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प्रश्न
On the basis of Lanthanoid contraction, explain the following:
Trends in acidic character of lanthanoid oxides.
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उत्तर
Acidic or basic character of oxides is related to the nature of oxides. As we move along the lanthanide series from \[\ce{La}\] to \[\ce{Lu}\], the covalent character increases.
Therefore, their basic character decreases or acidic character increases.
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संबंधित प्रश्न
Define lanthanoid contraction.
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.
Explain, why lanthanum (Z = 57) forms La3+ ion, while cerium (Z = 58) forms Ce4+ ion?
Explain the cause of Lanthanoids contraction.
What is lanthanoid contraction? Write the.............
What is lanthanoid contraction?
The f-block elements are known as ____________.
Gadolinium belongs to 4f series. It’s atomic number is 64. Which of the following is the correct electronic configuration of gadolinium?
General electronic configuration of actinoids is `(n-2)f^(1-14)(n - 1)d^(0-2)ns^2`.Which of the following actinoids have one electron in 6d orbital?
(i) U (Atomic no. 92)
(ii) Np (Atomic no.93)
(iii) Pu (Atomic no. 94)
(iv) Am (Atomic no. 95)
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) \[\ce{Ho}\]
Although +3 is the characteristic oxidation state for lanthanoids but cerium also shows +4 oxidation state because:
(i) it has variable ionisation enthalpy
(ii) it has a tendency to attain noble gas configuration
(iii) it has a tendency to attain f 0 configuration
(iv) it resembles Pb4+
Match the statements given in Column I with the oxidation states given in Column II.
| Column I | Column II | |
| (i) | Oxidation state of Mn in MnO2 is | (a) + 2 |
| (ii) | Most stable oxidation state of Mn is | (b) + 3 |
| (iii) | Most stable oxidation state of | (c) + 4 |
| Mn in oxides is | (d) + 5 | |
| (iv) | Characteristic oxidation state of lanthanoids is | (e) + 7 |
On the basis of Lanthanoid contraction, explain the following:
Nature of bonding in \[\ce{La2O3}\] and \[\ce{Lu2O3}\] .
How would you account for the following:
There is a greater range of oxidation states among the actinoids than among the lanthanides.
Mischmetal is an alloy consisting mainly of ______.
State a reason for the following:
La(OH)3 is more basic than Lu(OH)3.
Name an important alloy which contains some of the lanthanoid metals.
The pair of lanthanoid ions which are diamagnetic is:
