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प्रश्न
Mention uses of alloys.
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उत्तर
Misch metal is used in Mg-based alloys to produce bullets, shells, and lighter flint. It is used as a reducing agent in metallurgical operations. Magnesium alloys containing about 30% misch metal and 1% Zr are used for making parts of a jet engine
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संबंधित प्रश्न
Which among the following pairs of elements is 'not' an example of chemical twins?
Compare the chemistry of actinoids with that of lanthanoids with special reference to electronic configuration.
Write the different oxidation states of iron
Explain, why lanthanum (Z = 57) forms La3+ ion, while cerium (Z = 58) forms Ce4+ ion?
Explain effects of lanthanoid contraction.
What are the consequences of lanthanoid contraction?
Account for the following:
Zn, Cd and Hg are soft metals.
Explain the cause of Lanthanoids contraction.
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 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 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.
In lanthanoid the last electron enters (n - 2)f subshell where n is equal to ______.
Cerium (Z = S8) is an important member of lanthanoids. Which of the following statements about cerium is incorrect?
State a reason for the following:
La(OH)3 is more basic than Lu(OH)3.
The pair of lanthanoid ions which are diamagnetic is:
