Electrochemical Cells
|
|
- Samuel Wiggins
- 6 years ago
- Views:
Transcription
1 Chapter 11 Electrochemical Cells work to be done. Zn gets oxidized and its standard reduction potential is ve (076 V) while that of Cu is +ve (+034 V). The standard cell potential is therefore E =1.10 V. Electrochemical cells can be divided into two types a) galvanic, which converts chemical energy (association sector) into electrical work and b) electrolytic, in which The former can be used to charge a battery (it is in fact a battery) and the latter uses electrical energy to drive a reaction. One can move from a) galvanic to b) electrolytic by simply changing the external potential, and by finding the balance point, determine the cell potential, which is just an electron intensive version of the free energy change. To understand how this is done, we have to understand what happens when, e.g. a metal such as Zn(s) is immersed in a ZnSO 4 solution. A tiny amount of the Zn(s) dissolves leaving the e s on the metal. Thus the metal builds up a slight ve charge and the surrounding solution builds up a slight +ve charge. While the total amount of charge is tiny, the built-up voltages can be significant ( 1 ) and thus the the work required to move charged species is not the standard chemical potential We have to work with a new quantity which accounts for theworkrequiredtomovecharge(eithere s or charged ions) in a medium with a spacially varying electrostatic potential Consider the Daniell cell: Zn(s) ZnSO 4 (aq) CuSO 4 (aq) Cu. The denotes a phase boundary and the asalt bridge. The latter is inserted to make the process quasistationary and thus allow for the maximum (non-pv) ig. Galvanic (chemical electrical) Electrochemical potential Consider the following sequence of simple experiments. 1. Bring together two dissimilar metals (A and B). The level diagrams indicate the delocalized electron quantum levels (particle in a box levels). The top most energy, the energy required to add or subtract one e,is which is also called the ermi energy, As the metals are different, it is extremely unlikely that the ermi energies are equal, as a result there will be a charge transfer. With a transfer of e from A, theasidebecomes+veandthebside ve. This decreases (increases) the (electro) chemical potential corrected for the electrostatic potential for e s on the A (B) side yielding = 81
2 ig. Dissimilar metals 3. Now separate the metals ig. Sep. diss. metals+conn.+vm + = + As = 1 = ( ) Lesson: The difference in chemical potentials induces a matter motion which induces electrical potential difference. When The (+ve) potential will be greater on side A, thus reducing the energy of e, exactly compensating for the greater chemical potential. The electrochemical potential is + (11.1) This definition amounts to subsuming the electrical work sector into an enhanced (pseudo) chemical sector. Note that if the species is neutral ( =0)or the potential is zero, =0 = The charge carried by one mole of charge is araday s constant =96485 [ ]. Now add connections ( and R via identical metal, thus they posses the same electron chemical potentials) to a high impedance voltmeter. ig. Dissimilar metals+connections+vm = ; = = = but as = + = + ( )=[ ] ( ) ( )= [ ] +( ) voltmeter = chemical + electrical. 4. It is the electrochemical difference which dictates material flow. The equilibrium condition becomes = P =0 This can be viewed as the combination of the old chemical sector n and the new electrical potential sector Of course, the new sector only is present if the charge (z) is finite. 11. Conventions, Notation and Standard states 1. The work required to move a charge = from a phase to another through a potential difference is =( )[] =( )[]. The electromotive force is defined as the potential difference measured between stationary thermodynamic states. (recalling: non-pv = ) = = = = = Lesson: Connecting different metals via similar wires to a voltmeter will read zero (unless the sides are different temperatures.) = [ ] (11.) 3. Consider the Daniell cell : Zn Zn ++ Cu ++ Cu (a) Strong electrolytes (sulfates in this case) are used to from the ions in the half cells. (b) The signifies a phase boundary across which charge can be transferred. 8
3 (c) Salt bridge ( ), between half cells, allows charge transport without mixing of the cells. It does this by having a great reservoir of electrolyte (such as KCl) suspended in a gel. This electrolyte diffuses into the cells, and the electrolyte in each half cell, only encroaches slightly into the salt bridge. (The bridge also removes the so called junction potential caused by the boundary between dissimilar solutions.) (d) The circuit is completed with an external wires (of the same material) connected to a voltmeter. (e) An equilibrium between the metal and the ion is established. In the case of Zn, some more of the Zn dissolves leaving the metal -ve and the solution +ve. This potential (of the 1/ cell) cannot be measured by sticking the second electrode in the solution. 4. Electrochemical references (a) If we use identical metals on the two sides (to connect to the voltmeter) we can take the reference electron chemical potential as zero, 0 thus (b) or the neutral metal atoms: = (11.3) = (11.4) (c) or metal ions, once eq. has been established, M + +ze thus =( +)+ =( + + ) = + (11.5) This statement (consequence of 0) is also true for the reference state, = = + 0 (d) Returning to the electrochemical potential of the ion, =0 = (11.6) 5. To set this reference (of = 0, since the absolute is unmeasureable) we choose H + under the conditions of the Standard Hydrogen Electrode. ig. SHE 6. (a) The cell is assembled by bubbling H (g), with P (really f) = 1 bar over a Pt electrode immersed in a H + solution of activity + =1. (b) The reaction and equilibrium condition are: + ()+ 1 () [ + ()] + = 1 () using our reference [ +()] + = 1 () (c) Using the standard states and the offsets for concentrations and nonidealities, the eq. condition becomes [ + ln + +] + = 1 ( ()+ ln ) (d) Thus the potential becomes + = ( + + ln + )[ 1 ( + ln )] = ln + (e) With a reference state of unit activities and fugacities, the ln term vanishes. urthermore, as H (g) is the reference state for H,thereference potential is + = + 1 = + (f) With the reference chemical potential of H + [ (+ )= + () =1 0] and thus we are consistent. + 0 (11.7) 11.3 Reactions & the Nernst Eq. Rather than working the example in the text (the Daniell cell), I will work though the thermodynamics with a different cell. 1. The half reactions are (a) Ox : ++ + ; [ ]=07618 (b) Red:()+ ()+ ; ( )=033 83
4 . How much can we get from this cell? = + P = + P where theextentofreactionisdefined by = 1 = + = +( + ) thus + P = +( + ) =( )+ P =( ) P However from the second law (..)5 0(Recall = ) Therefore P 5 = = () Lesson: the electrical work done BY a cell is equal to the decrement in the Gibbs.E. when done reversibly and less otherwise. 3. The above is true for standard and actual conditions. Therefore, = + ln{ ++ } and as X is 1 in a pure solid, = + ln{ ++ } = + ln{ ++ } = ln{ ++ } More generally, one has the Nernst Equation = ln (11.8). = ln{ } = 1 as = =1 ln{ } 3. Therefore, if we know and measure = = + =( + +)( ) = ±± 4. Thus, = ( )ln{ ±±} = ()ln{ ± } ()ln{ ± } This can be rearranged to get [ +()ln{ ± }] 1 measure =[ ()ln{±}] deduce Noting that in the limit lim 0 (with no other ions in solution), (a) ln ± ± (b) lim 0 [] = Aplotof =[ +()ln{ ± }] 1 vs ± will extrapolate to as 0 5. With and ( ) you can calculate ± ( ) = ()ln{ ±} ()ln{±} by recalling that ± =( + + ) 1 1:1 =1 1 = igs. Just an electron intensive rewrite of = + ln 4. or future reference, 98 = V Cell potentials How do you get the numbers in the table? Consider combining the AgCl Ag electrode (used above) with the SHE. Writing them out in the standard format, Oxidation reduction H (g) HCl(m ) AgCl Ag(s) 1. The half reactions are (a) Ox : 1 () + ()+ (b) Red: ()+ ()+ 1 (c) Net: ()+() ( )+ with = = 11.5 A few pointers & reminders 1. = and = +. [ ] e extensive [= ] e intensive 3. Thus when adding cells, Hess s rule becomes = + 84
5 4. This means when one is dealing with a OX-RED pair (which must be balanced in the e transfer) = + = + The E values ARE per unit e transferred NOT, like the energy functions, per unit of reaction! 11.6 The E ( ) As the cell EM s are just an e intensive measure of the increment function for E 0 are just a scaled version of those for However, one can also get and from E ( ) Lets see how. 1. = ( ) = ( ).. As = + = ( ) or = ( ) 3. = = + = + ( ) = [ ( ) ] external ( ) circuit one can measure the potential difference between the LHS and RHS. Recall that the EM is just an ( ) intensive version of the =. Therefore, if we can measure we can get Specifically, we will vary and measure against a constant LHS. Lets see how. 1. irst let me remind you how is related to Consider the for moving from the LHS =( ) ( ) =( + ln )( + ln ). In the amalgam case we have the same reference states (LHS and RHS). = ln 3. As = = = ln or = {ln +ln ln } 4. We can obtain values of or from the EM s by a simple graph. Rearranging the above equation, y +ln =ln ln ( ) for which the intercept at =0( =1 ln =0)isln and the difference from the intercept at finite is ln 11.7 *Another example Imagine two dilute solid solutions of Pb in Hg (with different mole fractions of Pb ( ) in contact with a common (but separated by a salt bridge) electrolyte. These solid solutions are called amalgams. The chemical potential of the s can be (and generally are) different in the two different solid solutions. This means that s will move from one side to the other in response to the generalized force mismatch (on the s) on one side versus the other. In addition, if the electrolyte consists of a Pb ++ salt, Pb ++ will migrate from one amalgam to the solution to the other amalgam, under the influence of the different = Of course, for this to happen, a path (external circuit) must be provided for the s. The salt bridge holds off attainmentof equilibrium and thus allows for the measurement of the. ollowing convention, we always write the half reaction (amalgam in this case) that provides the s on the LHS. This means that oxidation occurs on the left and reduction on the RHS. If one adds a galvanometer to the 85
CHM 213 (INORGANIC CHEMISTRY): Applications of Standard Reduction Potentials. Compiled by. Dr. A.O. Oladebeye
CHM 213 (INORGANIC CHEMISTRY): Applications of Standard Reduction Potentials Compiled by Dr. A.O. Oladebeye Department of Chemistry University of Medical Sciences, Ondo, Nigeria Electrochemical Cell Electrochemical
More informationElectrochemical Cells
Electrochemical Cells There are two types: Galvanic and Electrolytic Galvanic Cell: a cell in which a is used to produce electrical energy, i.e., Chemical energy is transformed into Electrical energy.
More informationCh. 13 Fundamentals of Electrochemistry
Ch. 13 Fundamentals of Electrochemistry 13.1 13-1. Basic Concepts of electrochemistry redox reaction : reactions with electron transfer oxidized : loses electrons reduced : gains electrons Fe 3+ + V 2+
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 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 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 informationELECTROCHEMISTRY I. The science concerned with the study of electron transfer across phase boundary
ELECTROCHEMISTRY I The science concerned with the study of electron transfer across phase boundary Electrode: Is a conducting material immersed in a media. Electrode potential: Is the potential difference
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. 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 information18.2 Voltaic Cell. Generating Voltage (Potential) Dr. Fred Omega Garces. Chemistry 201. Miramar College. 1 Voltaic Cell.
18.2 Voltaic Cell Generating Voltage (Potential) Dr. Fred Omega Garces Chemistry 201 Miramar College 1 Voltaic Cell Redox Between If Zn (s) and Cu 2+ (aq) is in the same solution, then the electrons transfer
More information#13 Electrochemical Cells
#13 Electrochemical Cells If a copper strip is placed in a solution of copper ions, one of the following reactions may occur: Cu 2+ + 2e - Cu Cu Cu 2+ + 2e - The electrical potential that would be developed
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 informationELECTROCHEMICAL CELLS NAME ROW PD
4-26-12 NAME ROW PD (1) Which statement describes the redox reaction that occurs when an object is electroplated? The diagram below shows the electrolysis of fused KCl. A) It is spontaneous and requires
More informationCHAPTER 6 - Chemical Equilibrium. b. composition when equilibrium is reached.
CHAPTER 6 - Chemical Equilibrium I. Thermodynamics of Chemical Reactions. A. Spontaneity of Chemical Reactions: 1. Thermodynamics can tell us: a. direction of spontaneous change. b. composition when equilibrium
More informationElectrochemical Reactions
1 of 20 4/11/2016 1:00 PM Electrochemical Reactions Electrochemical Reactions Electrical Work From Spontaneous Oxidation- Reduction Reactions Predicting Spontaneous Redox Reactions from the Sign of E Line
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 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 informationGalvanic Cells Spontaneous Electrochemistry. Electrolytic Cells Backwards Electrochemistry
Today Galvanic Cells Spontaneous Electrochemistry Electrolytic Cells Backwards Electrochemistry Balancing Redox Reactions There is a method (actually several) Learn one (4.10-4.12) Practice (worksheet)
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 informationWe can use chemistry to generate electricity... this is termed a Voltaic (or sometimes) Galvanic Cell
Unit 6 Electrochemistry Chemistry 020, R. R. Martin Electrochemistry Electrochemistry is the study of the interconversion of electrical and chemical energy. We can use chemistry to generate electricity...
