The standard reduction potentials at $298 \, \mathrm{K}$ for the following half cells are given below :…
The standard reduction potentials at $298 \, \mathrm{K}$ for the following half cells are given below :
$\begin{aligned}
\mathrm{Cr}_2 \mathrm{O}_7^{2-}+14 \mathrm{H}^{+}+6 \mathrm{e}^{-} &\rightarrow 2 \mathrm{Cr}^{3+}+7 \mathrm{H}_2 \mathrm{O}, &\mathrm{E}^{\circ}&=1.33 \, \mathrm{V} \\
\mathrm{Fe}^{3+}(\mathrm{aq})+3 \mathrm{e}^{-} &\rightarrow \mathrm{Fe}, &\mathrm{E}^{\circ}&=-0.04 \, \mathrm{V} \\
\mathrm{Ni}^{2+}(\mathrm{aq})+2 \mathrm{e}^{-} &\rightarrow \mathrm{Ni}, &\mathrm{E}^{\circ}&=-0.25 \, \mathrm{V} \\
\mathrm{Ag}^{+}(\mathrm{aq})+\mathrm{e}^{-} &\rightarrow \mathrm{Ag}, &\mathrm{E}^{\circ}&=0.80 \, \mathrm{V} \\
\mathrm{Au}^{3+}(\mathrm{aq})+3 \mathrm{e}^{-} &\rightarrow \mathrm{Au}, &\mathrm{E}^{\circ}&=1.40 \, \mathrm{V}
\end{aligned}$
Consider the given electrochemical reactions,
The number of metal(s) which will be oxidized by $\mathrm{Cr}_2 \mathrm{O}_7^{2-}$, in aqueous solution is ______
Solution
$\mathrm{Fe}, \mathrm{Ni}, \mathrm{Ag}$ will be oxidized due to lower S.R.P.