Example 9. In an electrolysis experiment, a current was passed for 5 hours through two cells connected in series. The first cell contains a solution of gold salt and the second cell contains copper sulphate solution. 9.85 g of gold was deposited in the first cell. If the oxidation number of gold is +3, find the amount of cop- per deposited on the cathode in the second cell. Also, calculate the magnitude of the current in ampere.

Consider a voltaic cell in which the following reaction occurs. Zn(s)+Sn2+(aq)Zn2+(aq)+Sn(s) (a) Calculate E° for the cell. (b) When the cell operates, what happens to the concentration of Zn2+? The concentration of Sn2+? (c) When the cell voltage drops to zero, what is the ratio of the concentration of Zn2+ to that of Sn2+? (d) If the concentration of both cations is 1.0 M originally, what are the concentrations when the voltage drops to zero?

Consider a galvanic cell based on the following half-reactions: a. What is the standard potential for this cell? b. A nonstandard cell is set up at 25C with [Mg2+] = 1.00 105 M. The cell potential is observed to be 4.01 V. Calculate [Au3+] in this cell.

A standard galvanic cell is constructed so that the overall cell reaction is 2A13++(aq)+3M(s)3M2+(aq)+2A1(s) Where M is an unknown metal. If G = 411 kJ for the overall cell reaction, identify the metal used to construct the standard cell.

Consider a voltaic cell in which the following reaction takes place in basic medium at 25°C. 2NO3-(aq)+3S2(aq)+4H2O3S(s)+2NO(g)+8OH(aq) (a) Calculate E°. (b) Write the Nernst equation for the cell E. (c) Calculate E under the following conditions: PNO=0.994atm,ph=13.7,[S2]=0.154M,[NO3-]=0.472M, .

For 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)

A lead storage battery delivers a current of 6.00 A for one hour and 22 minutes at a voltage of 12.0 V. (a) How many grams of lead are converted to PbSO4? (b) How much electrical energy is produced in kilowatt hours?

Consider the electrolysis of water in the presence of very dilute H2SO4. What species is produced at the anode? Atthe cathode? What are the relative amounts of the speciesproduced at the two electrodes?

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.

Consider a concentration cell that has both electrodes made of some metal M. Solution A in one compartment of the cell contains 1.0 M M2+. Solution B in the other cell compartment has a volume of 1.00 L. At the beginning of the experiment 0.0100 mole of M(NO3)2 and 0.0100 mole of Na2SO4 are dissolved in solution B (ignore volume changes), where the reaction M2+(aq)+SO42(aq)MSO4(s) occurs. For this reaction equilibrium is rapidly established, whereupon the cell potential is found to be 0.44 V at 25C. Assume that the process M2++2eM has a standard reduction potential of 0.31 V and that no other redox process occurs in the cell. Calculate the value of Ksp for MSO4(s) at 25C.