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http://mcdougall.rockyview.ab.ca/Members/kking/chemistry-30/unit-b-electrochemistry

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chemistry-electrochemical power point chemistry-electrochemical power point Presentation Transcript

  • Electrochemical Cells Reference: Chapter 14 (pg. 610-669)
  • Unit B: Electrochemistry (Chapter 14) • This PowerPoint is available on the Plone Site. • It is your responsibility to print off the notes that you would like. • You will not be able to write everything down in class as this will inhibit the time we have to spend on practicing concepts and performing labs.
  • Assessment (Chapter 13)  Homework will be taken in randomly  1 Quiz will be given in this chapter  Cell Quiz (covering 14.1-14.3)  You should use this to your advantage as they test smaller sections of the curriculum and help prepare you for the Unit Exam  1 Lab Report will be expected  Electrochem Unit Exam at the end of this chapter  Cumulative Exam at the end of this unit  This will cover Organic and Electrochemistry
  • Electrochemical Cells Today’s objectives: 1.Define anode, cathode, anion, cation, salt bridge/porous cup, electrolyte, and voltaic cell 2.Predict and write the half-reaction equation that occurs at each electrode in an electrochemical cell
  • Electrochemical Cells Today’s AGENDA: 1.Introduce Electrochemistry – Focus on Voltaic Cells 2.Voltaic Cell Worksheet – guided practice
  • Introduction to Electrochemistry  An electric cell converts chemical energy into electrical energy    Alessandro Volta invented the first electric cell but got his inspiration from Luigi Galvani. Galvani’s crucial observation was that two different metals could make the muscles of a frog’s legs twitch. Unfortunately, Galvani thought this was due to some mysterious “animal electricity”. It was Volta who recognized this experiment’s potential. An electric cell produces very little electricity, so Volta came up with a better design: A battery is defined as two or more electric cells connected in series to produce a steady flow of current   Volta’s first battery consisted of several bowls of brine (NaCl (aq)) connected by metals that dipped from one bowl to another His revised design, consisted of a sandwich of two metals separated by paper soaked in salt water.
  • Introduction to Electrochemistry   Alessandro Volta’s invention was an immediate technological success because it produced electric current more simply and reliably than methods that depended on static electricity. It also produced a steady electric current –something no other device could do.
  • Introduction to Electrochemistry  Electric cells are composed of two electrodes – solid electrical conductors and at least one electrolyte (aqueous electrical conductor)  In current cells, the electrolyte is often a moist paste (just enough water is added so that the ions can move). Sometimes one electrode is the cell container.  The positive electrode is defined as the cathode and the negative electrode is defined as the anode  The electrons flow through the external circuit from the anode to the cathode.  To test the voltage of a battery, the red(+) lead is connected to the cathode (+ electrode), and the black(-) lead is connected to the anode (- electrode)
  • Introduction to Electrochemistry  A voltmeter is a device that measures the energy difference, per unit charge, between any two points in an electric circuit (called electric potential difference)    I.e. A 9V battery releases 6X as much energy compared with the electrons from a 1.5V battery. The voltage of a cell depends mainly on the chemical composition of the reactants in the cell An ammeter is a device that measures the rate of flow of charge past a point in an electrical circuit (called electric current)  The larger the electric cell, the greater current that can be produced Electric potential difference is Electric potential difference is like the potential energy difference like the potential energy difference between 1kg of water at the top of between 1kg of water at the top of the dam and 1kg of water at the the dam and 1kg of water at the bottom of the dam. bottom of the dam. Electric current (or flow of Electric current (or flow of electrons) is like the flow of the electrons) is like the flow of the water. A larger drain would be like aa water. A larger drain would be like larger electric cell, allowing more larger electric cell, allowing more water (or electrons) to flow. water (or electrons) to flow.
