Understanding Electron Releasing Tendency of Metals

The electron releasing tendency of a metal refers to its ability to lose electrons and form positive ions. Metals that readily lose electrons are considered more reactive and have a higher electron releasing tendency. This property is directly related to the metal's standard electrode potential or its position in the electrochemical series, also known as the reactivity series.

In the electrochemical series, metals are arranged in order of their standard electrode potentials. Metals placed higher in the series have a greater tendency to lose electrons (get oxidized) compared to those placed lower. This means they are stronger reducing agents.

Let's consider the position of Zinc (Zn), Copper (Cu), and Silver (Ag) in the standard electrochemical series:

• Zinc (Zn) is relatively high in the series.
• Copper (Cu) is below Zinc.
• Silver (Ag) is below Copper.

Based on their positions, the order of their tendency to lose electrons (electron releasing tendency) is:

Zn > Cu > Ag

This order indicates that Zinc has a higher tendency to lose electrons than Copper, and Copper has a higher tendency to lose electrons than Silver. Therefore, Zinc is more reactive than Copper, and Copper is more reactive than Silver.

Comparing Options for Correct Electron Releasing Tendency Order

We need to find the option that correctly represents the order Zn > Cu > Ag.

• Option 1: Zn > Cu > Ag
• Option 2: Ag > Cu > Zn
• Option 3: Cu > Zn > Ag
• Option 4: Cu > Ag > Zn

Comparing the order derived from the electrochemical series (Zn > Cu > Ag) with the given options, we see that Option 1 matches the correct order.

Conclusion: Electron Releasing Tendency Order

The correct order of electron releasing tendency for Zinc, Copper, and Silver is determined by their positions in the reactivity or electrochemical series. Metals higher in the series are more easily oxidized and have a greater electron releasing tendency.

The relative positions are Zn > Cu > Ag in terms of reactivity and electron releasing tendency.

Revision Table: Key Concepts

Additional Information: Electrochemical Series Details

The electrochemical series provides a quantitative measure of the relative tendencies of different species to gain or lose electrons. This is represented by standard electrode potentials (E°).

• A more negative (or less positive) standard electrode potential for the reduction of a metal ion indicates that the metal itself has a greater tendency to be oxidized (lose electrons).
• Conversely, a more positive (or less negative) standard electrode potential indicates that the metal ion has a greater tendency to be reduced (gain electrons), meaning the metal itself has a lower tendency to lose electrons.

For the metals in question, approximate standard electrode potentials for reduction are:

• Zn$^{2+}$(aq) + 2e$^-$ → Zn(s)   E° ≈ -0.76 V
• Cu$^{2+}$(aq) + 2e$^-$ → Cu(s)    E° ≈ +0.34 V
• Ag$^{+}$(aq) + e$^-$ → Ag(s)    E° ≈ +0.80 V

A lower (more negative) E° value for reduction corresponds to a higher tendency for the reverse reaction (oxidation), which is the electron releasing tendency of the metal. Comparing the E° values (-0.76 V, +0.34 V, +0.80 V), we see that -0.76 V (for Zn) is the lowest, followed by +0.34 V (for Cu), and then +0.80 V (for Ag) is the highest. This confirms the order of electron releasing tendency as Zn > Cu > Ag.