Which of the following species will be oxidized by \(1 \mathrm{MHCl}\) ? (a) \(\mathrm{Au}\) (b) \(\mathrm{Mg}\) (c) Cu (d) \(\mathrm{F}^{-}\)

First, determine the oxidation potential of H+. The standard oxidation potential of H+ in the reaction is given as: $$ 2\mathrm{H}^+ + 2\mathrm{e}^- \rightleftharpoons\mathrm{H}_{2} $$ Since the standard reduction potential of this reaction (reverse of the reaction) can be easily found in a table of standard reduction potentials, it has the value of \(0 \mathrm{V}\). The standard oxidation potential of H+ will be the negative of this value, which is also \(0\mathrm{V}\).

Now, look up the standard oxidation potentials of the given species (Au, Mg, Cu, and F-). In any standard reduction potential table, you can find the reduction potentials of these species' respective half-cell reactions and switch their signs to get the oxidation potentials. The species with the highest oxidation potential will have the greatest tendency to lose electrons and be oxidized. Here are the oxidation potentials of the given species: - Au: \(1.50\mathrm{V}\) - Mg: \(-2.37\mathrm{V}\) - Cu: \(0.34\mathrm{V}\) - F-: \(2.87\mathrm{V}\)

Compare the oxidation potentials of the given species to the oxidation potential of H+. If a species has a higher oxidation potential than H+, it will have a greater tendency to lose electrons and be oxidized. - Au (\(1.50\mathrm{V}\)) has a higher oxidation potential than H+ (\(0\mathrm{V}\)), meaning it is less likely to be oxidized than H+. - Mg (\(-2.37\mathrm{V}\)) has a lower oxidation potential than H+ (\(0\mathrm{V}\)), meaning it is more likely to be oxidized than H+. - Cu (\(0.34\mathrm{V}\)) has a higher oxidation potential than H+ (\(0\mathrm{V}\)), meaning it is less likely to be oxidized than H+. - F- (\(2.87\mathrm{V}\)) has a higher oxidation potential than H+ (\(0\mathrm{V}\)), meaning it is less likely to be oxidized than H+.

After comparing the oxidation potentials of the given species, we find that Mg has the lowest oxidation potential, meaning it is most likely to lose electrons and be oxidized by 1M HCl. Therefore, the answer is (b) Mg.