Advertisements
Advertisements
प्रश्न
To what extent do the electronic configurations decide the stability of oxidation states in the first series of the transition elements? Illustrate your answer with examples.
Advertisements
उत्तर
- The ions in the oxidation state, in which the ions have fully filled or half-filled d shells, are more stable.
- For example, the +2 state of Mn is more stable than its other oxidation states.
- Because Mn2+ has a half-filled 3d5 shell. Similarly, the +2 state of Zn is its most stable state because it has a fully filled 3d10 shell.
APPEARS IN
संबंधित प्रश्न
Why +2 oxidation state of manganese is more stable?
How would you account for the following:
Of the d4 species, Cr2+ is strongly reducing while manganese (III) is strongly oxidising.
An antifriction alloy made up of antimony with tin and copper, which is extensively used in machine bearings is called _______.
(A) Duralumin
(B) Babbitt metal
(C) Spiegeleisen
(D) Amalgam
NF3 is possible, but NF5 is not. Why?
An analysis shows that FeO has a non-stoichiometric composition with formula Fe0.95O. Give reason.
Give reasons Iron has the higher enthalpy of atomization than that of copper.
Which among the following transition metal has the lowest melting point?
Why EΘ values for Mn, Ni and Zn are more negative than expected?
Explain why does colour of KMnO4 disappear when oxalic acid is added to its solution in acidic medium.
The second and third rows of transition elements resemble each other much more than they resemble the first row. Explain why?
Match the solutions given in Column I and the colours given in Column II.
| Column I (Aqueous solution of salt) |
Column II (Colour) |
| (i) \[\ce{FeSO2.7H2O}\] | (a) Green |
| (ii) \[\ce{NiCl2.4H2O}\] | (b) Light pink |
| (iii) \[\ce{MnCl2.4H2O}\] | (c) Blue |
| (iv) \[\ce{CoC12,6H2O}\] | (d) Pale green |
| (v) \[\ce{Cu2 Cl2}\] | (e) Pink |
| (f) Colourless |
Mention the type of compounds formed when small atoms like H, C and N get trapped inside the crystal lattice of transition metals. Also give physical and chemical characteristics of these compounds.
A violet compound of manganese (A) decomposes on heating to liberate oxygen and compounds (B) and (C) of manganese are formed. Compound (C) reacts with KOH in the presence of potassium nitrate to give compound (B). On heating compound (C) with conc. \[\ce{H2SO4}\] and \[\ce{NaCl}\], chlorine gas is liberated and a compound (D) of manganese along with other products is formed. Identify compounds A to D and also explain the reactions involved.
Account for the following:
Transition metals form alloys.
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`]
The disproportionation of \[\ce{MnO^{2-}_4}\] in acidic medium resulted in the formation of two manganese compounds A and B. If the oxidation state of Mn in B is smaller than that of A, then the spin-only magnetic moment (µ) value of B in BM is ______. (Nearest integer)
The second ionization enthalpies of chromium and manganese are 1592 and 1509 kJ/mol respectively. Explain the lower value of Mn.
Write the ionic equation for reaction of KI with acidified KMnO4.
Decide which of the following atomic numbers are the atomic numbers of the inner transition elements:
29, 59, 74, 95, 102, 104
