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प्रश्न
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+
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उत्तर
(ii) it has a tendency to attain noble gas configuration
(iii) it has a tendency to attain f 0 configuration
Explanation:
Electronic configuration of cerium:
\[\ce{Ce - 4f^1 5d^1 6s^2}\]
\[\ce{Ce^4+ − 4f^0 5d^0 6s^0}\]
Lead has the tendency to lose its four outer electrons to attain Noble gas configuration and this removal of electrons corresponds to the f∘ configuration and cause it to be stable in +4 oxidation state.
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संबंधित प्रश्न
What are chemical twins? Write ‘two’ examples.
What are the different oxidation states exhibited by the lanthanoids?
Compare the chemistry of actinoids with that of the lanthanoids with special reference to oxidation state.
Compare the chemistry of actinoids with that of the lanthanoids with special reference to atomic and ionic sizes.
Compare the chemistry of actinoids with that of the lanthanoids with special reference to chemical reactivity.
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 effects of lanthanoid contraction.
Which trivalent ion has the maximum size in the Lanthanoid series, i.e., Lanthanum ion (La3+) to Luteium ion (Lu3+)?
(at. no. of Lanthanum = 57 and Lutetium = 71)
What is lanthanoid contraction? Write the.............
What is the action of the following on lanthanoids?
a. water
b. Sulphur, heat
c. nitrogen, heat
Gadolinium belongs to 4f series. It’s atomic number is 64. Which of the following is the correct electronic configuration of gadolinium?
On the basis of Lanthanoid contraction, explain the following:
Nature of bonding in \[\ce{La2O3}\] and \[\ce{Lu2O3}\] .
On the basis of Lanthanoid contraction, explain the following:
Trends in the stability of oxo salts of lanthanoids from \[\ce{La}\] to \[\ce{Lu}\].
On the basis of Lanthanoid contraction, explain the following:
Trends in acidic character of lanthanoid oxides.
How would you account for the following:
There is a greater range of oxidation states among the actinoids than among the lanthanides.
Write any two consequences of Lanthanoid Contraction.
Write a note on lanthanoids.
Why is Mn2+ ion more stable than Fe2+ ion?
(Atomic numbers of Mn = 25 and Fe = 26)
