Question 14.25 (Sixth Edition)

[Steve Magana 2I]

Question: Arrange the following metals in order of increasing strength as reducing agents for species in aqueous solution: (a) Cu, Zn, Cr, Fe; (b) Li, Na, K, Mg; (c) U, V, Ti, Al; (d) Ni, Sn, Au, Ag.

How does one determine the strength of each element in these cases? Thank you!

[Elisa Bass 4L]

Remember that a metal having a more negative (or less positive) reduction potential means it is a stronger reducing agent (which means it is the species that is doing the reducing). For the first part of the problem, all the metals except Cu have negative reduction potentials, so compare those values with Cu having the lowest strength as a reduction agent.

[Jordan Lo 2A]

A greater E on the standard reduction potential list means reduction is more favorable. For example, Lithium is a metal that likes to "give away" its electron so reducing it (adding an electron) is very unfavorable and E is very negative. When E is negative, the reverse reaction is more favorable

[Aarti K Jain 1L]

The more negative the standard potential, the more strongly the reducing agent/element.