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प्रश्न
Which of the d-block elements may not be regarded as the transition elements?
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उत्तर
The electronic configuration of Zn, Cd and Hg is represented by the general formula (n – 1)d10ns2. In these elements, the orbitals are completely filled in the ground (normal) state as well as in ordinary oxidation states, i.e., the subshells are not incomplete in their atomic state or any one of the ionic states. Therefore, they cannot be called transition elements.
संबंधित प्रश्न
Which metal in the first transition series (3d series) exhibits + 1 oxidation state most frequently and why?
Account for the following:
Cr2+ is a strong reducing agent.
Account for the following:
Cu+ ion is unstable in aqueous solution.
How would you account for the following:
Of the d4 species, Cr2+ is strongly reducing while manganese (III) is strongly oxidising.
Why do transition metal ions possess a great tendency to form complexes?
Maximum oxidation state is shown by ____________.
Interstitial compounds are formed when small atoms are trapped inside the crystal lattice of metals. Which of the following is not the characteristic property of interstitial compounds?
Highest oxidation state of manganese in fluoride is \[\ce{+4 (MnF4)}\] but highest oxidation state in oxides is \[\ce{+7 (Mn2O7)}\] because ______.
The second and third rows of transition elements resemble each other much more than they resemble the first row. Explain why?
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.
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.
The standard electrode potentials of four elements A, B, C and D are – 3.05, – 1.66, – 0.40 and + 0.80. The highest chemical reactivity will be exhibited by
Photographic film and plates have - au essential ingredient of
Sodium this sulphate is used in photography because of its:-
The electrode potential of M2+/M of 3d-series elements shows the positive value for ______.
Consider the following standard electrode potential values:
\[\ce{Sn^{2+}_{ (aq)} + 2e^- -> Sn_{(s)}}\]; E0 = −0.14 V
\[\ce{Fe^{3+}_{ (aq)} + e^- -> Fe^{2+}_{ (aq)}}\]; E0 = +0.77 V
What is the cell reaction and potential for the spontaneous reaction that occurs?
Write the ionic equation for reaction of KI with acidified KMnO4.
Account for the following:
Zirconium (Zr) and Hafnium (Hf) are difficult to separate.
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:
Atomic sizes
Match List-I with List-II.
| List-I | List-II |
| A. Haber process | I. Fe catalyst |
| B. Wacker oxidation | II. PdCl2 |
| C. Wilkinson catalyst | III. [(PPh3)3RhCl] |
| D. Ziegler catalyst | IV. TiCl4 with Al(CH3)3 |
Choose the correct answer from the options given below:
