrolytic cell work 2) Be able to tell which substance is being oxidized and reduced and where it is occuring the anode or cathode 3) Students
More informationOxidation number. The charge the atom would have in a molecule (or an ionic compound) if electrons were completely transferred.
Oxidation number The charge the atom would have in a molecule (or an ionic compound) if electrons were completely transferred. 1. Free elements (uncombined state) have an oxidation number of zero. Na,
More informationElectrochemistry. Chapter 18. Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Electrochemistry Chapter 18 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1 Electrochemical processes are oxidation-reduction reactions in which: the energy
More informationElectrochemistry 1 1
Electrochemistry 1 1 Half-Reactions 1. Balancing Oxidation Reduction Reactions in Acidic and Basic Solutions Voltaic Cells 2. Construction of Voltaic Cells 3. Notation for Voltaic Cells 4. Cell Potential
More informationELECTROCHEMISTRY OXIDATION-REDUCTION
ELECTROCHEMISTRY Electrochemistry involves the relationship between electrical energy and chemical energy. OXIDATION-REDUCTION REACTIONS SPONTANEOUS REACTIONS Can extract electrical energy from these.
More informationCh 20 Electrochemistry: the study of the relationships between electricity and chemical reactions.
Ch 20 Electrochemistry: the study of the relationships between electricity and chemical reactions. In electrochemical reactions, electrons are transferred from one species to another. Learning goals and
More informationOxidation-Reduction Review. Electrochemistry. Oxidation-Reduction Reactions. Oxidation-Reduction Reactions. Sample Problem.
1 Electrochemistry Oxidation-Reduction Review Topics Covered Oxidation-reduction reactions Balancing oxidationreduction equations Voltaic cells Cell EMF Spontaneity of redox reactions Batteries Electrolysis
More informationChapter 17. Electrochemistry
Chapter 17 Electrochemistry Contents Galvanic cells Standard reduction potentials Cell potential, electrical work, and free energy Dependence of cell potential on concentration Batteries Corrosion Electrolysis
More informationChapter Nineteen. Electrochemistry
Chapter Nineteen Electrochemistry 1 Electrochemistry The study of chemical reactions through electrical circuits. Monitor redox reactions by controlling electron transfer REDOX: Shorthand for REDuction-OXidation
More informationQ1. Why does the conductivity of a solution decrease with dilution?
Q1. Why does the conductivity of a solution decrease with dilution? A1. Conductivity of a solution is the conductance of ions present in a unit volume of the solution. On dilution the number of ions per
More informationElectrochemistry. Dr. A. R. Ramesh Assistant Professor of Chemistry Govt. Engineering College, Kozhikode
Electrochemistry Dr. A. R. Ramesh Assistant Professor of Chemistry Govt. Engineering College, Kozhikode 1 Electro Chemistry : Chemistry of flow of electrons Redox Reaction The electrons flow through the
More informationCHEM J-8 June /01(a)
CHEM1001 2012-J-8 June 2012 22/01(a) A galvanic cell has the following cell reaction: D(s) + 2Zn 2+ (aq) 2Zn(s) + D 4+ (aq) Write the overall cell reaction in shorthand cell notation. E = 0.18 V 8 D(s)
More informationChapter 9 Oxidation-Reduction Reactions. An Introduction to Chemistry by Mark Bishop
Chapter 9 Oxidation-Reduction Reactions An Introduction to Chemistry by Mark Bishop Chapter Map Oxidation Historically, oxidation meant reacting with oxygen. 2Zn(s) + O 2 (g) 2ZnO(s) Zn Zn 2+ + 2e or 2Zn
More informationChapter 20 Electrochemistry
Chapter 20 Electrochemistry Learning goals and key skills: Identify oxidation, reduction, oxidizing agent, and reducing agent in a chemical equation Complete and balance redox equations using the method
More informationReview. Chapter 17 Electrochemistry. Outline. Voltaic Cells. Electrochemistry. Mnemonic
Review William L Masterton Cecile N. Hurley Edward J. Neth cengage.com/chemistry/masterton Chapter 17 Electrochemistry Oxidation Loss of electrons Occurs at electrode called the anode Reduction Gain of
More informationChapter 19 ElectroChemistry
Chem 1046 General Chemistry by Ebbing and Gammon, 9th Edition George W.J. Kenney, Jr, Professor of Chemistry Last Update: 11July2009 Chapter 19 ElectroChemistry These Notes are to SUPPLIMENT the Text,
More informationDry Cell: a galvanic cell with the electrolyte contained in a paste thickened by starch. anode and an inert graphite cathode.
