iran-konkur 2013 Q234

iran-konkur · Other · konkur-riazi_1392 Not Maths
234 -- Considering the given standard half-reaction potentials $E^\circ$, which statement is correct?
$$E^\circ[\text{Ni}^{2+}(\text{aq})/\text{Ni}(\text{s})] = -0.25\,\text{V}$$ $$E^\circ[\text{Zn}^{2+}(\text{aq})/\text{Zn}(\text{s})] = -0.76\,\text{V}$$ $$E^\circ[\text{Fe}^{2+}(\text{aq})/\text{Fe}(\text{s})] = -0.44\,\text{V}$$
  1. Under standard conditions, iron reacts with zinc salt solutions.
  2. The reducing power of these three metals is $\text{Ni} > \text{Fe} > \text{Zn}$.
  3. The oxidizing power of the three cations is $\text{Zn}^{2+}(\text{aq}) > \text{Fe}^{2+}(\text{aq}) > \text{Ni}^{2+}(\text{aq})$.
  4. The difference in $E^\circ$ of the iron--nickel electrochemical cell is $0.32$ volts.
\textbf{234 -- Considering the given standard half-reaction potentials $E^\circ$, which statement is correct?}

$$E^\circ[\text{Ni}^{2+}(\text{aq})/\text{Ni}(\text{s})] = -0.25\,\text{V}$$
$$E^\circ[\text{Zn}^{2+}(\text{aq})/\text{Zn}(\text{s})] = -0.76\,\text{V}$$
$$E^\circ[\text{Fe}^{2+}(\text{aq})/\text{Fe}(\text{s})] = -0.44\,\text{V}$$

\begin{enumerate}
\item Under standard conditions, iron reacts with zinc salt solutions.
\item The reducing power of these three metals is $\text{Ni} > \text{Fe} > \text{Zn}$.
\item The oxidizing power of the three cations is $\text{Zn}^{2+}(\text{aq}) > \text{Fe}^{2+}(\text{aq}) > \text{Ni}^{2+}(\text{aq})$.
\item The difference in $E^\circ$ of the iron--nickel electrochemical cell is $0.32$ volts.
\end{enumerate}