\(Cr_2O_7^{2–} + I^– \rightarrow I_2 + Cr^{3+}\), \(E^o_{cell} = 0.79 V\), \(E^o_{Cr_2O_7^{–2}|Cr^{+3}} = 1.33 V\), \(E^o_{I_2| I^-}= ?\)
Answer & explanation
Correct answer: option 1
The correct answer is option 1. 0.54.
To find the standard electrode potential (\(E^o_{I_2| I^-}\)) for the reaction \(I_2 + 2I^- \rightarrow 2I^-\), we can use the Nernst equation:
\(E^o_{cell} = E^o_{Cr_2O_7^{2-}|Cr^{3+}} - E^o_{I_2| I^-}\)
Given that \(E^o_{cell} = 0.79 V\) and \(E^o_{Cr_2O_7^{2-}|Cr^{3+}} = 1.33 V\), we can rearrange the equation to solve for \(E^o_{I_2| I^-}\):
\(E^o_{I_2| I^-} = E^o_{Cr_2O_7^{2-}|Cr^{3+}} - E^o_{cell}\)
\(E^o_{I_2| I^-} = 1.33 V - 0.79 V\)
\(E^o_{I_2| I^-} = 0.54 V\)
Therefore, the correct answer is (1) 0.54 V.