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प्रश्न
Write any two consequences of Lanthanoid Contraction.
उत्तर
- Due to the close similarity in electronic configuration and ionic radii, the lanthanides have identical chemical properties, which make their separation difficult.
- Due to lanthanide contraction, the size of Ln3+ ions decreases regularly with an increase in atomic number. According to Fajan's rule, a decrease in the size of Ln3+ ions increases the covalent character and decreases the basic character between Ln3+ and OH– ion in Ln(OH)3. Since the order of size of Ln3+ ions is La3+ > Ce3+ ... > Lu3+.
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संबंधित प्रश्न
Define lanthanoid contraction.
Account for the following :
Zr and Hf have almost similar atomic radii.
Compare the chemistry of actinoids with that of the lanthanoids with special reference to oxidation state.
Name the members of the lanthanoid series which exhibit +4 oxidation state and those which exhibit +2 oxidation state. Try to correlate this type of behavior with the electronic configurations of these elements.
What is lanthanoid contraction? Write the.............
Which of the following lanthanoids show +2 oxidation state besides the characteristic oxidation state +3 of lanthanoids?
(i) \[\ce{Ce}\]
(ii) \[\ce{Eu}\]
(iii) \[\ce{Yb}\]
(iv) \[\ce{Ho}\]
Match the property given in Column I with the element given in Column II.
| Column I (Property) | Column II (Element) | |
| (i) | Lanthanoid which shows +4 oxidation state |
(a) Pm |
| (ii) | Lanthanoid which can show +2 oxidation state |
(b) Ce |
| (iii) | Radioactive lanthanoid | (c) Lu |
| (iv) | Lanthanoid which has 4f7 electronic configuration in +3 oxidation state |
(d) Eu |
| (v) | Lanthanoid which has 4f14 electronic configuration in +3 oxidation state |
(e) Gd |
| (f) Dy |
On the basis of Lanthanoid contraction, explain the following:
Stability of the complexes of lanthanoids.
Zr (Z = 40) and Hf (Z = 72) have similar atomic and ionic radii because of _______.
Assertion: There is a continuous increase in size among Lanthanoids with an increase in atomic number.
Reason: Lanthanoids do not show Lanthanoid contraction.
