- Paction Direction Half Cell Electrode Ered Relative To Cu2 V Anode Half Cell Cathode Half Cell Overall Spontaneous Re 1 (211.65 KiB) Viewed 27 times
Paction Direction Half-cell electrode Ered relative to Cu2+ (V) Anode half-cell Cathode half-cell Overall spontaneous redox rxn between the half-cells. (anode half-cell = oxidation, cathode half-cell = reduction) Ecell (V) Ag Pb Zn / 0.403 C2% 4,743 344 lines) >60+( np. -0.475 | PHY/Pb (t/ou plis & Chit pbt 19) + Cuis) -0.899 h/24 (ah/a 2nes) + a g) option) + Cuts AL -0.530 AB/A G/lu 2016) + 3cu haf) 2 A13t, a) + 3 lul) -1540 N14 Callu ng is) + Cal 99 ht ca) + Cues) Referring Table I, if you were to place the black probe of the voltmeter on the silver electrode and the red probe on the 10.40 10.45 0.899 0330 1154 1 Mg 1. Zinc electrode: a) What voltage would the voltmeter read? b) Which electrode would act as the anode? 1.30 c) Write the overall spontaneous redox reaction that would occur: 24gT+2n > 2490 + 212*108) Use your Ered values relative to Cu to make a list of relative reduction potentials for the measured half-cells. Include Cuin the list. List the most positive half-cell reduction potential at the top of Table II, the least positive on the bottom. Write the corresponding REDUCTION half-rxn for each half-cell. Convert your half-cell voltages (relative to Cu?) to voltages relative to the standard hydrogen electrode. Finally, report the literature standard reduction potential for each metal. Table II. Experimental Reduction Half-reaction Voltages. Ehalf-rxn (V) Ehalf-rxn (V) Literature Reduction half-reaction (measured in lab relative to the SHE relative to Cu2+) (add 0.34 V) Ered (V) get on the - Mg(s) IS -120 - 237 zu 2tal) the 2n) -0.589 -0.76 413t les thé - Ho - 010 -0.19 -1.66 pot cay) then pb (s) -0.135 An by the la 034 0.3 At te » As) 0_433 0743 2. Based on Table II: a) What metal is the strongest reducing agent? ng b) What ion is the strongest oxidizing agent? Дg 3. For two of the metals, you should have observed that the voltage measurements were difficult to obtain because the voltage reading was not stable. For these two metals, your results are likely to be relatively inaccurate. Identify the two metals that behaved this way and explain clearly and completely explain why they do so. (Hint: Think about the ease with which these two metals are oxidized, the reduction of water and what is formed on the surface of these metals when immersed in water or exposed to the atmosphere.) -0.12