Concept explainers
A concentration cell has different concentrations of the same ions, but because of the different concentrations there is a very small voltage between the cells. This effect is especially problematic for corrosion. Consider the following overall reaction, which is assumed to occur in the presence of metallic iron:
(a) What is
(b) What is the expression for Q?
(c) What is
(d) Should concentration cells be considered another type of colligative property? Explain your answer.
Want to see the full answer?
Check out a sample textbook solutionChapter 8 Solutions
Student Solutions Manual for Ball's Physical Chemistry, 2nd
- For the reaction Cu2+(aq) + Zn(s) → Cu(s) + Zn2+ (aq), why can’t you generate electric current by placing a piece of copper metal and a piece of zinc metal in a solution containing CuCl2(aq) and ZnCl2(aq)?arrow_forwardThe standard potential, E, for the reaction of Zn(s) and Cl2(g) is +2.12 V. What is the standard free energy change, rG, for the reaction?arrow_forwardWhat is the standard cell potential you would obtain from a cell at 25C using an electrode in which Hg22+(aq) is in contact with mercury metal and an electrode in which an aluminum strip dips into a solution of Al3+(aq)?arrow_forward
- The mass of three different metal electrodes, each from a different galvanic cell, were determined before and after the current generated by the oxidation-reduction reaction in each cell was allowed to flow for a few minutes. The first metal electrode, given the label A, was found to have increased in mass; the second metal electrode, given the label B, did not change in mass; and the third metal electrode, given the label C, was found to have lost mass. Make an educated guess as to which electrodes were active and which were inert electrodes, and which were anode(s) and which were the cathode(s).arrow_forwardFor each reaction listed, determine its standard cell potential at 25 C and whether the reaction is spontaneous at standard conditions. (a) Mn(s)+Ni2+(aq)Mn2+(aq)+Ni(s) (b) 3Cu2+(aq)+2Al(s)2Al3+(aq)+3Cu(s) (c) Na(s)+LiNO3(aq)NaNO3(aq)+Li(s) (d) Ca(NO3)2(aq)+Ba(s)Ba(NO3)2(aq)+Ca(s)arrow_forwarda Calculate G for the following cell reaction: Tl(s)Tl+(aq)Pb2+(aq)Pb(s) The Gf for Tl+(aq) is 32.4 kJ/mol. b From G, calculate the standard cell potential for the cell reaction and from this, determine the standard potential for Tl2+(aq)+eTl(s).arrow_forward
- Consider 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_forwardCalcium metal can be obtained by the direct electrolysis of molten CaCl2, at a voltage of 3.2 V. (a) How many joules of electrical energy are required to obtain 12.0 1b of calcium? (b) What is the cost of the electrical energy obtained in (a) if electrical energy is sold at the rate of nine cents per kilowatt hour?arrow_forwardChlorine, Cl2, is produced commercially by the electrolysis of aqueous sodium chloride. The anode reaction is 2Cl(aq)Cl2(g)+2e How long will it take to produce 2.00 kg of chlorine if the current is 5.00 102 A?arrow_forward
- 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_forwardYou 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_forwardA solution contains the ions H+, Ag+, Pb2+, and Ba2+, each at a concentration of 1.0 M. (a) Which of these ions would be reduced first at the cathode during an electrolysis? (b) After the first ion has been completely removed by electrolysis, which is the second ion to be reduced? (c) Which, if any, of these ions cannot be reduced by the electrolysis of the aqueous solution?arrow_forward
- General 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 LearningIntroductory Chemistry: A FoundationChemistryISBN:9781337399425Author:Steven S. Zumdahl, Donald J. DeCostePublisher:Cengage LearningChemistry: Principles and PracticeChemistryISBN:9780534420123Author:Daniel L. Reger, Scott R. Goode, David W. Ball, Edward MercerPublisher:Cengage Learning
- Principles of Modern ChemistryChemistryISBN:9781305079113Author:David W. Oxtoby, H. Pat Gillis, Laurie J. ButlerPublisher:Cengage LearningChemistry: Principles and ReactionsChemistryISBN:9781305079373Author:William L. Masterton, Cecile N. HurleyPublisher:Cengage LearningChemistry: The Molecular ScienceChemistryISBN:9781285199047Author:John W. Moore, Conrad L. StanitskiPublisher:Cengage Learning