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प्रश्न
How would you account for the following:
The d1 configuration is very unstable in ions.
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उत्तर
In ions, the d1 configuration is unstable, but after losing one electron, it becomes more stable due to the vacant d-orbitals. All elements with d1 configuration are oxidised or undergo disproportionation. e.g.,
\[\ce{3\overset{+6}{\underset{3d^1}{Mn}}O^2-_4 + 4H+ -> 2\overset{+7}{\underset{3d^0}{Mn}}O^-_4 + \overset{+4}{Mn}O2 + 2H2O}\]
संबंधित प्रश्न
Which metal in the first transition series (3d series) exhibits + 1 oxidation state most frequently and why?
Account for the following:
Cu+ ion is unstable in aqueous solution.
|
`E_((M^(2+)/M)` |
Cr | Mn | Fe | Co | Ni | Cu |
| -0.91 | -1.18 | -0.44 | -0.28 | -0.25 | -0.34 |
From the given data of E0 values, answer the following questions :
(1) Why is `E_(((Cu^(2+))/(Cu)))` value exceptionally positive
(2) Why is `E_(((Mn^(2+))/(Mn)))` value is highly negative as compared to other elements
(3) Which is the stronger reducing agents Cr2+ or Fe2+ ? Give Reason.
Which of the 3d series of the transition metals exhibits the largest number of oxidation states and why?
The \[\ce{E^{\circ}_{(M^{2+}/M)}}\] value for copper is positive (+0.34 V). What is possible reason for this? (Hint: consider its high ΔaH° and low ΔhydH°)
How would you account for the following:
Cobalt (II) is stable in aqueous solutions, but in the presence of complexing reagents, it is easily oxidised.
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:
Electronic configurations
How would you account for the following?
Zr (Z = 40) and Hf (Z = 72) have almost identical radii.
Complete and balance the following chemical equations
`Fe^(2+) + MnO_4^(-) + H^+ ->`
Give reasons: Sc3+ is colourless in aqueous solution whereas Ti3+ is coloured.
The transition metals show _________ character because of the presence of unpaired· electrons and Cu+ is ____________ because of its electronic configuration is [Ar]3d10
Give reasons for the following:
The transition metals generally form coloured compounds.
Transition metals with highest melting point is ____________.
Electronic configuration of a transition element X in +3 oxidation state is [Ar]3d5. What is its atomic number?
While filling up of electrons in the atomic orbitals, the 4s orbital is filled before the 3d orbital but reverse happens during the ionisation of the atom. Explain why?
When an oxide of manganese (A) is fused with KOH in the presence of an oxidising agent and dissolved in water, it gives a dark green solution of compound (B). Compound (B) disproportionates in neutral or acidic solution to give purple compound (C). An alkaline solution of compound (C) oxidises potassium iodide solution to a compound (D) and compound (A) is also formed. Identify compounds A to D and also explain the reactions involved.
Catalytic hydrogenation of benzene gives
Sodium this sulphate is used in photography because of its:-
Assertion (A): Transition metals show their highest oxidation state with oxygen.
Reason (R): The ability of oxygen to form multiple bonds to metals.
