Compare the stability of +2 oxidation state for the elements of the first transition series
Solution and Explanation
| Sc | +3 | |||||||
| Ti | +1 | +2 | +3 | +4 | ||||
| V | +1 | +2 | +3 | +4 | +5 | |||
| Cr | +1 | +2 | +3 | +4 | +5 | +6 | ||
| Mn | +1 | +2 | +3 | +4 | +5 | +6 | +7 | |
| Fe | +1 | +2 | +3 | +4 | +5 | +6 | ||
| Co | +1 | +2 | +3 | +4 | +5 | |||
| Ni | +1 | +2 | +3 | +4 | ||||
| Cu | +1 | +2 | +3 | |||||
| Zn | +2 |
From the above table, it is evident that the maximum number of oxidation states is shown by Mn, varying from +2 to +7. The number of oxidation states increases on moving from Sc to Mn. On moving from Mn to Zn, the number of oxidation states decreases due to a decrease in the number of available unpaired electrons. The relative stability of the +2 oxidation state increases on moving from top to bottom. This is because on moving from top to bottom, it becomes more and more difficult to remove the third electron from the d-orbital.
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Concepts Used:
D and F Block Elements
The d-block elements are placed in groups 3-12 and F-block elements with 4f and 5f orbital filled progressively. The general electronic configuration of d block elements and f- block elements are (n-1) d 1-10 ns 1-2 and (n-2) f 1-14 (n-1) d1 ns2 respectively. They are commonly known as transition elements because they exhibit multiple oxidation states because of the d-d transition which is possible by the availability of vacant d orbitals in these elements.
They have variable Oxidation States as well as are good catalysts because they provide a large surface area for the absorption of reaction. They show variable oxidation states to form intermediate with reactants easily. They are mostly lanthanoids and show lanthanoid contraction. Since differentiating electrons enter in an anti-penultimate f subshell. Therefore, these elements are also called inner transition elements.
Read More: The d and f block elements