Concept explainers
In each of the following examples, sketch a voltaic cell that uses the reaction. Label the anode and cathode; indicate the direction of electron flow; write a balanced equation for cell reaction; and calculate
a.
b.
c.
d.
Want to see the full answer?
Check out a sample textbook solutionChapter 19 Solutions
General Chemistry: Principles and Modern Applications (11th Edition)
- Another type of battery is the alkaline zinc-mercury cell, in which the cell reaction is Zn(s) + HgO(s) Hg() + ZnO(s) E = + 1.35 V (a) What is the standard free energy change for this reaction? (b) The standard free energy change in a voltaic cell is the maximum electrical energy that the cell can produce. If the reaction in a zinc-mercury cell consumes 1.00 g mercury oxide, what is the standard free energy change? (c) For how many hours could a mercury cell produce a 10-mA current if the limiting reactant is 3.50 g mercury oxide?arrow_forwardCalculate the standard cell potential of the cell corresponding to the oxidation of oxalic acid, H2C2O4, by permanganate ion. MnO4. 5H2C2O4(aq)+2MnO4(aq)+6H+(aq)10CO2(g)+2Mn2+(aq)+8H2O(l) See Appendix C for free energies of formation: Gf for H2C2O4(aq) is 698 kJ.arrow_forwardConsider the following cell running under standard conditions: Fe(s)Fe2+(aq)Al3+(aq)Al(s) a Is this a voltaic cell? b Which species is being reduced during the chemical reaction? c Which species is the oxidizing agent? d What happens to the concentration of Fe3+(aq) as the reaction proceeds? e How does the mass of Al(s) change as the reaction proceeds?arrow_forward
- You have 1.0 M solutions of Al(NO3)3 and AgNO3 along with Al and Ag electrodes to construct a voltaic cell. The salt bridge contains a saturated solution of KCl. Complete the picture associated with this problem by a writing the symbols of the elements and ions in the appropriate areas (both solutions and electrodes). b identifying the anode and cathode. c indicating the direction of electron flow through the external circuit. d indicating the cell potential (assume standard conditions, with no current flowing). e writing the appropriate half-reaction under each of the containers. f indicating the direction of ion flow in the salt bridge. g identifying the species undergoing oxidation and reduction. h writing the balanced overall reaction for the cell.arrow_forwardWhat mass of each of the following substances can be produced in 1.0 h with a current of 15 A? a. Co from aqueous Co2+ b. Hf from aqueous Hf4+ c. I2 from aqueous KI d. Cr from molten CrO3arrow_forwardIn principle, a battery could be made from aluminum metal and chlorine gas. (a) Write a balanced equation for the reaction thatwould occur in a battery using Al3+(aq) | Al(s) andCl2(g) | Cl(aq) half-cells. (b) Identify the half-reaction at the anode and at the cathode. Do electrons flow from the Al electrode when thecell does work? Explain. (c) Calculate the standard potential, Ecell, for the battery.arrow_forward
- Consider a galvanic cell based on the following half-reactions: a. What is the expected cell potential with all components in their standard states? b. What is the oxidizing agent in the overall cell reaction? c. What substances make up the anode compartment? d. In the standard cell, in which direction do the electrons flow? e. How many electrons are transferred per unit of cell reaction? f. If this cell is set up at 25C with [Fe2+] = 2.00 104 M and [La3+] = 3.00 103 M, what is the expected cell potential?arrow_forwardConsider the following galvanic cell: Calculate the concentrations of Ag+(aq) and Ni2+(aq) once the cell is dead.arrow_forwardAn electrolysis experiment is performed to determine the value of the Faraday constant (number of coulombs per mole of electrons). In this experiment, 28.8 g of gold is plated out from a AuCN solution by running an electrolytic cell for two hours with a current of 2.00 A. What is the experimental value obtained for the Faraday Constant?arrow_forward
- Draw a diagram of each cell. Label the anode, the cathode, the species in each half-cell solution, the direction of electron movement in an external circuit, and thedirection of movement of ions within the cell. (a) Cu(s) | Cu2+(aq) || Fe2+(aq) |Fe(s) (b) Pt(s) | H2O2(aq), H+(aq) || Fe2+(aq), Fe3+(aq) | Pt(s)arrow_forwardIt took 150. s for a current of 1.25 A to plate out 0.109 g of a metal from a solution containing its cations. Show that it is not possible for the cations to have a charge of 1+.arrow_forwardAt 298 K, the solubility product constant for PbC2O4 is 8.5 1010, and the standard reduction potential of the Pb2+(aq) to Pb(s) is 0.126 V. (a) Find the standard potential of the half-reaction PbC2O4(s)+2ePb(s)+C2O42(aq) (Hint: The desired half-reaction is the sum of the equations for the solubility product and the reduction of Pb2+. Find G for these two reactions and add them to find G for their sum. Convert the G to the potential of the desired half-reaction.) (b) Calculate the potential of the Pb/PbC2O4 electrode in a 0.025 M solution of Na2C2O4.arrow_forward
- Chemistry: An Atoms First ApproachChemistryISBN:9781305079243Author:Steven S. Zumdahl, Susan A. ZumdahlPublisher:Cengage LearningChemistryChemistryISBN:9781305957404Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCostePublisher:Cengage Learning
- Chemistry: The Molecular ScienceChemistryISBN:9781285199047Author:John W. Moore, Conrad L. StanitskiPublisher:Cengage LearningGeneral Chemistry - Standalone book (MindTap Cour...ChemistryISBN:9781305580343Author:Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; DarrellPublisher:Cengage Learning