Advertisements
Advertisements
प्रश्न
Calculate magnetic moment of `Fe_((aq))^(2+) ion (Z=26).`
Advertisements
उत्तर
Data: Fe2+
Z=26
Electronic configuration of
`Fe^(2+)=1s^2 2s^2 2p^6 3s^2 3p^6 4s^@3d^6`
No. of unpaired electrons = 4
To find: Magnetic moment = u
Formula: `u=sqrt(n(n+2))B.M.`
Solution: `u=sqrt(4(4+2))`
`=sqrt24`
u = 4.90 B.M.
APPEARS IN
संबंधित प्रश्न
Why is Sc3+ colourless while Ti3+ coloured? (Atomic number Sc = 21, Ti =22)
What are interstitial compounds?
Account for the following:
Cu+2 salts are coloured, while Zn2+ salts are white.
Why do the transition elements have higher enthalpies of atomisation?
Give reasons:
Transition metals show variable oxidation states.
What are the characteristics of the transition elements and why are they called transition elements?
Compare the stability of +2 oxidation state for the elements of the first transition series.
How would you account for the following:
Of the d4 species, Cr2+ is strongly reducing while manganese (III) is strongly oxidising.
Which metal in the first series of transition metals exhibits +1 oxidation state most frequently and why?
Comment on the statement that elements of the first transition series possess many properties different from those of heavier transition elements.
What can be inferred from the magnetic moment value of the following complex species?
| Example | Magnetic Moment (BM) |
| K2[MnCl4] | 5.9 |
Give reasons Iron has the higher enthalpy of atomization than that of copper.
Why does the density of transition elements increase from Titanium to Copper? (at. no. Ti = 22, Cu = 29)
Read the passage given below and answer the following question:
The transition metals when exposed to oxygen at low and intermediate temperatures form thin, protective oxide films of up to some thousands of Angstroms in thickness. Transition metal oxides lie between the extremes of ionic and covalent binary compounds formed by elements from the left or right side of the periodic table. They range from metallic to semiconducting and deviate by both large and small degrees from stoichiometry. Since electron bonding levels are involved, the cations exist in various valence states and hence give rise to a large number of oxides. The crystal structures are often classified by considering a cubic or hexagonal close-packed lattice of one set of ions with the other set of ions filling the octahedral or tetrahedral interstices. The actual oxide structures, however, generally show departures from such regular arrays due in part to distortions caused by packing of ions of different size and to ligand field effects. These distortions depend not only on the number of d-electrons but also on the valence and the position of the transition metal in a period or group.
In the following questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices on the basis of the above passage.
Assertion: Transition metals form protective oxide films.
Reason: Oxides of transition metals are always stoichiometric.
Metallic radii of some transition elements are given below. Which of these elements will have highest density?
| Element | \[\ce{Fe}\] | \[\ce{Co}\] | \[\ce{Ni}\] | \[\ce{Cu}\] |
| Metallic radii/pm | 126 | 125 | 125 | 128 |
Highest oxidation state of manganese in fluoride is \[\ce{+4 (MnF4)}\] but highest oxidation state in oxides is \[\ce{+7 (Mn2O7)}\] because ______.
The second and third rows of transition elements resemble each other much more than they resemble the first row. Explain why?
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?
Identify the metal and justify your answer.
Carbonyl \[\ce{M(CO)5}\]
Which of the following is non-metallic?
The spin magnetic moment of cobalt in the compound Hg [Co(SCN)4] is:-
Among the following pairs of ions, the lower oxidation state in aqueous solution is more stable than the other in:-
Why Zn, Cd and Hg are not called transition metals?
Consider the following standard electrode potentials (E° in volts) in aqueous solution:
| Element | M3+/M | M+/M |
| Al | - 1.66 | +0.55 |
| Tl | + 1.26 | -0.34 |
Based on these data, which of the following statements is correct?
In the ground state of atomic Fe (Z = 26), the spin-only magnetic moment is ______ × 10-1 BM.
(Round off to the nearest integer).
[Given: `sqrt3 = 1.73, sqrt2 = 1.41`]
Which of the following characteristics of transition metals is associated with their catalytic activity?
Assertion (A): Transition metals show their highest oxidation state with oxygen.
Reason (R): The ability of oxygen to form multiple bonds to metals.
Which of the following ions has the electronic configuration 3d6?
(Atomic number: Mn = 25, Co = 27, Ni = 28)
Give a reason for the following.
Some transition metals and their compounds get attracted towards the magnetic field.
Describe the oxidising action of potassium dichromate and write the ionic equation for its reaction with iron (II) solution.