1 BATTERIES Text Pages: 764-766, 787,788 Battery: a set of galvanic cells connected in series - The negative electrode of one cell is connected to the positive electrode of the next cell - The total voltage
More informationElectrochemical System
Electrochemical System Topic Outcomes Week Topic Topic Outcomes 8-10 Electrochemical systems It is expected that students are able to: Electrochemical system and its thermodynamics Chemical reactions in
More informationCHEM J-12 June 2013
CHEM1101 2013-J-12 June 2013 In concentration cells no net chemical conversion occurs, however a measurable voltage is present between the two half-cells. Explain how the voltage is produced. 2 In concentration
More informationCHEMISTRY 13 Electrochemistry Supplementary Problems
1. When the redox equation CHEMISTRY 13 Electrochemistry Supplementary Problems MnO 4 (aq) + H + (aq) + H 3 AsO 3 (aq) Mn 2+ (aq) + H 3 AsO 4 (aq) + H 2 O(l) is properly balanced, the coefficients will
More informationElectrochemistry. Review oxidation reactions and how to assign oxidation numbers (Ch 4 Chemical Reactions).
Electrochemistry Oxidation-Reduction: Review oxidation reactions and how to assign oxidation numbers (Ch 4 Chemical Reactions). Half Reactions Method for Balancing Redox Equations: Acidic solutions: 1.
More informationChapter 7. Oxidation-Reduction Reactions
Chapter 7 Oxidation-Reduction Reactions Chapter Map Oxidation Historically oxidation meant reacting with oxygen. 2Zn(s) + O 2 (g) 2ZnO(s) Zn Zn 2+ + 2e or 2Zn 2Zn 2+ + 4e O + 2e O 2 or O 2 + 4e 2O 2 Oxidation
More informationCHEM J-14 June 2014
CHEM1101 2014-J-14 June 2014 An electrochemical cell consists of an Fe 2+ /Fe half cell with unknown [Fe 2+ ] and a Sn 2+ /Sn half-cell with [Sn 2+ ] = 1.10 M. The electromotive force (electrical potential)
More informationDr. Anand Gupta
By Dr Anand Gupta Mr. Mahesh Kapil Dr. Anand Gupta 09356511518 09888711209 anandu71@yahoo.com mkapil_foru@yahoo.com Electrochemistry Electrolysis Electric energy Chemical energy Galvanic cell 2 Electrochemistry
More informationChapter 20. Electrochemistry
Chapter 20. Electrochemistry 20.1 Oxidation-Reduction Reactions Oxidation-reduction reactions = chemical reactions in which the oxidation state of one or more substance changes (redox reactions). Recall:
More informationName: Regents Chemistry Date:
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
More informationElectrochemistry. 1. For example, the reduction of cerium(iv) by iron(ii): Ce 4+ + Fe 2+ Ce 3+ + Fe 3+ a. The reduction half-reaction is given by...