  • Introduction to Electrochemistry  The power of a battery is the rate at which it produces electrical energy. Power is measured in watts (W). Calculated using P = IV (Power = current x potential difference)  The energy density is a measure of the quantity of energy stored or supplied per unit mass. Measured in J/kg.  Table 1 summarizes some important electrical quantities and their units
  • Secondary cells can be recharged Secondary cells can be recharged using electricity, but are expensive using electricity, but are expensive Primary cells cannot be recharged, but Primary cells cannot be recharged, but are relatively inexpensive are relatively inexpensive Fuel cells produce Fuel cells produce electricity by the reaction of electricity by the reaction of aafuel that isiscontinuously fuel that continuously supplied. supplied. More efficient, and used for More efficient, and used for NASA vehicles, but still too NASA vehicles, but still too expensive for general or expensive for general or commercial applications commercial applications
  • Voltaic Cells (aka Galvanic Cell)  A device that spontaneously produces electricity by redox  Uses chemical substances that will participate in a spontaneous redox reaction.   The reduction half-reaction (SOA) will be above the oxidation half-reaction (SRA) in the activity series to ensure a spontaneous reaction. Composed of two half-cells; which each consist of a metal rod or strip immersed in a solution of its own ions or an inert electrolyte.      Electrodes: solid conductors connecting the cell to an external circuit Anode: electrode where oxidation occurs (-) Cathode: electrode where reduction occurs (+) The electrons flow from the anode to the cathode (“a before c”) through an electrical circuit rather than passing directly from one substance to another A porous boundary separates the two electrolytes while still allowing ions to flow to maintain cell neutrality  Often the porous boundary is a salt bridge, containing an inert aqueous electrolyte (such as Na2SO4(aq) or KNO3(aq)),  Or you can use a porous cup containing one electrolyte which sits in a container of a second electrolyte.
  • Voltaic Cells (aka Galvanic Cells)  Voltaic cells can be represented using cell notation: The single line represents aaphase The single line represents phase boundary (electrode to electrolyte) boundary (electrode to electrolyte) and the double line represents aa and the double line represents physical boundary (porous boundary) physical boundary (porous boundary)   The SOA present in the cell always undergoes reduction at the cathode The SRA present in the cell always undergoes oxidation at the anode RED CAT AN OX
  • Match the cell notation to the descriptions a) Sn(s) Sn4+(aq) Cu2+(aq) Cu(s) b) Mg(s) MgCl2(aq) f) Mg(s) Mg2+(aq) Sn(s) SnCl2(aq) Magnesium in a solution of magnesium chloride and tin in a solution of tin(II) chloride A tin(IV) ion solution containing tin and a solution of magnesium ions containing magnesium Two tin electrodes in solution of tin(II) chloride and tin (IV) chloride respectively 6. e) Mg(s) Mg2+(aq) A copper-magnesium cell 5. d) Sn(s) SnCl2(aq) 2. 4. c) Copper placed in a solution of copper(II) chloride and tin metal placed in a solution of tin(II) ions 3. SnCl4(aq) Sn(s) 1. Copper place in a copper(II) solution and tin place in a tin(IV) solution CuCl2(aq) Cu(s) Cu2+(aq) Cu(s) Sn2+(aq) Sn(s) SnCl4(aq) Sn(s)
  • Voltaic Cells – What is going on?  Example: Silver-Copper Cell Cu(s) Cu2+(aq) Ag+(aq) Ag(s) 1. Use the activity series to determine which of the entities is the SOA. The SOA present in the cell always undergoes a reduction at the cathode. Write the reduction half reaction 2. Use the activity series to determine which of the entities is the SRA. The SRA present in the cell always undergoes an oxidation as the anode. Write the oxidation half-reaction 3. The cathode isisthe The cathode the electrode where the electrode where the strongest oxidizing agent strongest oxidizing agent present in the cell present in the cell reacts. reacts. Balance the half-reactions and add together to create the net equation. Memory device: Memory device: “An ox ate aared cat” “An ox ate red cat” Anode oxidation; reduction Anode oxidation; reduction cathode cathode The anode isisthe The anode the electrode where the electrode where the strongest reducing agent strongest reducing agent present in the cell present in the cell reacts. reacts.
  • Voltaic Cells – What is going on?  Example: Silver-Copper Cell  Silver ions are the strongest oxidizing agents in the cell, so they undergo a reduction halfreaction at the cathode, creating more Ag(s)  Copper atoms are the strongest reducing agents in the cell, so they give up electrons in an oxidation half-reaction and enter the solution (Cu2+ = blue ions) at the anode.  Electrons released by the oxidation of copper atoms at the anode travel through the connecting wire to the silver cathode. (Ag+(aq) win in the tug of war for e-’s over Cu2+(aq))  Since the positive silver ions are being removed from solution, you would assume that the solution would become negatively charged. This does not happen. Why?  Cations (positively charged ions) move from the salt bridge into the solution in the cathode compartment to maintain an electrically neutral solution.  Anions (negatively charged ions) move from the salt bridge into the solution in the anode compartment to maintain an electrically neutral solution.