More informationChapter 7 Electrochemistry
Chapter 7 Electrochemistry Outside class reading Levine: pp. 417 14.4 Galvanic cells: pp. 423 14.5 types of reversible electrodes 7.6.1 Basic concepts of electrochemical apparatus (1) Electrochemical apparatus
More information8. ELECTROCHEMICAL CELLS. n Electrode Reactions and Electrode Potentials a. H 2 2H + + 2e. Cl 2 + 2e 2Cl. H 2 + Cl 2 2H + + 2Cl ; z = 2
8. ELECTROCHEMICAL CELLS n Electrode Reactions and Electrode Potentials 8.1. a. H H + + e Cl + e Cl H + Cl H + + Cl ; z = E = E RT F ln ( a H +a Cl ) b. Hg(l)+ Cl Hg Cl + e H + + e H Hg + H + + Cl Hg Cl
More informationOxidation-Reduction (Redox) Reactions (4.4) 2) The ox. state of an element in a simple ion is the charge of the ion. Ex:
Redox reactions: Oxidation-Reduction (Redox) Reactions (4.4) Oxidation & reduction always occur simultaneously We use OXIDATION NUMBERS to keep track of electron transfers Rules for Assigning Oxidation
More informationChemistry 2000 Lecture 15: Electrochemistry
Chemistry 2000 Lecture 15: Electrochemistry Marc R. Roussel February 21, 2018 Marc R. Roussel Chemistry 2000 Lecture 15: Electrochemistry February 21, 2018 1 / 33 Electrochemical cells Electrochemical
More informationWhat is a Voltaic Cell? Voltaic Cells a.k.a. Electrochemical cells. May 25, Voltaic Cells 2018.notebook
What is a? s a.k.a. Electrochemical cells Aim: To analyze the process of a spontaneous chemical reaction that produces electricity. Voltaic cell: an electrochemical cell where chemical energy is spontaneously
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 informationElectrode Potentials and Their Measurement
Electrochemistry Electrode Potentials and Their Measurement Cu(s) + 2Ag + (aq) Cu(s) + Zn 2+ (aq) Cu 2+ (aq) + 2 Ag(s) No reaction Zn(s) + Cu 2+ (aq) Cu(s) + Zn 2+ (aq) In this reaction: Zn (s) g Zn 2+
More informationElectrochemistry C020. Electrochemistry is the study of the interconversion of electrical and chemical energy
Electrochemistry C020 Electrochemistry is the study of the interconversion of electrical and chemical energy Using chemistry to generate electricity involves using a Voltaic Cell or Galvanic Cell (battery)
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 informationIf you like us, please share us on social media. The latest UCD Hyperlibrary newsletter is now complete, check it out.
Sign In Forgot Password Register username username password password Sign In If you like us, please share us on social media. The latest UCD Hyperlibrary newsletter is now complete, check it out. ChemWiki
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 informationIntroduction. can be rewritten as follows: Oxidation reaction. H2 2H + +2e. Reduction reaction: F2+2e 2F. Overall Reaction H2+F2 2H + +2F
Electrochemistry is the study of chemical processes that cause electrons to move. This movement of electrons is called electricity, which can be generated by movements of electrons from one element to
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 informationChemistry 132 NT. Electrochemistry. Oxidation-Reduction Reactions
Chemistry 132 NT If you ever catch on fire, try to avoid seeing yourself in the mirror, because I bet that s what really throws you into a panic. Jack Handey 1 Chem 132 NT Electrochemistry Module 1 HalfReactions
More informationElectrochemistry. To use principles of electrochemistry to understand the properties of electrochemical cells and electrolysis.
Electrochemistry Objectives: To use principles of electrochemistry to understand the properties of electrochemical cells and electrolysis. Background: Part I: Galvanic Cells: A Galvanic cell is a device
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 informationChemistry Instrumental Analysis Lecture 18. Chem 4631
Chemistry 4631 Instrumental Analysis Lecture 18 Oxidation/Reduction Reactions Transfer of electrons in solution from one reactant to another. Ce +4 + Fe +2 Ce +3 + Fe +3 Ce +4 and Fe 3+ Fe 2+ and Ce 3+
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 informationpossesses negative potential & undergoes oxidation preferably act as ANODE
ELECTROCHEMISTRY Introduction: Electrochemistry is the area of Chemistry dealing with the interconversion of electrical energy and chemical energy. There are many applications of this in every day life.