Review: Electrochemistry Reduction: the gaining of electrons Oxidation: the loss of electrons Reducing agent (reductant): species that donates electrons to reduce another reagent. Oxidizing agent (oxidant):
More informationChapter 18 Electrochemistry. Electrochemical Cells
Chapter 18 Electrochemistry Chapter 18 1 Electrochemical Cells Electrochemical Cells are of two basic types: Galvanic Cells a spontaneous chemical reaction generates an electric current Electrolytic Cells
More informationChapter 18. Electrochemistry
Chapter 18 Electrochemistry Oxidation-Reduction Reactions Review of Terms Oxidation-reduction (redox) reactions always involve a transfer of electrons from one species to another. Oxidation number - the
More informationChapter 17 Electrochemistry
Chapter 17 Electrochemistry 17.1 Galvanic Cells A. Oxidation-Reduction Reactions (Redox Rxns) 1. Oxidation = loss of electrons a. the substance oxidized is the reducing agent 2. Reduction = gain of electrons
More informationElectrochemistry. Remember from CHM151 G E R L E O 6/24/2014. A redox reaction in one in which electrons are transferred.
Electrochemistry Remember from CHM151 A redox reaction in one in which electrons are transferred Reduction Oxidation For example: L E O ose lectrons xidation G E R ain lectrons eduction We can determine
More informationTopic 19 Redox 19.1 Standard Electrode Potentials. IB Chemistry T09D04
Topic 19 Redox 19.1 Standard Electrode Potentials IB Chemistry T09D04 19.1 Standard Electrode Potentials 19.1.1 Describe the standard hydrogen electrode. (2) 19.1.2 Define the term standard electrode potential,
More informationChapter 20. Electrochemistry
Chapter 20. Electrochemistry 20.1 OxidationReduction Reactions Oxidationreduction reactions = chemical reactions in which the oxidation state of one or more substance changes (redox reactions). Recall:
More informationLecture Presentation. Chapter 18. Electrochemistry. Sherril Soman Grand Valley State University Pearson Education, Inc.
Lecture Presentation Chapter 18 Electrochemistry Sherril Soman Grand Valley State University Harnessing the Power in Nature The goal of scientific research is to understand nature. Once we understand the
More information12.05 Galvanic Cells. Zn(s) + 2 Ag + (aq) Zn 2+ (aq) + 2 Ag(s) Ni(s) + Pb 2+ (aq) «Ni 2+ (aq) + Pb(s)
12.05 Galvanic Cells 1. In an operating voltaic cell, reduction occurs A) at the anode B) at the cathode C) in the salt bridge D) in the wire 2. Which process occurs in an operating voltaic cell? A) Electrical
More informationChemistry: The Central Science. Chapter 20: Electrochemistry
Chemistry: The Central Science Chapter 20: Electrochemistry Redox reaction power batteries Electrochemistry is the study of the relationships between electricity and chemical reactions o It includes the
More informationChapter 19: Electrochemistry
Chapter 19: Electrochemistry Overview of the Chapter review oxidation-reduction chemistry basics galvanic cells spontaneous chemical reaction generates a voltage set-up of galvanic cell & identification
More informationLecture 14. Thermodynamics of Galvanic (Voltaic) Cells.
