Advertisements
Advertisements
प्रश्न
What is the action of the following on lanthanoids?
a. water
b. Sulphur, heat
c. nitrogen, heat
Advertisements
उत्तर
- Action of water on lanthanoids: Reaction of water with lanthanoids gives ionic and basic lanthanide hydroxides (Ln(OH)3) with liberation of H2 gas.
Ln + 3H2O → Ln(OH)3 + 3H2 - Action of sulphur on lanthanoids: Heating of sulphur with
lanthanoids gives lanthanide sulphide (Ln2S3).
\[\ce{2Ln + 3S ->[\Delta] Ln2S3}\] - Action of nitrogen on lanthanoids: Reaction of nitrogen with lanthanoide gives lanthanide nitride (LnN).
\[\ce{2Ln + N2 ->[\Delta] 2LnN}\]
APPEARS IN
संबंधित प्रश्न
What are lanthanoids?
Account for the following :
Zr and Hf have almost similar atomic radii.
Name a member of the lanthanoid series which is well known to exhibit +4 oxidation state.
What are the different oxidation states exhibited by the lanthanoids?
Compare the chemistry of actinoids with that of lanthanoids with special reference to electronic configuration.
Write the electronic configuration of the element with the atomic number 61.
Write the different oxidation states of iron
Explain effects of lanthanoid contraction.
Account for the following:
Zn, Cd and Hg are soft metals.
Explain the cause of Lanthanoids contraction.
The f-block elements are known as ____________.
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:
Radii of 4d and 5d block elements.
The titanium (Z = 22) compound that does not exist is:-
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 ______.
Write any two consequences of Lanthanoid Contraction.
The lathanide ion that would show colour is ______.
Mischmetal is an alloy consisting mainly of ______.
State a reason for the following:
La(OH)3 is more basic than Lu(OH)3.
Why is Mn2+ ion more stable than Fe2+ ion?
(Atomic numbers of Mn = 25 and Fe = 26)
Assertion: There is a continuous increase in size among Lanthanoids with an increase in atomic number.
Reason: Lanthanoids do not show Lanthanoid contraction.
Name an important alloy which contains some of the lanthanoid metals. Mention its uses.