More informationElectrochemistry. Redox reactions. Half Reactions. Nernst Equation Ion selective electrodes
Electrochemistry Nernst Equation Ion selective electrodes Redox reactions oxidation - loss of electrons M n+ M n+1 + e - M is oxidized - reducing agent reduction - gain of electrons N n+ + e - N n-1 N
More informationIntroduction to Electrochemical reactions. Schweitzer
Introduction to Electrochemical reactions Schweitzer Electrochemistry Create and or store electricity chemically. Use electricity to drive a reaction that normally would not run. Plating metal onto a metal
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 informationSection A: Summary Notes
ELECTROCHEMICAL CELLS 25 AUGUST 2015 Section A: Summary Notes Important definitions: Oxidation: the loss of electrons by a substance during a chemical reaction Reduction: the gain of electrons by a substance
More informationHg2 2+ (aq) + H2(g) 2 Hg(l) + 2H + (aq)
The potential difference between two electrodes in a cell is called the electromotive force, or The EMF of a voltaic cell is called the The cell voltage of a voltaic cell will be a Note: We are used to
More informationELEMENTS OF ELEC TROCHEMIS TRY. A. A number of analytical techniques are based upon oxidation-reduction reactions.
Page 1 of 8 Chem 201 Winter 2006 I. Introduction ELEMENTS OF ELEC TROCHEMIS TRY A. A number of analytical techniques are based upon oxidationreduction reactions. B. Examples of these techniques would include:
More informationA + B C +D ΔG = ΔG + RTlnKp. Me n+ + ne - Me. Me n n
A + B C +D ΔG = ΔG + RTlnKp Me n+ + ne - Me K p a a Me Me n a n e 1 mol madde 6.2 x 1 23 atom elektron yükü 1.62 x 1-19 C FARADAY SABİTİ: 6.2 x 1 23 x 1.62 x 1-19 = 96485 A.sn (= coulomb) 1 Faraday 965
More information5) do sample calculations 1) In electrogravimetry, analyte deposited as a solid ("plated") onto one of the electrodes.
Page 1 of 1 Chem 201 Lecture 8b Summer 09 Return tests Last time: 0) Intro to Electrochemistry 1) E, Galvanic cells Today: Potentiometry Lecture: GALVANIC CELLS: -spontaneous reaction is utilized. ; voltaic
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 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 informationELECTROCHEMISTRY. these are systems involving oxidation or reduction there are several types METALS IN CONTACT WITH SOLUTIONS OF THEIR IONS
Electrochemistry 1 ELECTROCHEMISTRY REDOX Reduction gain of electrons Cu 2+ (aq) + 2e > Cu(s) Oxidation removal of electrons Zn(s) > Zn 2+ (aq) + 2e HALF CELLS these are systems involving oxidation or
More informationElectrochemistry and the Nernst Equation
Electrochemistry and the Nernst Equation LEARNING OBJECTIVES The objectives of this experiment are to... construct galvanic cells and develop an electrochemical series based on potential differences between
More informationModule-1: Electrode Potential And Cells 2015
Lecture-2 Standard Electrode potential Standard electrode potential is the electrode potential when the metal is in contact with a solution of its own ions of unit concentration (1M) at 298K. If the electrode
More informationFundamentals of Electrochemistry
Fundamentals of Electrochemistry: Lecture 1 Fundamentals of Electrochemistry CHEM*7234 / CHEM 720 Lecture 1 Course Overview Date Topic Instructor Thurs 8 Fri 9 Mon 12 Tues 13 Wed 14 Thurs 15 Fri 16 Mon
More informationUnit 2 Electrochemical methods of Analysis
Unit 2 Electrochemical methods of Analysis Recall from Freshman Chemistry: Oxidation: Loss of electrons or increase in the oxidation number Fe 2 e - Fe 3 Reduction: Gain of electrons or decreases in the
More informationUNIT 3 ELECTROCHEMISTRY
95414101 UNIT 3 ELECTROCHEMISTRY 1 MARK QUESTIONS Q. 1. Which solution will allow greater conductance of electricity, 1 M NaCl at 93 K or 1 M NaCl at 33 K and why? Ans. 1 M NaCl at 33 K as the ionic mobilities
More informationChemistry 213. Electrochemistry I
1 Chemistry 213 Electrochemistry I Electrochemical Cells Objective Oxidation/reduction reactions find their most important use in the construction of voltaic cells (chemical batteries). In this experiment,
More informationChemistry 213. Electrochemistry
Chemistry 213 Electrochemistry Part A: Electrochemical Cells Objective Oxidation/reduction reactions find their most important use in the construction of voltaic cells (chemical batteries). In this experiment,
More informationChapter Objectives. Chapter 13 Electrochemistry. Corrosion. Chapter Objectives. Corrosion. Corrosion
Chapter Objectives Larry Brown Tom Holme Describe at least three types of corrosion and identify chemical reactions responsible for corrosion. www.cengage.com/chemistry/brown Chapter 13 Electrochemistry
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 informationLab.12. Electrochemistry
Key words: oxidation, reduction, anode, cathode, potential, galvanic cell, Nernst equation, electromotive force Literature: D.A. Skoog, F.J. Holler, T.A. Nieman: Principles of Instrumental Analysis J.
