Which metal has the least tendency to be oxidized? (a) Sn (b) \(\mathrm{Mg}\) (c) Cu (d) \(\mathrm{Fe}\)

Understanding the concept of standard reduction potentials is crucial in predicting the tendency of a substance to gain electrons, a process known as reduction. In the context of determining which metal is least likely to be oxidized, these potentials serve as a roadmap.

Each element's standard reduction potential is measured relative to the standard hydrogen electrode, which is set at zero volts. The higher the positive value of the standard reduction potential, the stronger the attraction of the element for electrons. This indicates that the substance is less likely to lose electrons (or be oxidized) and more likely to gain them. Conversely, a lower or more negative potential suggests a greater tendency to lose electrons.

If we have a series of metals and their standard reduction potentials, we can quickly rank them according to their likelihood to be oxidized. This enables us to predict their behavior in electrochemical cells and reactions. For instance, a high standard reduction potential signifies a lower reactivity and a lower tendency to be oxidized, making these metals better candidates for use in conditions where corrosion resistance is desired.

Oxidation and reduction are two halves of the same chemical process known as a redox reaction. Oxidation refers to the loss of electrons, while reduction is the gain of electrons. It is easy to remember this with the simple mnemonic 'OIL RIG': Oxidation Is Loss, Reduction Is Gain.

The concept of oxidation originally involved oxygen reactions, where metals would give up electrons to oxygen and form oxides. However, the definition expanded to cover a broader range of reactions where any form of electron loss occurs. In a redox process, one substance is oxidized (loses electrons) and another is reduced (gains electrons).

In the context of your textbook exercise, metals that have the least tendency to be oxidized will hold onto their electrons more tenaciously. As a result, they do not react as easily with oxidizing agents. This concept is integral in applications such as preventing rust on iron or manufacturing batteries, where specific metals are chosen based on their oxidation tendencies.

Metal reactivity is a measure of how readily a metal will undergo chemical reactions, particularly how it loses electrons to form positive ions (cations). This reactivity series governs a wide array of practical applications, such as material selection for construction or the development of chemical catalysts.

The tendency of a metal to be oxidized is linked to its position in the reactivity series. Metals like potassium and magnesium are placed high on this series, indicating they are very reactive and have a high tendency to be oxidized. On the other hand, metals like gold and platinum are found at the bottom of the series, showing their resistance to oxidation.

Understanding metal reactivity not only helps us in predictive chemistry for reactions but also plays a significant role in industrial processes. For example, reactive metals can be used in energy storage systems like batteries, while less reactive metals are sought after in jewelry making due to their luster and resistance to tarnish.