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Calculate the potential of the following cell `:` `Pt|underset((2.0M)(1.0M))(Co^(2+),Co^(3+))|underset((1.0M)(4.0M)(1.0M))(Cr^(3+),Cr_(2)O_(7)^(2_-),H^(o+))|Pt` `E^(c-)._(Co^(2+)|Co^(3+))=-2V,E^(c-)._(Cr_(2)O_(7)^(2-)|Cr^(3+))=+1.0V`A. `1.024V`B. `-1.024V`C. `0.976V`D. `-0.976V` |
Answer» Correct Answer - d `Co^(2+) rarr Co^(3+)+e^(-)]xx6` `14H^(o+)+6e^(-)+Cr_(2)O_(7)^(2-)rarr2Cr^(3+)+7H_(2)O` `ulbar(6Co^(2+)+14H^(o+)+Cr_(2)O_(7)^(2-)rarr6Co^(3+)+2Cr^(3+)+7H_(2)O)` `E^(c-)._(cell)=E^(c-)._(c)-E^(c-)._(a)(E^(c-)._(red)Co^(3+)|Co^(2+)=2V)` `=1-2=-1V` `E=E^(c-)-(0.059)/(6)log.([Co^(3+)]^(6)[Cr^(3+)]^(2))/([Co^(2+)]^(6)[H^(o+)]^(14)[Cr_(2)O_(7)^(2-)])` `=-1-0.01log.((1)^(6)xx(1)^(2))/((2)^(6)xx(1)^(14)xx(4))` `=-1-0.01log(2)^(-8)` `=-1+0.01xx8xx0.3` `=-0.976V` |
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