Advertisements
Advertisements
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+
Advertisements
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.
APPEARS IN
संबंधित प्रश्न
What are lanthanoids?
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.
Write the different oxidation states of iron
Explain, why lanthanum (Z = 57) forms La3+ ion, while cerium (Z = 58) forms Ce4+ ion?
Account for the following:
Zn, Cd and Hg are soft metals.
What is lanthanoid contraction? Write the.............
What is the action of the following on lanthanoids?
a. water
b. Sulphur, heat
c. nitrogen, heat
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:
Radii of 4d and 5d block elements.
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.
Which of the following pairs has the same ionic size?
In lanthanoid the last electron enters (n - 2)f subshell where n is equal to ______.
Zr (Z = 40) and Hf (Z = 72) have similar atomic and ionic radii because of ______.
The lathanide ion that would show colour is ______.
Write a note on lanthanoids.
Trivalent Lanthanoid ions such as La3+ (Z = 57) and Lu3+ (Z = 71) do not show any colour in their solution. Give a reason.
Name an important alloy which contains some of the lanthanoid metals.
