Questions: Which species in the table below is the strongest reducing agent? Half-reaction Sn(aq)^(4+) + 2 e^- -> Sn(aq)^(2+) V^(3+)(aq) + e^- -> V(aq)^(2+) Zn(aq)^(2+) + 2 e^- -> Zn(s) I2(s) + 2 e^- -> 2 I(aq)

Transcript text: Which species in the table below is the strongest reducing agent? Half-reaction \[ \begin{array}{l} \mathrm{Sn}_{(\mathrm{aq})}^{4+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Sn}_{(\mathrm{aq})}^{2+} \\ \mathrm{V}^{3+}(\mathrm{aq})+\mathrm{e}^{-} \rightarrow \mathrm{V}_{(\mathrm{aq})}^{2+} \\ \mathrm{Zn}_{(\mathrm{aq})}^{2+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Zn}_{(\mathrm{s})} \\ \mathrm{I}_{2(\mathrm{~s})}+2 \mathrm{e}^{-} \rightarrow 2 \mathrm{r}_{(\mathrm{aq})} \end{array} \]

Solution

Solution Steps

Step 1: Identify the Reducing Agents

A reducing agent is a species that donates electrons in a redox reaction. In the given half-reactions, the reducing agents are the species that are oxidized (lose electrons). These species are:

\(\mathrm{Sn}^{2+}\)
\(\mathrm{V}^{2+}\)
\(\mathrm{Zn}\)
\(\mathrm{I}^{-}\)

Step 2: Determine the Standard Reduction Potentials

To identify the strongest reducing agent, we need to consider the standard reduction potentials (\(E^\circ\)) of the given half-reactions. The species with the most negative reduction potential will be the strongest reducing agent because it is the most willing to lose electrons (be oxidized).

Step 3: Compare the Reduction Potentials

Assuming standard reduction potentials (which are typically provided in tables), we compare the values:

\(\mathrm{Sn}^{4+} + 2 \mathrm{e}^{-} \rightarrow \mathrm{Sn}^{2+}\)
\(\mathrm{V}^{3+} + \mathrm{e}^{-} \rightarrow \mathrm{V}^{2+}\)
\(\mathrm{Zn}^{2+} + 2 \mathrm{e}^{-} \rightarrow \mathrm{Zn}\)
\(\mathrm{I}_{2} + 2 \mathrm{e}^{-} \rightarrow 2 \mathrm{I}^{-}\)

Typically, the standard reduction potential for \(\mathrm{Zn}^{2+} + 2 \mathrm{e}^{-} \rightarrow \mathrm{Zn}\) is around \(-0.76 \, \text{V}\), which is more negative compared to the others.