Lecture 14 Thermodynamics of Galvanic (Voltaic) Cells. 51 52 Ballard PEM Fuel Cell. 53 Electrochemistry Alessandro Volta, 1745-1827, Italian scientist and inventor. Luigi Galvani, 1737-1798, Italian scientist
More informationELECTROCHEMISTRY. Oxidation/Reduction
ELECTROCHEMISTRY Electrochemistry involves the relationship between electrical energy and chemical energy. OXIDATION-REDUCTION REACTIONS SPONTANEOUS REACTIONS Examples: voltaic cells, batteries. NON-SPONTANEOUS
More informationChapter 19: Oxidation - Reduction Reactions
Chapter 19: Oxidation - Reduction Reactions 19-1 Oxidation and Reduction I. Oxidation States A. The oxidation rules (as summarized by Mr. Allan) 1. In compounds, hydrogen has an oxidation # of +1. In compounds,
More informationCHAPTER 17 ELECTROCHEMISTRY
Advanced Chemistry Approximate Timeline Students are expected to keep up with class work when absent. CHAPTER 17 ELECTROCHEMISTRY Day Plans for the day Assignment(s) for the day 17.1 Galvanic Cells Assignment
More informationChapter 19 - Electrochemistry. the branch of chemistry that examines the transformations between chemical and electrical energy
Chapter 19 - Electrochemistry the branch of chemistry that examines the transformations between chemical and electrical energy 19.1 Redox Chemistry Revisited A Spontaneous Redox Reaction Znº(s) + Cu 2+
More informationElectrochemistry. Galvanic Cell. Page 1. Applications of Redox
Electrochemistry Applications of Redox Review Oxidation reduction reactions involve a transfer of electrons. OIL- RIG Oxidation Involves Loss Reduction Involves Gain LEO-GER Lose Electrons Oxidation Gain
More informationElectrochemistry. (Hebden Unit 5 ) Electrochemistry Hebden Unit 5
(Hebden Unit 5 ) is the study of the interchange of chemical energy and electrical energy. 2 1 We will cover the following topics: Review oxidation states and assigning oxidation numbers Redox Half-reactions
More informationLecture Presentation. Chapter 20. Electrochemistry. James F. Kirby Quinnipiac University Hamden, CT Pearson Education, Inc.
Lecture Presentation Chapter 20 James F. Kirby Quinnipiac University Hamden, CT is the study of the relationships between electricity and chemical reactions. It includes the study of both spontaneous and
More informationZn+2 (aq) + Cu (s) Oxidation: An atom, ion, or molecule releases electrons and is oxidized. The oxidation number of the atom oxidized increases.
Oxidation-Reduction Page 1 The transfer of an electron from one compound to another results in the oxidation of the electron donor and the reduction of the electron acceptor. Loss of electrons (oxidation)
More informationTypes of Cells Chemical transformations to produce electricity- Galvanic cell or Voltaic cell (battery)
Electrochemistry Some Key Topics Conduction metallic electrolytic Electrolysis effect and stoichiometry Galvanic cell Electrolytic cell Electromotive Force Electrode Potentials Gibbs Free Energy Gibbs
More information25. A typical galvanic cell diagram is:
Unit VI(6)-III: Electrochemistry Chapter 17 Assigned Problems Answers Exercises Galvanic Cells, Cell Potentials, Standard Reduction Potentials, and Free Energy 25. A typical galvanic cell diagram is: The
More informationCHEMISTRY - CLUTCH CH.18 - ELECTROCHEMISTRY.
!! www.clutchprep.com CONCEPT: OXIDATION-REDUCTION REACTIONS Chemists use some important terminology to describe the movement of electrons. In reactions we have the movement of electrons from one reactant
More informationReview: Balancing Redox Reactions. Review: Balancing Redox Reactions
Review: Balancing Redox Reactions Determine which species is oxidized and which species is reduced Oxidation corresponds to an increase in the oxidation number of an element Reduction corresponds to a
More informationNCEA Chemistry 3.7 REDOX AS 91393
NCEA Chemistry 3.7 REDOX AS 91393 This achievement standard involves demonstrating understanding of oxidation-reduction processes Demonstrate comprehensive understanding (Excellence) involves: 1. Identify
More informationCHEM J-14 June 2014
