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प्रश्न
Compare the chemistry of actinoids with that of the lanthanoids with special reference to oxidation state.
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उत्तर
Lanthanoids show limited oxidation states (+2, +3, +4), in which the +3 oxidation state is the most common. This is because of the large energy gap between the 4f, 5d, and 6s subshells. On the other hand, actinoids show a large number of oxidation states because the energy gap between 5f, 6d, and 7s subshells is smaller.
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संबंधित प्रश्न
Define lanthanoid contraction.
What are chemical twins? Write ‘two’ examples.
The chemistry of the actinoid elements is not so smooth as that of the Lanthanoids. Justify this statement by giving some examples from the oxidation state of these elements.
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)
Name an element of lanthanoid series which is well knwon to shown +4 oxidation state. Is it a strong oxidising agent or reducing agent?
What is the action of the following on lanthanoids?
a. water
b. Sulphur, heat
c. nitrogen, heat
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:
Trends in the stability of oxo salts of lanthanoids from \[\ce{La}\] to \[\ce{Lu}\].
In lanthanoid the last electron enters (n - 2)f subshell where n is equal to ______.
Write any two consequences of Lanthanoid Contraction.
The lathanide ion that would show colour is ______.
Cerium (Z = S8) is an important member of lanthanoids. Which of the following statements about cerium is incorrect?
Why is Mn2+ ion more stable than Fe2+ ion?
(Atomic numbers of Mn = 25 and Fe = 26)
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.
Name an important alloy which contains some of the lanthanoid metals. Mention its uses.
The pair of lanthanoid ions which are diamagnetic is:
