Statement I: A metal having negative reduction potential when dipped in the solution of its own ions — Electrochemistry Chemistry Question

💡 Solution & Explanation

\textbf{Assertion (I):} Metals with negative standard electrode (reduction) potential dissolve in acids to produce hydrogen gas. \textbf{Reason (II):} Such metals have a tendency to lose electrons. \textbf{Analysis:} \textbf{Statement I:} For a metal M to dissolve in acid and produce H\textsubscript{2}: \[ \text{M} + 2\text{H}^+ \rightarrow \text{M}^{2+} + \text{H}_2 \] For this reaction to be spontaneous, E\textdegree\textsubscript{cell} > 0: \[ E^\circ_{\text{cell}} = E^\circ_{\text{cathode}} - E^\circ_{\text{anode}} = 0 - E^\circ_{\text{M}} > 0 \] This requires $E^\circ_{\text{M}} < 0$, i.e., the metal must have a \textit{negative} standard reduction potential. ✓ \textbf{Statement I is correct.} \textbf{Statement II:} All metals (including those with positive E\textdegree like Cu, Ag, Au) have a tendency to lose electrons — this is a general property of metals. So Statement II does not uniquely explain why only negative-E\textdegree metals dissolve in acid. ✗ \textbf{Statement II is incorrect} as an explanation (too broad; doesn't distinguish reactive from noble metals). \textbf{Answer: B} (Statement I correct, Statement II incorrect)