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 informationThis chapter is concerned with galvanic cells, in which a chemical reaction produces an electric
Electrochemical Cells 8 PREVIEW This chapter is concerned with galvanic cells, in which a chemical reaction produces an electric potential difference between two electrodes. An example is the Daniell cell,
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 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 informationChem 321 Lecture 16 - Potentiometry 10/22/13
Student Learning Objectives Chem 321 Lecture 16 - Potentiometry 10/22/13 In lab you will use an ion-selective electrode to determine the amount of fluoride in an unknown solution. In this approach, as
More informationlect 26:Electrolytic Cells
lect 26:Electrolytic Cells Voltaic cells are driven by a spontaneous chemical reaction that produces an electric current through an outside circuit. These cells are important because they are the basis
More informationELECTROCHEMICAL CELLS
ELECTROCHEMICAL CELLS Electrochemistry 1. Redox reactions involve the transfer of electrons from one reactant to another 2. Electric current is a flow of electrons in a circuit Many reduction-oxidation
More informationAP CHEMISTRY NOTES 12-1 ELECTROCHEMISTRY: ELECTROCHEMICAL CELLS
AP CHEMISTRY NOTES 12-1 ELECTROCHEMISTRY: ELECTROCHEMICAL CELLS Review: OXIDATION-REDUCTION REACTIONS the changes that occur when electrons are transferred between reactants (also known as a redox reaction)
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 18 problems (with solutions)
Chapter 18 problems (with solutions) 1) Assign oxidation numbers for the following species (for review see section 9.4) a) H2SO3 H = +1 S = +4 O = -2 b) Ca(ClO3)2 Ca = +2 Cl = +5 O = -2 c) C2H4 C = -2
More informationREDOX EQUILIBRIA AND FEASIBILITY OF A REACTION
REDOX EQUILIBRIA AND FEASIBILITY OF A REACTION Oxidizing agent Reducing agent Oxidation-Reduction Reactions Electron transfer reactions Electrons transferred from one substance to another Change in oxidation
More information1.11 Electrochemistry
1.11 Electrochemistry Recap from 1.7: Oxidation and Reduction: Oxidation and Reduction: Oxidation and reduction reactions can be identified by looking at the reaction in terms of electron transfer: Definitions:
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 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 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 informationStructure & properties of water
OCN 623 Chemical Oceanography Reading: Libes, Chapter 7 Structure & properties of water Water accounts for 96.5 weight percent of seawater Innate characteristics affect nearly all properties of seawater
More informationTopic 5.3 REDOX EQUILIBRIA. Oxidation and Reduction Electrochemical Cells and Fuel Cells The Electrochemical Series Spontaneous Reactions
Topic 5.3 REDOX EQUILIBRIA Oxidation and Reduction Electrochemical Cells and Fuel Cells The Electrochemical Series Spontaneous Reactions OXIDATION AND REDUCTION Redox reactions were studied extensively
More informationGeneral Chemistry 1412 Spring 2008 Instructor: Dr. Shawn Amorde Website:
General Chemistry 1412 Spring 2008 Instructor: Dr. Shawn Amorde Website: www.austincc.edu/samorde Email: samorde@austincc.edu Lecture Notes Chapter 21 (21.1-21.25) Suggested Problems () Outline 1. Introduction
More informationElectrochemistry and the Nernst Equation
Experiment Electrochemistry and the Nernst Equation The CCLI Initiative Computers in Chemistry Laboratory Instruction The objectives of this experiment are to... LEARNING OBJECTIVES construct galvanic
More informationName AP CHEM / / Collected Essays Chapter 17
Name AP CHEM / / Collected Essays Chapter 17 1980 - #2 M(s) + Cu 2+ (aq) M 2+ (aq) + Cu(s) For the reaction above, E = 0.740 volt at 25 C. (a) Determine the standard electrode potential for the reaction