CHEM1101 2014-J-14 June 2014 An electrochemical cell consists of an Fe 2+ /Fe half cell with unknown [Fe 2+ ] and a Sn 2+ /Sn half-cell with [Sn 2+ ] = 1.10 M. The electromotive force (electrical potential)
More informationLecture #15. Chapter 18 - Electrochemistry
Lecture #15 Chapter 18 - Electrochemistry Chapter 18 - Electrochemistry the branch of chemistry that examines the transformations between chemical and electrical energy Redox Chemistry Revisited A Spontaneous
More informationΔG = -nfe cell. Electrode Potentials. The cell potential E cell is related to the free energy of the reaction ΔG by:
Electrode Potentials Ahmad Aqel Ifseisi Assistant Professor of Analytical Chemistry College of Science, Department of Chemistry King Saud University P.O. Box 2455 Riyadh 11451 Saudi Arabia Building: 05,
More informationELECTROCHEMISTRY Chapter 14
ELECTROCHEMISTRY Chapter 14 Basic Concepts: Overview of Electrochemical Process at Constant T, P (14-1) ΔG = ΔG o + RT ln Q = w elec (maximum) = qe = ItE (exp) (E intensive parameter, q extensive) = nfe
More informationSpontaneous Redox Between Zinc Metal and Copper(II) Ions. Zn 2+ Zn + 2e- Cu 2+ NO 3
Spontaneous Redox Between Zinc Metal and Copper(II) Ions Zn 2+ Cu 2+ NO 3 _ Zn + 2e- Cu Zn 0 + Cu 2+ º Zn 2+ + Cu 0 spontaneous red 1 ox 2 ox 1 red 2 Spontaneous Redox Between Copper Metal and Silver Ions
More informationElectrochem 1 Electrochemistry Some Key Topics Conduction metallic electrolytic Electrolysis effect and stoichiometry Galvanic cell Electrolytic cell Electromotive Force (potential in volts) Electrode
More informationRedox reactions & electrochemistry
Redox reactions & electrochemistry Electrochemistry Electrical energy ; Chemical energy oxidation/reduction = redox reactions Electrochemistry Zn + Cu 2+ º Zn 2+ + Cu Oxidation-reduction reactions always
More informationElectrochemistry. A. Na B. Ba C. S D. N E. Al. 2. What is the oxidation state of Xe in XeO 4? A +8 B +6 C +4 D +2 E 0
Electrochemistry 1. Element M reacts with oxygen to from an oxide with the formula MO. When MO is dissolved in water, the resulting solution is basic. Element M is most likely: A. Na B. Ba C. S D. N E.
More informationCHAPTER 5 REVIEW. C. CO 2 D. Fe 2 O 3. A. Fe B. CO
CHAPTER 5 REVIEW 1. The following represents the process used to produce iron from iron III oxide: Fe 2 O 3 + 3CO 2Fe + 3CO 2 What is the reducing agent in this process? A. Fe B. CO C. CO 2 D. Fe 2 O 3
More informationOxidation-reduction (redox) reactions
Oxidation-reduction (redox) reactions Reactions in which there are changes in oxidation state (oxidation number) between reactants and products 2 MnO 4- + 10 Br - + 16 H + 2 Mn 2+ + 5 Br 2 + 8 H 2 O One
More informationLecture Presentation. Chapter 20. Electrochemistry. James F. Kirby Quinnipiac University Hamden, CT Pearson Education
Lecture Presentation Chapter 20 James F. Kirby Quinnipiac University Hamden, CT is the study of the relationships between electricity and chemical reactions. It includes the study of both spontaneous and
More informationChapter 18 Electrochemistry
Chapter 18 Electrochemistry Definition The study of the interchange of chemical and electrical energy in oxidation-reduction (redox) reactions This interchange can occur in both directions: 1. Conversion
More informationN Goalby chemrevise.org
Redox Equilibria Electrochemical cells This type of cell can be called a Voltaic cell or Galvanic cell. Voltaic cells convert energy from spontaneous, exothermic chemical processes to electrical energy.
More informationChapter 18: Electrochemistry
Chapter 18: Electrochemistry Oxidation States An oxidation-reduction reaction, or redox reaction, is one in which electrons are transferred. 2Na + Cl 2 2NaCl Each sodium atom is losing one electron to
More informationOxidation-Reduction (Redox)
Oxidation-Reduction (Redox) Electrochemistry involves the study of the conversions between chemical and electrical energy. Voltaic (galvanic) cells use chemical reactions to produce an electric current.