  • Voltaic Cell Voltaic Cell Animation Animation
  • Voltaic Cell Summary  A voltaic cell consists of two-half cells separated by a porous boundary with solid electrodes connected by an external circuit  SOA undergoes reduction at the cathode (+ electrode) – cathode increases in mass  SRA undergoes oxidation at the anode (- electrode) – anode decreases in mass  Electrons always travel in the external circuit from anode to cathode  Internally, cations move toward the cathode, anions move toward the anode, keeping the solution neutral
  • Voltaic Cells with Inert Electrodes  Inert electrodes are needed when the SOA or SRA involved in the reaction is not solid. If this is the case, usually a graphite (C (s)) rod or platinum strip is used as the electrode.   Inert (unreactive) electrodes provide a location to connect a wire and a surface on which a half-reaction can occur. Example: a) Write equations for the half-reactions and the overall reaction that occur in the following cell: C(s) Cr2O72-(aq) H+(aq) Cu2+(aq) Cu(s) cathode: anode: Cr2O72-(aq) + 14 H+(aq)+ 6 e-  2Cr3+(aq) + 7H2O(l) 3 [Cu(s) Cu2+(aq) + 2e- ] 3Cu (s) + Cr2O72-(aq) + 14 H+(aq)  3Cu2+(aq + 2Cr3+(aq) + 7H2O(l) b) Draw a diagram of the cell labeling electrodes, electrolytes, the direction of electron flow and The copper electrode will decrease in mass and the The copper electrode will decrease in mass and the the direction of ion movement. blue colour of the electrolyte increases (Cu2+),),which blue colour of the electrolyte increases (Cu 2+ which indicates oxidation at the anode. indicates oxidation at the anode. The carbon electrode remains unchanged, but the The carbon electrode remains unchanged, but the orange colour of the dichromate solution becomes orange colour of the dichromate solution becomes less intense and changes to greenish-yellow (Cr3+),), less intense and changes to greenish-yellow (Cr3+ evidence that reduction is occurring in this half cell evidence that reduction is occurring in this half cell
  • Homework • Homework Book Pg. 1-3 (Use redox table in textbook pg. 828) • Go through the answers to page 1 as a class • What is coming up tomorrow? • • Voltaic Cell lab coming up Standard Cells and Cell Potentials
  • Electrochemical Cells Today’s objectives: 1.Explain that the values of standard reduction potential are all relative to the E r = 0.00 V set for the hydrogen electrode at standard conditions 2.Calculate the standard cell potential for electrochemical cells 3.Predict the spontaneity of redox reactions based on standard cell potentials
  • Electrochemical Cells Today’s AGENDA: 1.Review Homework 2.Standard Cells and Cell Potentials – guided practice
  • Standard Cells and Cell Potentials  A standard cell is a voltaic cell where each ½ cell contains all entities necessary at SATP conditions and all aqueous solutions have a concentration of 1.0 mol/L  Standardizing makes comparisons and scientific study easier  Standard Cell Potential, E0 cell = the electric potential difference of the cell (voltage) E0 cell = E0r cathode – E0r anode • Where E0r is the standard reduction potential, and is a measure of a standard ½ cell’s ability to attract electrons. • The higher the E0r , the stronger the OA • All standard reduction potentials are based on the standard hydrogen ½ cell being 0.00V. This means that all standard reduction potentials that are positive are stronger OA’s than hydrogen ions and all standard reduction potentials that are negative are weaker. • If the E0 cell is positive, the reaction occurring is spontaneous. • If the E0 cell is negative, the reaction occurring is non-spontaneous
  • Rules for Analyzing Standard Cells 1. Determine which electrode is the cathode. The cathodes is the electrode where the strongest oxidizing agent present in the cell reacts. I.e. The OA that is closet to the top on the left side of the redox table = SOA If required, copy the reduction half-reaction for the strongest oxidizing agent and its reduction potential 1. Determine which electrode is the anode. The anode is the electrode where the strongest reducing agent present in the cell reacts. I.e. The RA that is closet to the bottom on the right side of the redox table = SRA If required, copy the oxidation half-reaction (reverse the half-reaction) 1. Determine the overall cell reaction. Balance the electrons for the two half reactions (but DO NOT change the E0r) and add the half-reaction equations. 2. Determine the standard cell potential, E0cell using the equation: E0 cell = E0r cathode – E0r anode
  • Standard Cells and Cell Potentials #1  Example: What is the standard potential of the cell represented below: 1. Determine the cathode and anode 2. Determine the overall cell reaction 3. Determine the standard cell potential
  • Standard Cells and Cell Potentials #2  Example: What is the standard potential of an electrochemical cell made of a cadmium electrode in a 1.0 mol/L cadmium nitrate solution and chromium electrode in a 1.0 mol/L chromium(III) nitrate solution? SOA Cd2+(aq) SRA Cd(s) Cr2+(aq) Cr(s) H2O(l) cathode anode E0 cell = E0r cathode – E0r anode = (-0.40V) - (-0.91V) = + 0.51V The E0 cell is positive, therefore the reaction is spontaneous.
  • Standard Cells and Cell Potentials #3  Example: A standard lead-dichromate cell is constructed. Write the cell notation, label the electrodes, and calculate the standard cell potential. SRA Pb(s) Pb2+(aq) SOA Cr2O72-(aq) H+(aq) Cr3+(aq) C(s) anode cathode E0 cell = E0r cathode – E0r anode = (+1.23V) - (-0.13V) = + 1.36V The E0 cell is positive, therefore the reaction is spontaneous. Cell Potential Animation Cell Potential Animation
  • Standard Cells and Cell Potentials #4  Example: A standard scandium-copper cell is constructed and the cell potential is measured. The voltmeter indicates that copper the copper electrode is positive. Sc(s) Sc3+(aq) Cu2+(aq) Cu(s) E0 cell = +2.36V anode cathode Write and label the half-reaction and net equations, and calculate the standard reduction potential of the scandium ion. E0 cell = E0r cathode - E0r anode 2.36V = (+0.34V) - (x) E0r anode = -2.02V
  • Homework • Homework Book Pg. 4 (Use redox table in textbook pg. 828) • • • Go through the answers to #1 as a class Lab Exercise 14.A - Analysis What is coming up tomorrow? • • • Voltaic Cell and Cell Potential Lab Start Electrochemical Cells Voltaic Cell and Cell Potential Quiz (in two days)
  • Electrochemical Cells Today’s objectives: 1.Identify the similarities and differences between a voltaic cell and an electrolytic cell 2.Predict the spontaneity of redox reactions based on standard cell potentials. 3.Recognize that predicted reactions do not always occur.
  • Electrochemical Cells Today’s AGENDA: 1.Review Homework 2.Electrolytic Cells w/ demo
  • Electrolytic Cells  The term “electrochemical cell” is often used to refer to a:  Voltaic Cell – one with a spontaneous reaction SOA over SRA on the activity series Eocell greater than zero = spontaneous  Electrolytic cell – one with a nonspontaneous reaction SOA below SRA – i.e. zinc sulfate and lead solid cell Eocell less than zero= nonspontaneous  Why would anyone be interested in a cell that is not spontaneous?  This would certainly not a good battery choice, but by supplying electrical energy to a nonspontaneous cell, we can force this reaction to occur.  This is especially useful for producing substances, particularly elements. I.e. the zinc sulfate cell discussed above is similar to the cell used in the industrial production of zinc metal.
  • Electrolytic Cells  Electrolytic Cell – a cell in which a nonspontaneous redox reaction is forced to occur; a combination of two electrodes, an electrolyte and an external power source.   Electrolysis – the process of supplying electrical energy to force a nonspontaneous redox reaction to occur The external power source acts as an “electron pump”; the electric energy is used to do work on the electrons to cause an electron transfer Electrons are pulled from the Electrons are pulled from the anode and pushed to the cathode anode and pushed to the cathode by the battery or power supply by the battery or power supply
  • Comparing Electrochemical Cells: Voltaic and Electrolytic It is best to think of “positive” and “negative” for electrodes as labels, not charges. It is best to think of “positive” and “negative” for electrodes as labels, not charges.
  • Procedure for Analyzing Electrolytic Cells  Use the redox table to identify the SOA and SRA  Don’t forget to consider water for aqueous electrolytes.  Write equations for the reduction (cathode) and oxidation (anode) halfreactions. Include the reduction potentials if required.  Balance the electrons and write the net cell reaction including the cell potential. E0 cell = E0r cathode - E0r anode  If required, state the minimum electric potential (voltage) to force the reaction to occur. (The minimum voltage is the absolute value of E0 cell)  If a diagram is requested, use the general outline in Figure 6, and add specific labels for chemical entities.
