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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Give one chemical test to distinguish between the following pairs of compounds.
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(ii) Secondary and tertiary amines
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(iv) Aniline and benzylamine
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(ii) Ethylamine is soluble in water whereas aniline is not.
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Write down the electronic configuration of:
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- Explain briefly how +2 state becomes more and more stable in the first half of the first row transition elements with increasing atomic number?
- To what extent do the electronic configurations decide the stability of oxidation states in the first series of the transition elements? Illustrate your answer with examples.
What may be the stable oxidation state of the transition element with the following d electron configurations in the ground state of their atoms : 3d3 ,3d5 ,3d8 and 3d4?
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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