Construct a galvanic cell with a voltage of+0.87 V at 298 K using Cu and Ni meta
ID: 491472 • Letter: C
Question
Construct a galvanic cell with a voltage of+0.87 V at 298 K using Cu and Ni metal electrodes ami using the following half-reactions. E= -0.23 V E = +0.52 V Indicate whether Zn, Cu. or both would inhibit corrosion of iron by attachment to an iron structure. Assume standard conditions are in place. Give your reasoning. Relevant standard potentials arc: E = -0.44 V E = .0.76 V E = +0.34 V Determine the standard cell potential and the Delta G" of an electrochemical cell using the two follow mg half reactions running in the direction in which nitrate (NO_3) is consumed. E" = +0.96 V E' = +1.00V Construct a galvanic cell using copper and silver electrodes and the following halt reactions. Provide the AT for the cell running as a galvanic cell. Indicate the cathode and anode. Now. replace the cathode in the above cell with Ni and answer the above questions a) and b). Note the relevant reduction potential for the Ni electrode is: F - -0.23 V From the following information, determine the formation constant K, for the complex ion [Fe(CN)_e)]^3. where the formation constant K_f is defined as the equilibrium constant for the following reaction: (note that the Fe is in the Fe^3+ oxidation state in (Fe(CN)_6]^3). Relevant information: the equilibrium formation constant F_f for [Fe(CN)6]^4+ is 1.0 times 10^24 (note that the Fe is in the Fe^2+' oxidation state in [Fe(CN)_6]^4)Explanation / Answer
Cu^2+/Cu has a greater reduction potential value than Ni^2+/Ni. So, Cu^2+/Cu will act as a cathode and Ni^2+/Ni will act as anode.
Ni/Ni^2+ II Cu^2+/Cu
E(cell) = 0.52 - (0.23) = 0.75 V
Anodic reaction : Ni (s)----> Ni ^2+ + 2e-
Cathodic reaction : Cu ^2+ + 2e- ----> Cu(s)
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Net reaction : Ni (s) + Cu ^2+ -------> Ni ^2+ + Cu(s)
E(cell) = E^0 - 0.059/2 ln[Ni^2+/Cu^2+]
0.87 = 0.75 - 0.059/2 ln[Ni^2+/Cu^2+]
or, ln[Ni^2+/Cu^2+] = -4.067
or, [Ni^2+/Cu^2+] = 0.017
So, the cell should be such that the concentration ratio is 0.017