Based on the values in the table given below, which of these metals could provid
ID: 857236 • Letter: B
Question
Based on the values in the table given below, which of these metals could provide cathodic protection to iron?
TABLE Standard Reduction Potentials in Water at 25 ?C
Choose all that apply.
E? red (V) Reduction Half-Reaction +2.87 F2(g)+2e??2F?(aq) +1.51 MnO4?(aq)+8H+(aq)+5e??Mn2+(aq)+4H2O(l) +1.36 Cl2(g)+2e??2Cl?(aq) +1.33 Cr2O72?(aq)+14H+(aq)+6e??2Cr3+(aq)+7H2O(l) +1.23 O2(g)+4H+(aq)+4e??2H2O(aq) +1.06 Br2(l)+2e??2Br?(aq) +0.96 NO3?(aq)+4H+(aq)+3e??NO(g)+2H2O(l) +0.80 Ag+(aq)+e??Ag(s) +0.77 Fe3+(aq)+e??Fe2+(aq) +0.68 O2(g)+2H+(aq)+2e??H2O2(aq) +0.59 MnO4?(aq)+2H2O(l)+3e??MnO2(s)+4OH?(aq) +0.54 I2(s)+2e??2I?(aq) +0.40 O2(g)+2H2O(l)+4e??4OH?(aq) +0.34 Cu2+(aq)+2e??Cu(s) 0 [defined] 2H+(aq)+2e??H2(g) -0.28 Ni2+(aq)+2e??Ni(s) -0.44 Fe2+(aq)+2e??Fe(s) -0.76 Zn2+(aq)+2e??Zn(s)Zn2+(aq)+2e??Zn(s) -0.83 2H2O(l)+2e??H2(g)+2OH?(aq) -1.66 Al3+(aq)+3e??Al(s) -2.71 Na+(aq)+e??Na(s) -3.05 Li+(aq)+e??Li(s)Explanation / Answer
Zinc and Aluminum due to both of their reduction half-reactions haveing a lower E0 than the Fe2+(aq) + 2e-