More informationElectrochemistry (Galvanic and Electrolytic Cells) Exchange of energy in chemical cells
Electrochemistry (Galvanic and Electrolytic Cells) Exchange of energy in chemical cells Oxidation loss of electrons (oxidation number increases) OIL RIG Reduction gain of electrons (oxidation number decreases)
More informationChapter 18. Redox Reac)on. Oxida)on & Reduc)on 4/8/08. Electrochemistry
Chapter 18 Electrochemistry Redox Reac)on One or more elements change oxida)on number all single displacement, and combus)on, some synthesis and decomposi)on Always have both oxida)on and reduc)on split
More informationLecture 30 Chapter 19, Sections 3-4 Galvanic Cells Electrochemical Potential
Lecture 30 Chapter 19, Sections 3-4 Galvanic Cells Electrochemical Potential Galvanic Cells Defined Standard Hydrogen Electrode Standard Reduction Potentials Redox Balancing One More Example OK, then here
More informationElectrochemistry. Outline
Electrochemistry Outline 1. Oxidation Numbers 2. Voltaic Cells 3. Calculating emf or Standard Cell Potential using Half-Reactions 4. Relationships to Thermo, Equilibrium, and Q 5. Stoichiometry 6. Balancing
More informationChemistry 102 Chapter 19 OXIDATION-REDUCTION REACTIONS
OXIDATION-REDUCTION REACTIONS Some of the most important reaction in chemistry are oxidation-reduction (redox) reactions. In these reactions, electrons transfer from one reactant to the other. The rusting
More informationChapter 18. Electrochemistry
Chapter 18 Electrochemistry Section 17.1 Spontaneous Processes and Entropy Section 17.1 http://www.bozemanscience.com/ap-chemistry/ Spontaneous Processes and Entropy Section 17.1 Spontaneous Processes
More informationChapter 21 Electrochemistry
Chapter 21 Electrochemistry - electrochemistry and electrochemical processes are some of the most important sources of power that we have - batteries - much publicized hydrogen fuel cells - photosynthesis
More informationAssigning Oxidation Numbers:
Assigning Oxidation Numbers: 1. Oxidation number of a free element or diatomic molecule is zero. Ex: Na(s), Cu(s), H 2 (g), F 2 (g) 2. In most cases the oxidation number of hydrogen is +1, oxygen is -2,
More information17.1 Redox Reactions. Oxidation Numbers. Assigning Oxidation Numbers. Redox Reactions. Ch. 17: Electrochemistry 12/14/2017. Creative Commons License
Ch. 17: Electrochemistry Electric vehicles contain batteries that can be recharged, thereby using electric energy to bring about a chemical change and vice versa. (credit: modification of work by Robert
More information1.11 Redox Equilibria
1.11 Redox Equilibria Electrochemical cells Electron flow A cell has two half cells. The two half cells have to be connected with a salt bridge. Simple half cells will consist of a metal (acts an electrode)
More informationIntroduction to electrochemistry
Introduction to electrochemistry Oxidation reduction reactions involve energy changes. Because these reactions involve electronic transfer, the net release or net absorption of energy can occur in the
More informationChemistry 112 Name Exam III Form A Section November 13,
Chemistry 112 Name Exam III Form A Section November 13, 2012 email IMPORTANT: On the scantron (answer sheet), you MUST clearly fill your name, your student number, section number, and test form (white
More informationChapter 20 Electrochemistry
Chapter 20 Electrochemistry 20.1 Oxidation States and Oxidation-Reduction Reactions An oxidation occurs when an atom or ion loses electrons. A reduction occurs when an atom or ion gains electrons. One
More informationQUESTION. Electrochemistry. Dry Cell Battery. Electrochemical Processes in Batteries. Chemistry of Batteries QUESTION
Meals Ready to Eat (MREs) were developed during the Vietnam War. They need hot water to be reconstituted. The military includes a small packet of metal to heat the water through an oxidation-reduction
More informationElectrochem: It s Got Potential!
