12.4 Recorded Macro: Insert the Ideal Gas Constant Record a macro that will insert the ideal gas constant R in the active cell. The value of R depends on the units. Select the value you use most frequently: Ideal Gas Constants 8.314 m³ Pa gmol K 0.08314 L bar gmol K 0.08206 Latm gmol K 0.7302 ft³ atm lbmol °R 10.73 3 psia lbmol °R 8.314 J gmol K 1.987 BTU lbmol °R

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.

For the standard cell potentials given here, determine the ?G for the cell in k].. (a) 0.000V,n=2 (b) +0.434V,n=2 (c) -2.439 V, n = 1

Give the notation for a voltaic cell whose overall cell reaction is Mg(s)+2Ag+(aq)Mg2+(aq)+2Ag(s) What are the half-cell reactions? Label them as anode or cathode reactions. What is the standard cell potential of this cell?

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).

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.

If a logarithmic scale had not been used for the graph of Figure 13.13, what would the plots look like? FIGURE 13.13 The variation of equilibrium constant with cell potential is shown. The different lines correspond to reactions involving the transfer of one, two, or three electrons, as indicated.

Use the data from the table of standard reduction potentials in Appendix H to calculate the standard potential of the cell based on each of the following reactions. In each case, state whether the reaction proceeds spontaneously as written or spontaneously in the reverse direction under standard-state conditions. (a) H2(g)+Cl2(g)2H+(aq)+2Cl(aq) (b) Al3+(aq)+3Cr2+(aq)Al(s)+3Cr3+(aq) (c) Fe2+(aq)+Ag+(aq)Fe3+(aq)+Ag(s)

How does galvanic corrosion differ from uniform corrosion of iron?

Calculate the theoretical potential of each of the following cells.Is the cell reaction spontaneous as written or spontaneous in the opposite direction? (a) Bi|BiO+ (0.0300 M),H+ (0.100 M)||I- (0.100 M), AgI(sat’d)|Ag (b) Zn|Zn2+(5.75 10-4M)||Fe(CN)64-(530 10-2 M),Fe(CN)63-(6.75 10-2M)|Pt (c) Pt,H2O (0.200 atm)|HCI(8.25 10-4M), AgCI(sat’d)| Ag