The $E^{\ominus}$ values for $\begin{aligned} & \mathrm{Al}^{+} / \mathrm{Al}=+0.55 \mathrm{~V} \text { and…

The $E^{\ominus}$ values for $\begin{aligned} & \mathrm{Al}^{+} / \mathrm{Al}=+0.55 \mathrm{~V} \text { and } \mathrm{Tl}^{+} / \mathrm{TI}=-0.34 \mathrm{~V} \\ & \mathrm{Al}^{3+} / \mathrm{Al}=-1.66 \mathrm{~V} \text { and } \mathrm{Tl}^{3+} / \mathrm{TI}=+1.26 \mathrm{~V}\end{aligned}$ Identify the incorrect statement.
  1. $\mathrm{Al}^{+}$is unstable in solution.
  2. $\mathrm{TI}$ can be easily oxidised to $\mathrm{Tl}^{+}$than $\mathrm{Tl}^{3+}$.
  3. $\mathrm{Al}$ is more electropositive than $\mathrm{TI}$.
  4. $\mathrm{Tl}^{3+}$ is a good reducing agent than $\mathrm{Tl}^{1+}$.

Solution

(1) $\mathrm{Al}^{+}$is unstable in solution because $\mathrm{SRP}$ of $\mathrm{Al}^{+} / \mathrm{Al}$ is positive hence, it will get reduced in solution. (2) $\begin{array}{ll}\mathrm{Tl} / \mathrm{Tl}^{+}=+0.34 & (\mathrm{SOP}) \\ \mathrm{Tl} / \mathrm{Tl}^{3+}=-1.26 & (\mathrm{SOP})\end{array}$ Since, SOP TI/TI $>$ TI/T1 ${ }^{+}$ Hence, $\mathrm{TI}$ will get oxidised to $\mathrm{Tl}^{+}$easily than $\mathrm{Tl}^{3+}$ (3) Since $\mathrm{Al}^2 / \mathrm{Al}^{3+}$ has more SOP than $\mathrm{Tl} / \mathrm{Tl}^{+}$it will be more electropositive (4) Since $\begin{aligned} \mathrm{Tl}^{3+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Tl}^{+} ; \mathrm{E}=\frac{3 \times 1.26+0.34}{2} \\ =+2.04\end{aligned}$ Hence, $\mathrm{Tl}^{3+}$ is better oxidising agent not reducing agent

Asked in: NEET 2023 (Manipur)

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