Advertisements
Advertisements
Question
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?
Advertisements
Solution
| 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.
RELATED QUESTIONS
What are inner transition elements?
Write down the number of 3d electrons in the following ion:
Cu2+
Indicate how would you expect the five 3d orbitals to be occupied for this hydrated ion (octahedral).
What can be inferred from the magnetic moment value of the following complex species?
| Example | Magnetic Moment (BM) |
| K2[MnCl4] | 5.9 |
An analysis shows that FeO has a non-stoichiometric composition with formula Fe0.95O. Give reason.
Explain why transition metals and their compounds act as a catalyst.
Transition metals with lowest melting point is ______.
Maximum magnetic moment is shown by ____________.
Out of \[\ce{Cu2Cl2}\] and \[\ce{CuCl2}\], which is more stable and why?
Ionisation enthalpies of Ce, Pr and Nd are higher than Th, Pa and U. Why?
Account for the following:
In case of transition elements, ions of the same charge in a given series show progressive decrease in radius with increasing atomic number.
On the basis of the figure given below, answer the following questions:
- Why Manganese has lower melting point than Chromium?
- Why do transition metals of 3d series have lower melting points as compared to 4d series?
- In the third transition series, identify and name the metal with the highest melting point.
The product of oxidation of I– with \[\ce{MnO^{-}4}\] in alkaline medium is:-
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?
Give reasons for the following statement:
Zn, Cd, and Hg are soft metals.
The number of terminal oxygen atoms present in the product B obtained from the following reactions is:
\[\ce{FeCr2O4 + Na2CO3 + O2 -> A + Fe2O3 + CO2}\]
\[\ce{A + H^+ -> B + H2O + Na^+}\]
Assertion (A): Transition metals have high enthalpy of atomisation.
Reason (R): Greater number of unpaired electrons in transition metals results in weak metallic bonding.
Which of the following ions has the electronic configuration 3d6?
(Atomic number: Mn = 25, Co = 27, Ni = 28)
For M2+/M and M3+/M2+systems, the EΘ 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 ease with which iron can be oxidised as compared to a similar process for either chromium or manganese metal.
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
