The 3d series element with positive SRP ( ${\mathrm{M}}^{2+}/\mathrm{M}$ ) is

In this detailed analysis, we will explore the concept of standard reduction potential (SRP) for the 3d series elements. Specifically, we will identify which element from the 3d series has a positive SRP, focusing on the half-reaction involving the reduction of metal ions to metals.

Step 1: Identifying the 3d-Series Elements

The 3d series refers to the elements in the periodic table with partially filled d-orbitals. These elements span from Scandium (Sc) to Zinc (Zn). The 3d-series elements include:

• Scandium (Sc)
• Titanium (Ti)
• Vanadium (V)
• Chromium (Cr)
• Manganese (Mn)
• Iron (Fe)
• Cobalt (Co)
• Nickel (Ni)
• Copper (Cu)
• Zinc (Zn)

Step 2: Understanding Electrode Potential

The electrode potential of a substance refers to its ability to gain or lose electrons in a half-reaction. The more positive the electrode potential, the more likely it is to gain electrons and undergo reduction. A positive SRP indicates a stronger tendency for the element to be reduced from its ion to its metallic state, whereas a negative SRP indicates a lesser tendency to gain electrons.

Step 3: Referencing the Electrochemical Series

The electrochemical series lists the standard electrode potentials (SRPs) for various half-reactions. We can use this series to analyze the 3d series elements and their respective SRPs for the half-reaction:

        M2+ + 2e- → M (Metallic state)
    

Step 4: Standard Electrode Potentials for 3d-Series Elements

Here are the approximate standard electrode potentials for the 3d-series elements:

• Zn²⁺ + 2e^- → Zn: -0.76 V
• Fe²⁺ + 2e^- → Fe: -0.45 V
• Co²⁺ + 2e^- → Co: -0.28 V
• Cu²⁺ + 2e^- → Cu: +0.34 V

Step 5: Analyzing the Values

Now, let's analyze the SRPs of the 3d-series elements:

• Zinc (Zn): Has a negative electrode potential of -0.76 V, indicating a low tendency to be reduced.
• Iron (Fe): Has a negative electrode potential of -0.45 V, suggesting a weaker reduction tendency.
• Cobalt (Co): Has a negative electrode potential of -0.28 V, showing it is less likely to undergo reduction compared to others.
• Copper (Cu): Has a positive electrode potential of +0.34 V, indicating that copper is the only element in the 3d series that has a positive tendency to be reduced.

Step 6: Conclusion

From the analysis of the standard electrode potentials, we conclude that among the 3d-series elements, Copper (Cu) is the only element with a positive standard reduction potential. Therefore, Copper is the element in the 3d series that exhibits a positive SRP (M²⁺/M).

Final Answer

The 3d series element that has a positive SRP (M²⁺/M) is Copper (Cu).