Properties Of D Block Elements

Step 1: Understanding the Concept:
The standard electrode potential ( ) for transition metals indicates their tendency to be reduced from the state to the solid metal. A more negative value implies the solid metal is a stronger reducing agent and more easily oxidized to the state. The trend across the 3d series is generally towards less negative values, but important exceptions exist due to stable electronic configurations (like for ).

Step 2: Key Formula or Approach:
This requires recalling the standard reduction potential values (or their general trends) for the 3d series elements.

Step 3: Detailed Explanation:
Let's list the approximate standard reduction potentials ( for ) for the given metals:
- Vanadium (V):
- Chromium (Cr):
- Manganese (Mn):
- Iron (Fe):
- Cobalt (Co):
Notice that Manganese breaks the general trend of becoming less negative. The value for Mn is more negative than expected (and similar to V) because the resulting ion has a highly stable, half-filled electron configuration. This makes solid Mn relatively eager to oxidize to , driving the reduction potential down.
Arranging these values in increasing order (from most negative to least negative):

Therefore, the order is V Mn Cr Fe Co.

Step 4: Final Answer:
The increasing order of standard electrode potentials is V Mn Cr Fe Co.