  • Analyzing Electrolytic Cells #1  Example: What are the cell reactions and the cell potential of the aqueous potassium iodide electrolytic cell?  Identify major entities and identify the SOA and SRA.  Write the half-reaction equations and calculate the cell potential.  State the minimum electric potential (voltage) to force the reaction to occur. Electrons must by supplied with aa Electrons must by supplied with minimum of +1.37 V from an external minimum of +1.37 V from an external battery or other power supply to battery or other power supply to force the cell reactions. force the cell reactions.
  • Potassium-Iodide Electrolytic Cell  In the potassium iodide electrolytic cell, litmus paper does not change colour in the initial solution and turns blue only near the electrode from which gas bubbles. Why?  At the other electrode, a yellow-brown colour and a dark precipitate forms. The yellow brown substance produces a purplish-red colour in the halogen test (pg. 805). Why?
  • Analyzing Electrolytic Cells #2  Example: An electrolytic cell containing cobalt(II) chloride solution and lead electrodes is assembled. The notation for the cell is as follows: a) Predict the reactions at the cathode and anode, and in the overall cell. b) Draw and label a cell diagram for this electrolytic cell, including the power supply. c) What minimum voltage must be applied to make this cell work?
  • Analyzing Electrolytic Cells #3  Example: An electrolytic cell is set up with a power supply connected to two nickel electrodes immersed in an aqueous solution containing cadmium nitrate and zinc nitrate.  Predict the equations for the initial reaction at each electrode and the net cell reaction. Calculate the minimum voltage that must be applied to make the reaction occur.
  • The Chloride Anomaly (******Diploma)  Some redox reactions predicted using the SOA and SRA from a redox table do not always occur in an electrolytic cell.  The actual reduction potential required for a particular half-reaction and the reported halfreaction reduction potential may be quite different (depending on the conditions or half-reactions)   This difference is known as the half-cell overvoltage. “As an empirical rule, you should recognize that chlorine gas is produced instead of oxygen gas in situations where chloride and water are the only reducing agents present.”
  • Electrolytic Cells  Summary:  An electrolytic cell is based upon a reaction that is nonspontaneous; the Eocell for the reaction is negative. An applied voltage of at least the absolute value of E ocell is required to force the reactions to occur.  The SOA undergoes reduction at the cathode (- electrode)  The SRA undergoes oxidation at the anode (+ electrode)  Electrons are forced by a power supply to travel from the anode to the cathode through the external circuit.  Internally, anions move toward the anode and cations move toward the cathode
  • Homework • • Homework Book Pg. 6-7 (Use redox table in textbook pg. 828) Pg. 645 #6-12 • • • Remember molten means liquid state – so there is no water present Don’t forget about the chloride anomaly for one What is coming up tomorrow? • • • • Review on electrolytic and voltaic cells Cell Worksheet #1-6 Start STS Connections Cell Quiz in two days!!
  • Electrochemical Cells Today’s AGENDA: 1.Review Homework 2.Cell Worksheet #1-6 3.Start STS Connections
  • Applications of Electrolytic Cells  Read pg. 646-650  Summary:    In molten-salt electrolysis, metal cations are reduced to metal atoms at the cathode and nonmetal anions are oxidized at the anode. Electrorefining is a process used to obtain high grade metals at the cathode from an impure metal at the anode. Electroplating is a process in which a metal is deposited on the surface of an object placed at the cathode of an electrolytic cell.
  • Homework • Cell Worksheet #1-6 Study for Cell Quiz tomorrow • What is coming up tomorrow? • • • Cell Quiz Finish STS Connections
  • Electrochemical Cells Today’s Objectives: 1.Calculate mass, amounts, current, and time in single voltaic and electrolytic cells by applying Faraday’s law and stoichiometry 2.Predict and write the half-reaction equation that occurs at each electrode in an electrochemical cell
  • Electrochemical Cells Today’s Agenda: 1.Cell Quiz 2.Finish STS Connections
  • Cell Quiz
  • Electrochemical Cells Today’s Agenda: 1.Introduce Cell Stoichiometry
  • Cell Stoichiometry Summary 1. Write the balanced equation for the half-cell reaction of the substance produced or consumed. List the measurements and conversion factors for the given and required entities. 2. Convert the given measurements to an amount in moles by using the appropriate conversion factor. (M, c, F) 3. Calculate the amount of the required substance by using the mole ratio from the half-reaction equation. 4. Convert the calculated amount to the final quantity by using the appropriate conversion factor. (M, c, F)
  • Background  Charge (Q) is determined by multiplying the electric current (I), (measured in C/s) by the time (t) measured is seconds. Q = It (C) = (Ampere)(second) (Coulomb) = (Coulombs per second) x (second) One coulomb is the quantity of charge transferred by a current of 1 Ampere during 1second. Example: Calculate the charge that passes through one 300kA cell in a 24 hour period. Q = It = (300kA x 1000A/kA)(24 h x 3600s/h) = (300000C/s )(86400s) = 2.6 x 1010C
  • Practice: Calculating Charge  Pg. 653 #1-4
  • Faraday’s Law  “The mass of an element produced or consumed at an electrode is directly proportional to the time the cell operated, as long as the current was constant.”  He also found that “9.65 x 104C of charge is transferred for every mole of electrons that flows in the cell. This value is the molar charge of electrons, also called Faraday’s constant” F = 9.65 x 104 C _. mol e-  This constant can by used as a conversion factor in converting electric charge to moles, very similarly to the way that molar mass is used to convert mass to a chemical amount.  I.e. 104 C 2.5 mol x 2.02 g = 5.05 g 15000 C x 1 mol e- = 0.16 mol emol 9.65 x
  • Practice: Faraday’s Law #1  Convert a current of 1.74 A for 10.0 min into an amount of electrons We do not have a direct way of measuring amount of electrons, so we need to calculate charge first (Q = It), and then use Faraday’s constant to calculate the amount of electrons. Q = It = (1.74 C ) (10.0min x 60 s ) = 1044 C x 1 mol = 0.0108 mol s min 9.65 x 104 C You can also write this as a single equation (using cancellation of units):
  • Practice: Faraday’s Law #2  How long, in minutes, will it take a current of 3.50 A to transfer 0.100 mol of electrons? Remember: Amperes = Coulombs/second
  • Practice: Calculating Charge  Pg. 654 #5-7
  • Half Cell Calculations  Since the mass of an element produced at an electrode depends on the amount of transferred electrons (Faraday’s Law), a halfreaction equation showing the number of electrons involved is necessary to do stoichiometric calculations.   This applies to all electrochemical cells, whether voltaic or electrolytic. Separate calculations are carried out for each electrode, although the same charge and therefore the same amount of electrons passes through each electrode in a cell.  Remember: The only new part of the stoichiometry is the calculation involving the amount of electrons based on Faraday’s constant
  • Practice: Half-Cell Calculations #1   What is the mass of copper deposited at the cathode of a copper electrorefining cell operated at 12.0 A for 40.0 min? First identify and write the appropriate half-cell.    Copper is being deposited at the cathode, copper(II) ions must be gaining electrons to form copper metal. Write the equation for this reduction and list all the information given. Do we have enough information to solve for the amount of electrons (moles of electrons)?
  • Practice: Half-Cell Calculations #1  What is the mass of copper deposited at the cathode of a copper electrorefining cell operated at 12.0 A for 40.0 min?  Yes, we can solve for the number of moles, and then use the mole ratio to convert from a chemical amount of one substance to another.  The last step is to convert to the quantity requested in the question, in this case the mass of the copper metal Could we do this as one equation instead? 
  • Practice: Half-Cell Calculations #1  What is the mass of copper deposited at the cathode of a copper electrorefining cell operated at 12.0 A for 40.0 min?
  • Practice: Half-Cell Calculations #2    Silver is deposited on objects in a silver electroplating cell. If 0.175 g of silver is to be deposited from a silver cyanide solution in a time of 10.0 min, predict the current required. Write the balanced equation for the half-cell reaction, list the measurements and conversion factors. Convert to moles, use the mole ratio, convert to the current (C/s)
  • Stoichiometry Calculations (Measured quantity) solids/liquids m gases V, T, P solutions c, V electrochemical cells Q solutions gases solids/liquids (Required quantity) c, V V,T,P m  n mole ratio  n
  • Homework • Homework Book Pg. 8 Pg. 657 #1-8 • What is coming up tomorrow? • • • • Review Cell Stoichiometry Start Chapter 14 Review Electrochemistry Unit Exam coming soon!