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 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 informationCHAPTER 6 Modern Theory Principles LECTURER SAHEB M. MAHDI
CHAPTER 6 Modern Theory Principles LECTURER SAHEB M. MAHDI Modern Theory principles in Corrosion and their applications :- Corrosion studies can be carried-out by two methods 1 Thermodynamics. or 2 By
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 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 informationmccord (pmccord) HW11 Electrochemistry I mccord (51520) 1
mccord (pmccord) HW11 Electrochemistry I mccord (51520) 1 This print-out should have 27 questions. Multiple-choice questions may continue on the next column or page find all choices before answering. 001
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 informationElectrochemical methods : Fundamentals and Applications Introduction
Electrochemical methods : Fundamentals and Applications Introduction March 05, 2014 Kwang Kim Yonsei University kbkim@yonsei.ac.kr 39 8 7 34 53 Y O N Se I 88.91 16.00 14.01 78.96 126.9 Electrochemical
More information(c) Na is deposited at the cathode (d) Na appears at the anode
year chemiry n0tes new CHAPTER 10 ELECTROCHEMISTRY MCQS Q.1 Electrolysis is the process in which a chemical reaction takes place at the expense of (a) chemical energy (b) electrical energy (c) heat energy
More informationGalvanic cells. Galvanic cells (2) Alessandro Giuseppe Antonio Anastasio Baron Volta. John Frederic Daniell
A quote of the week (or camel of the week): I have no special talents. I am only passionately curious Albert Einstein Physical Chemistry EPM/7 1 Galvanic cells Galvanic cells are devices permitting direct
More informationElectrochemistry. Electrochemical Process. The Galvanic Cell or Voltaic Cell
Electrochemistry Electrochemical Process The conversion of chemical energy into electrical energy and the conversion of electrical energy into chemical energy are electrochemical process. Recall that an
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 informationElectro Chemistry Part-II 1. Faraday s laws of electrolysis are related to the 1) Molar mass of the electrolyte 2) Equivalent weight of the cation or anion 3) Molecular mass of the electrolyte 4) Atomic
More information8.1. Measurement of the electromotive force of an electrochemical cell
8.. Measurement of the electromotive force of an electrochemical cell Ojectives: Measurement of electromotive forces ( the internal resistances, investigation of the dependence of ) and terminal voltages
More informationHomework 11. Electrochemical Potential, Free Energy, and Applications
HW11 Electrochemical Poten!al, Free Energy, and Applica!ons Homework 11 Electrochemical Potential, Free Energy, and Applications Question 1 What is the E for Zn(s) Zn (aq) Ce (aq) Ce (aq) + cell + 4+ 3+
More informationWhat is the importance of redox reactions? Their importance lies in the fact that we can use the transfer of electrons between species to do useful
What is the importance of redox reactions? Their importance lies in the fact that we can use the transfer of electrons between species to do useful work. This is accomplished by constructing a voltaic
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 informationEquilibrium electrochemistry
Equilibrium electrochemistry The principles of thermodynamics can be applied to solutions of electrolytes. For that we need to take into account activity coefficients: they differ significantly from 1
More informationUnit - 3 ELECTROCHEMISTRY VSA QUESTIONS (1 - MARK QUESTIONS) 3. Mention the purpose of salt-bridge placed between two half-cells of a galvanic cell?
Unit - 3 ELECTROCHEMISTRY 1. What is a galvanic cell? VSA QUESTIONS (1 - MARK QUESTIONS) 2. Give the cell representation for Daniell Cell. 3. Mention the purpose of salt-bridge placed between two half-cells
More information