Advertisements
Advertisements
Question
Why are Mn2+ compounds more stable than Fe2+ towards oxidation to their +3 state?
Solution
The electronic configuration of Mn2+ is [Ar]18 3d5 while that of Fe2+ is [Ar] 3d6. Since Mn2+ has a half-filled orbit (3d5), which is more stable than the 3d6 orbit of Fe2+, Mn2+ compounds are not easily oxidised to Mn3+ because of very high second ionization enthalpy. In contrast, Fe2+ compounds are easily oxidised to Fe3+ due to lower second ionization enthalpy. This is the reason that Mn2+ compounds are more stable than Fe2+ towards oxidation to their +3 state.
APPEARS IN
RELATED QUESTIONS
How would you account for the following?
Transition metals exhibit variable oxidation states.
Calculate magnetic moment of `Fe_((aq))^(2+) ion (Z=26).`
Account for the following:
Cu+2 salts are coloured, while Zn2+ salts are white.
Account for the following :
Zn is not considered as a transition element.
Out of Mn3+ and Cr3+, which is more paramagnetic and why ?
(Atomic nos. : Mn = 25, Cr = 24)
Why is the highest oxidation state of a metal exhibited in its oxide or fluoride only?
Calculate the ‘spin only’ magnetic moment of \[\ce{M^{2+}_{ (aq)}}\] ion (Z = 27).
In what way is the electronic configuration of the transition elements different from that of the non-transition elements?
Maximum oxidation state is shown by ____________.
In lake test for Al3+ ions, there is the formation of coloured ‘floating lake’. It is due to ______.
Generally transition elements form coloured salts due to the presence of unpaired electrons. Which of the following compounds will be coloured in solid-state?
The magnetic nature of elements depends on the presence of unpaired electrons. Identify the configuration of transition element, which shows highest magnetic moment.
Although Zirconium belongs to 4d transition series and Hafnium to 5d transition series even then they show similar physical and chemical properties because ______.
The halides of transition elements become more covalent with increasing oxidation state of the metal. Why?
Match the solutions given in Column I and the colours given in Column II.
| Column I (Aqueous solution of salt) |
Column II (Colour) |
| (i) \[\ce{FeSO2.7H2O}\] | (a) Green |
| (ii) \[\ce{NiCl2.4H2O}\] | (b) Light pink |
| (iii) \[\ce{MnCl2.4H2O}\] | (c) Blue |
| (iv) \[\ce{CoC12,6H2O}\] | (d) Pale green |
| (v) \[\ce{Cu2 Cl2}\] | (e) Pink |
| (f) Colourless |
Match the properties given in Column I with the metals given in Column II.
| Column I (Property) | Column II (Metal) | |
| (i) | Element with highest second ionisation enthalpy |
(a) \[\ce{Co}\] |
| (ii) | Element with highest third ionisation enthalpy |
(b) \[\ce{Cr}\] |
| (iii) | \[\ce{M}\] in \[\ce{M(CO)6}\] is | (c) \[\ce{Cu}\] |
| (iv) | Element with highest heat of atomisation |
(d) \[\ce{Zn}\] |
| (e) \[\ce{Ni}\] |
Agcl is soluble in NH4OH. The solubility is due to the information of:-
The electrode potential of M2+/M of 3d-series elements shows the positive value for ______.
Write the number of unpaired electrons in Cr3+.
(Atomic number of Cr = 24)
