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प्रश्न
Following are the transition metal ions of 3d series:
Ti4+, V2+, Mn3+, Cr3+
(Atomic numbers: Ti = 22, V = 23, Mn = 25, Cr = 24)
Answer the following:
1) Which ion is most stable in an aqueous solution and why?
2) Which ion is a strong oxidising agent and why?
3) Which ion is colourless and why?
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उत्तर
1)
| Gaseous ions | Number of unpaired electrons |
| Ti4+, [Ar] 3d0 | 0 |
| V2+, [Ar] 3d3 | 3 |
| Mn3+, [Ar] 3d4 | 4 |
| Cr3+, [Ar] 3d3 | 3 |
V2+ and Cr3+ are the most stable ions in aqueous solutions owing to `t_(2g)^3` a configuration.
2) An examination of the Eo values for the redox couple M3+/M2+ (from electrode potential table) shows that Mn3+ ion are the strongest oxidising agents in aqueous solutions.
3) Only the ions that have electrons in d-orbital and in which d-d transition is possible will be coloured. The ions in which d-orbitals are empty or completely filled will be colourless as no d-d transition is possible in those configurations.
From the given transition metal ions, it can be easily observed that only Ti4+ has an empty d-orbital, so, it is colourless ion.
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संबंधित प्रश्न
Why is Sc3+ colourless while Ti3+ coloured? (Atomic number Sc = 21, Ti =22)
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?
|
`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 following statements is not correct?
Why does copper not replace hydrogen from acids?
Assertion (A): Cu cannot liberate hydrogen from acids.
Reason (R): Because it has positive electrode potential.
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 element with atomic number 53 belongs to
The complex showing a spin-span magnetic moment of 2.82 B.M. is :-
Account for the following:
Eu2+ with electronic configuration [Xe]4f76s2 is a strong reducing agent.