Electrochem: It s Got Potential! Presented by: Denise DeMartino Westlake High School, Eanes ISD Pre-AP, AP, and Advanced Placement are registered trademarks of the College Board, which was not involved
More informationOME General Chemistry
OME General Chemistry Lecture 10: Electrochemistry Dr. Vladimir Lesnyak Office: Physical Chemistry, Erich Müller-Bau, r. 111 Email: vladimir.lesnyak@chemie.tu-dresden.de Phone: +49 351 463 34907 Outline
More informationCHEM Principles of Chemistry II. Chapter 17 - Electrochemistry
CHEM 1212 - Principles of Chemistry II Chapter 17 - Electrochemistry electrochemistry is best defined as the study of the interchange of chemical and electrical energy 17.1 Galvanic Cells an oxidation-reduction
More informationSection Electrochemistry represents the interconversion of chemical energy and electrical energy.
Chapter 21 Electrochemistry Section 21.1. Electrochemistry represents the interconversion of chemical energy and electrical energy. Electrochemistry involves redox (reduction-oxidation) reactions because
More information20.1 Consider the Brønsted-Lowry acid-base reaction and the redox reaction below. + A
20 Electrochemistry Visualizing Concepts 20.1 Consider the Brønsted-Lowry acid-base reaction and the redox reaction below. HA + B BH + + A HA H + + A B + H + BH + X(red) + Y + (ox) X + (ox) + Y(red) X(red)
More informationConsider E, ΔG and K eq NOTES:
Consider E, ΔG and K eq Electrochemical Cell: If E is positive, then the reaction favours. Thermodynamics: If ΔG is negative, then the reaction favours. Obviously E and ΔG are related! They are equated
More informationREDUCTION - OXIDATION TITRATION REDOX TITRATION
References REDUCTION OXIDATION TITRATION REDOX TITRATION 1 Fundamentals of analytical chemistry, Skoog. 2 Analytical chemistry, Gary D. Christian. الكيمياء التحليلية الجامعية تأليف د.هادي حسن جاسم 3 Oxidation
More informationCHAPTER 12. Practice exercises
CHAPTER 12 Practice exercises 12.1 2Al(s) + 3Cl 2 (g) 2AlCl 3 (aq) Aluminium is oxidised and is therefore the reducing agent. Chlorine is reduced and is therefore the oxidising agent. 12.3 First the oxidation
More informationElectrochemistry and battery technology Contents
Electrochemistry and battery technology Contents Introduction Redox overview voltaic cells, electrolytic cells, fuel cells, Primary and secondary batteries. Other batteries; Construction, working and applications
More informationLecture 27 Chapter 19, Sections 3-4 Galvanic Cells Electrochemical Potential
Lecture 27 Chapter 19, Sections 3-4 Galvanic Cells Electrochemical Potential Galvanic Cells Defined Standard Hydrogen Electrode Standard Reduction Potentials Redox Balancing One More Example This time
More information3. Potentials and thermodynamics
Electrochemical Energy Engineering, 2012 3. Potentials and thermodynamics Learning subject 1. Electrochemical reaction 2. Thermodynamics and potential 3. Nernst equation Learning objective 1. To set up
More informationOxidation Numbers, ox #
Oxidation Numbers, ox # are or numbers assigned to each or assuming that the are transferred from the electronegative element to the electronegative element. now mimic systems. ox # are written followed
More informationOxidation (oxidized): the loss of one or more electrons. Reduction (reduced): the gain of one or more electrons
1 of 13 interesting links: Battery Chemistry Tutorial at http://www.powerstream.com/batteryfaq.html Duracell Procell: Battery Chemistry at http://www.duracell.com/procell/chemistries /default.asp I. Oxidation
More information