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प्रश्न
Calculate the number of unpaired electrons in the following gaseous ions:
Mn3+, Cr3+, V3+ and Ti3+. Which one of these is the most stable in an aqueous solution?
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उत्तर
| Gaseous ions | Electronic configurations | Number of unpaired electrons |
| Mn3+ | 3d4 4s0 | 4 |
| Cr3+ | 3d3 4s0 | 3 |
| V3+ | 3d2 4s0 | 2 |
| Ti3+ | 3d1 4s0 | 1 |
Of these, Cr3+ is most stable in aqueous solution because it has a half-filled \[\ce{t^3_2g}\] level.
संबंधित प्रश्न
What are the transition elements? Write two characteristics of the transition elements.
Why is the highest oxidation state of a metal exhibited in its oxide or fluoride only?
For M2+/M and M3+/M2+ systems, the E° values for some metals are as follows:
| Cr2+/Cr | −0.9 V |
| Mn2+/Mn | −1.2 V |
| Fe2+/Fe | −0.4 V |
| Cr3/Cr2+ | −0.4 V |
| Mn3+/Mn2+ | +1.5 V |
| Fe3+/Fe2+ | +0.8 V |
Use this data to comment upon:
- The stability of Fe3+ in acid solution as compared to that of Cr3+ or Mn3+ and
- the ease with which iron can be oxidised as compared to a similar process for either chromium or manganese metal.
Compare the stability of +2 oxidation state for the elements of the first transition series.
Which one of the following ions is coloured?
How would you account for the following?
Zr (Z = 40) and Hf (Z = 72) have almost identical radii.
Why do transition metals exhibit higher enthalpy of atomization?
Maximum magnetic moment is shown by ____________.
Why EΘ values for Mn, Ni and Zn are more negative than expected?
The second and third rows of transition elements resemble each other much more than they resemble the first row. Explain why?
Assertion (A): Cu cannot liberate hydrogen from acids.
Reason (R): Because it has positive electrode potential.
Fill in the blanks by choosing the appropriate word(s) from those given in the brackets:
(activation energy, Threshold energy, increased, lowered, partially, full, d-d transition, Benzoic acid, benzaldehyde)
Only those transition metal ions will be coloured which have ______ filled d-orbitals facilitating ______.
The element with atomic number 46 belongs to
On adding NaOH, solution to the aqueous solution of K2CrO7 the colour of the solution changes from
Which of the following ions has the maximum magnetic moment?
Which of the following transition metal is not coloured?
The number of terminal oxygen atoms present in the product B obtained from the following reactions is:
\[\ce{FeCr2O4 + Na2CO3 + O2 -> A + Fe2O3 + CO2}\]
\[\ce{A + H^+ -> B + H2O + Na^+}\]
Which of the following transition metals shows +1 and +2 oxidation states?
Give two similarities in the properties of Sc and Zn.
The compounds of \[\ce{Ti^4+}\] ions are colourless due to ______.
