Which metal is most easily oxidized? A) Cu B) Ag C) Mg D) Co
The Correct Answer and Explanation is:
The correct answer is C) Mg (Magnesium).
To determine which metal is most easily oxidized, we can look at the metals’ standard reduction potentials. Oxidation is the loss of electrons, and the more easily a metal loses electrons, the more easily it is oxidized. The standard reduction potential gives us a way to predict this behavior. The more negative the standard reduction potential, the easier the metal is to oxidize.
Here are the standard reduction potentials (in volts) for the metals listed:
- Cu (Copper): +0.34 V
- Ag (Silver): +0.80 V
- Mg (Magnesium): -2.37 V
- Co (Cobalt): -0.28 V
Since the standard reduction potential is negative for oxidation reactions, the metal with the most negative reduction potential is the one that is most easily oxidized. In this case, magnesium has the most negative reduction potential, indicating that it is the easiest to oxidize.
Explanation:
When a metal undergoes oxidation, it loses electrons. The process of oxidation occurs when a metal is exposed to an oxidizing agent (like oxygen in the air), and the metal atoms lose electrons, forming positive ions. The metal’s tendency to lose electrons is related to its position on the electrochemical series, which is based on its standard electrode potential.
- Magnesium has a very low (negative) reduction potential, meaning it is highly reactive and readily gives up electrons. It’s often used in applications where its ability to oxidize (and thus corrode) is taken into account, like in sacrificial anodes used to protect ships or pipelines.
- Copper, on the other hand, has a higher (positive) reduction potential, meaning it is less easily oxidized compared to magnesium. This is why copper, for example, does not corrode as easily as magnesium.
Therefore, magnesium is the most easily oxidized metal in this list.
