By using the data in Appendix E, determine whether each of the following substances is likely to serve as an oxidant or a reductant: (a) \(\mathrm{Cl}_{2}(g),(\mathbf{b}) \mathrm{MnO}_{4}^{-}(a q,\) acidic solution), (c) \(\mathrm{Ba}(s),(\mathbf{d}) \mathrm{Zn}(s) .\)

Consult Appendix E to find the standard reduction potential values (\(E^\circ\)) for each substance. Look for the half-reactions that directly involve the given substances. (a) For \(\mathrm{Cl}_{2}(g)\), find the half-reaction: \(\mathrm{Cl}_{2}(g)+2e^{-}\rightarrow 2 \mathrm{Cl}^{-}(a q)\). The \(E^\circ\) value for this half-reaction is 1.36 V. (b) For \(\mathrm{MnO}_{4}^{-}(a q, \text {acidic solution})\), find the half-reaction: \(\mathrm{MnO}_{4}^{-}+8 \mathrm{H}^{+}+5 e^{-}\rightarrow \mathrm{Mn}^{2+}+4 \mathrm{H}_{2} \mathrm{O}\). The \(E^\circ\) value for this half-reaction is 1.51 V. (c) For \(\mathrm{Ba}(s)\), find the half-reaction: \(\mathrm{Ba}^{2+}+2 e^{-}\rightarrow \mathrm{Ba}(s)\). The \(E^\circ\) value for this half-reaction is -2.92 V. (d) For \(\mathrm{Zn}(s)\), find the half-reaction: \(\mathrm{Zn}^{2+}+2 e^{-}\rightarrow \mathrm{Zn}(s)\). The \(E^\circ\) value for this half-reaction is -0.76 V.

A substance will act as an oxidant if its reduction potential is high, indicating that it has a high tendency to gain electrons (undergo reduction). Conversely, a substance will act as a reductant if its reduction potential is low, indicating that it has a high tendency to lose electrons (undergo oxidation). (a) \(\mathrm{Cl}_{2}(g)\): Since the reduction potential is 1.36 V, a high positive value, \(\mathrm{Cl}_{2}(g)\) is likely to act as an oxidant. (b) \(\mathrm{MnO}_{4}^{-}(a q, \text {acidic solution})\): Since the reduction potential is 1.51 V, another high positive value, \(\mathrm{MnO}_{4}^{-}\) is also likely to act as an oxidant. (c) \(\mathrm{Ba}(s)\): With a reduction potential of -2.92 V, a low negative value, \(\mathrm{Ba}(s)\) is likely to act as a reductant. (d) \(\mathrm{Zn}(s)\): The reduction potential of -0.76 V, another low negative value, indicates that \(\mathrm{Zn}(s)\) is likely to act as a reductant.

Based on the data in Appendix E, the substances will likely act as oxidants or reductants as follows: (a) \(\mathrm{Cl}_{2}(g)\) - Oxidant (b) \(\mathrm{MnO}_{4}^{-}(a q, \text {acidic solution})\) - Oxidant (c) \(\mathrm{Ba}(s)\) - Reductant (d) \(\mathrm{Zn}(s)\) - Reductant