COMEDK · Chemistry · 23. d and f Block Elements
Two statements, one Assertion and the other Reason, are given. Choose the right option.
Assertion: The Standard Electrode potential, \(\mathrm{E}^0 \mathrm{Co}^{3+} / \mathrm{Co}^{2+}\) is greater than \(\mathrm{E}^0 \mathrm{Fe}^{3+} / \mathrm{Fe}^{2+}\).
Reason: \(\mathrm{Co}^{3+}\) ions are less stable in aqueous medium than \(\mathrm{Fe}^{3+}\) ions which has stable \(\mathrm{d}^5\) configuration
- A Assertion is correct but Reason is incorrect.
- B Both Assertion and Reason are correct but Reason is not the correct explanation of Assertion.
- C Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
- D Assertion is incorrect but Reason is correct.
Answer & Solution
Correct Answer
(C) Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
Step-by-step Solution
Detailed explanation
The standard electrode potential \(E^{0}\) for the reduction \(M^{3+} + e^{-} \rightarrow M^{2+}\) depends on the stability of the \(M^{3+}\) and \(M^{2+}\) oxidation states in aqueous solution. For iron, the \(Fe^{3+}\) ion has a stable \(d^{5}\) configuration, making it…
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