Four successive members of the first row of transition elements are listed below with atomic numbers. Which one of them is expected to have the highest E M 3 + / M 2 + o value?

Question

Aicharya · Accepted Answer

Species having the highest reduction potential i.e., tendency to undergo reduction by gain of electron. SRP value increases from left to right in the period for the d-block elements.

M^{3 +} (a q) + 1 e^{-} \to M^{2 +} (a q)

\begin{matrix} _{26} {Fe}^{3 +} / {Fe}^{2 +} \Rightarrow & 4 s^{0} 3 d^{5} \to 4 s^{0} 3 d^{6} & (+ 0.77 volt) \\ _{27} {Co}^{3 +} / {Co}^{2 +} \Rightarrow & 4 s^{0} 3 d^{6} \to 4 s^{0} 3 d^{7} & (+ 1.97 volt) \\ _{24} {Cr}^{3 +} / {Cr}^{2 +} & 4 s^{0} 3 d^{3} \to 4 s^{0} 3 d^{4} & (- 0.4 volt) \\ _{25} {Mn}^{3 +} / {Mn}^{2 +} & 4 s^{0} 3 d^{4} \to 4 s^{0} 3 d^{5} & (+ 1.57 volt) \end{matrix}

Highest reduction potential means strong oxidising agent, i.e. undergoing reduction

{Co}^{3 +} + 1 e^{-} \to {Co}^{2 +}

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Four successive members of the first row of transition elements are listed below with atomic numbers. Which…

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