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प्रश्न
Which is a stronger reducing agent, Cr2+ or Fe2+ and why?
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उत्तर
Cr2+ is a stronger reducing agent than Fe2+. In the formation of Cr2+ to Cr3+, the change is d4 to d3, but in the formation of Fe2+ to Fe3+, the change is d6 to d5. In a medium like water, d3 is more stable than d5.
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संबंधित प्रश्न
|
`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.
Account for the following:
Zn is not considered as a transition element.
Explain why Cu+ ion is not stable in aqueous solutions?
In what way is the electronic configuration of the transition elements different from that of the non-transition elements?
Which metal in the first series of transition metals exhibits +1 oxidation state most frequently and why?
Which one of the following ions is coloured?
How would you account for the following?
Transition metals and their compounds act as catalysts.
Why do transition metal ions possess a great tendency to form complexes?
Transition elements show magnetic moment due to spin and orbital motion of electrons. Which of the following metallic ions have almost same spin only magnetic moment?
(i) \[\ce{Co^{2+}}\]
(ii) \[\ce{Cr^{2+}}\]
(iii) \[\ce{Mn^{2+}}\]
(iv) \[\ce{Cr^{3+}}\]
Although \[\ce{Cr^3+}\] and \[\ce{Co^2+}\] ions have same number of unpaired electrons but the magnetic moment of \[\ce{Cr^3+}\] is 3.87 B.M. and that of \[\ce{Co^2+}\] is 4.87 B.M. Why?
The second and third rows of transition elements resemble each other much more than they resemble the first row. Explain why?
Reactivity of transition elements decreases almost regularly from Sc to Cu. Explain.
Why are fluorides of transition metals more stable in their higher oxidation state as compared to the lower oxidation state?
A metallic ion 'M' reacts with chloride ion to form white precipitate which is readily soluble in aqueous ammonia. Identify 'M'?
The product of oxidation of I– with \[\ce{MnO^{-}4}\] in alkaline medium is:-
Account for the following:
Sc3+ is colourless whereas Ti3+ is coloured in an aqueous solution.
Which property of transition metals enables them to behave as catalysts?
The second ionization enthalpies of chromium and manganese are 1592 and 1509 kJ/mol respectively. Explain the lower value of Mn.
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
