Advertisements
Advertisements
Question
Why do interstitial compounds have higher melting points than corresponding pure metals?
Advertisements
Solution
The melting points of interstitial compounds are higher than those of pure metals because of bonding between the metal and the non-metal, which is stronger than metal–metal bonding.
APPEARS IN
RELATED QUESTIONS
Complete the following chemical equations:
`(i) Cr_2O_7^(2-)+6Fe^(2+)+14H^+ ->`
`(ii) 2CrO_4^(2-)+2H^+ ->`
`(iii) 2MnO_4^-+5C_2O_4^(2-)+16H^+ ->`
The elements of 3d transition series are given as: Sc Ti V Cr Mn Fe Co
Answer the following: Which element shows only +3 oxidation state?
How would you account for the following: Transition metals form complex compounds.
In the series Sc (Z = 21) to Zn (Z = 30), the enthalpy of atomization of zinc is the lowest, i.e., 126 kJ mol−1. Why?
Which of the d-block elements may not be regarded as the transition elements?
How is the variability in oxidation states of transition metals different from that of the non-transition metals? Illustrate with examples.
Which metal in the first series of transition metals exhibits +1 oxidation state most frequently and why?
What are alloys?
What are inner transition elements?
Complete and balance the following chemical equations
`MnO_4^(-) + H_2O + I^(-) ->`
Explain why transition elements form alloys.
Explain why transition metals and their compounds act as a catalyst.
\[\ce{KMnO4}\] acts as an oxidising agent in acidic medium. The number of moles of \[\ce{KMnO4}\] that will be needed to react with one mole of sulphide ions in acidic solution is ______.
When acidified \[\ce{K2Cr2O7}\] solution is added to \[\ce{Sn^{2+}}\] salts then \[\ce{Sn^{2+}}\] changes to ______.
Although Zirconium belongs to 4d transition series and Hafnium to 5d transition series even then they show similar physical and chemical properties because ______.
Match the catalysts given in Column I with the processes given in Column II.
| Column I (Catalyst) | Column II (Process) |
| (i) \[\ce{Ni}\] in the presence of hydrogen | (a) Zieglar Natta catalyst |
| (ii) \[\ce{Cu2C12}\] | (b) Contact process |
| (iii) \[\ce{V2O5}\] | (c) Vegetable oil to ghee |
| (iv) Finely divided iron | (d) Sandmeyer reaction |
| (v) \[\ce{TiCl4 + Al (CH3)3}\] | (e) Haber's Process |
| (f) Decomposition of KCIO3 |
Assertion: Separation of \[\ce{Zr}\] and \[\ce{Hf}\] is difficult.
Reason: Because \[\ce{Zr}\] and \[\ce{Hf}\] lie in the same group of the periodic table.
Answer the following question:
Which element of the first transition series has lowest enthalpy of atomisation?
Identify the metal and justify your answer.
Carbonyl \[\ce{M(CO)5}\]
On the basis of the figure given below, answer the following questions:

- Why Manganese has lower melting point than Chromium?
- Why do transition metals of 3d series have lower melting points as compared to 4d series?
- In the third transition series, identify and name the metal with the highest melting point.
The element with atomic number 46 belongs to
The product of oxidation of I– with \[\ce{MnO^{-}4}\] in alkaline medium is:-
Give reasons for the following statement:
Zn, Cd, and Hg are soft metals.
In the ground state of atomic Fe (Z = 26), the spin-only magnetic moment is ______ × 10-1 BM.
(Round off to the nearest integer).
[Given: `sqrt3 = 1.73, sqrt2 = 1.41`]
Which of the following transition metals shows +1 and +2 oxidation states?
Account for the following:
Zirconium (Zr) and Hafnium (Hf) are difficult to separate.
Why are interstitial compounds well known for transition metals?
Compare the general characteristics of the first series of the transition metals with those of the second and third series metals in the respective vertical columns. Give special emphasis on the following point:
Ionisation enthalpies
