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प्रश्न
Why +2 oxidation state of manganese is more stable?
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उत्तर
- Manganese, having five unpaired electrons, exhibits six different oxidation states. The small energy difference between the 3d and 4s orbitals allows manganese to lose electrons from both, resulting in oxidation states ranging from +2 to +7.
- Electronic configuration of Mn2+ = [Ar]3d54s0
- Half-filled (d5) d-orbitals provide the Mn2+ ion additional stability, making Mn in the +2 oxidation state more stable.
संबंधित प्रश्न
Complete the following chemical equations:
`(i) Cr_2O_7^(2-)+6Fe^(2+)+14H^+ ->`
`(ii) 2CrO_4^(2-)+2H^+ ->`
`(iii) 2MnO_4^-+5C_2O_4^(2-)+16H^+ ->`
Account for the following:
Cr2+ is a strong reducing agent.
The elements of 3d transition series are given as: Sc Ti V Cr Mn Fe Co
Answer the following: Which element has the highest m.p?
Why do the transition elements have higher enthalpies of atomisation?
In 3d series (Sc to Zn), which element has the lowest enthalpy of atomisation and why?
Account for the following:
Cu+ ion is unstable in aqueous solution.
|
`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.
How is the variability in oxidation states of transition metals different from that of the non-transition metals? Illustrate with examples.
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.
Give reasons:
E° value for the Mn3+/Mn2+ couple is much more positive than that for Fe3+/Fe2+.
The transition metals show _________ character because of the presence of unpaired· electrons and Cu+ is ____________ because of its electronic configuration is [Ar]3d10
The paramagnetic character in the 3d-transition series elements increases up to Mn and then decreases.
Electronic configuration of a transition element X in +3 oxidation state is [Ar]3d5. What is its atomic number?
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 |
Interstitial compounds are formed when small atoms are trapped inside the crystal lattice of metals. Which of the following is not the characteristic property of interstitial compounds?
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) \[\ce{Cr^{3+}}\]
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) \[\ce{Ni}\] |
Assertion: Separation of \[\ce{Zr}\] and \[\ce{Hf}\] is difficult.
Reason: Because \[\ce{Zr}\] and \[\ce{Hf}\] lie in the same group of the periodic table.
Answer the following question:
Which element of the first transition series has lowest enthalpy of atomisation?
Mention any three processes where transition metals act as catalysts.
Why are fluorides of transition metals more stable in their higher oxidation state as compared to the lower oxidation state?
If enthalpies of formation of C2H4(g), CO2(g) and H2O(l) at 25°C and 1 atm pressure are 52, – 394 and – 286 kJ/mol respectively, the change in ethalpy for combustion of C2H4 is equal to
Which of the following maxm magnetic moment?
Passing H2S gas into a mixture of Mn2+ and Ni2+, Cu2+, ions in an acidified aqueous solution precipitates.
The basic character of transition metals monoxide follow the order.
Account for the following:
Copper has an exceptionally positive `"E"_("M"^(2+)//"M")^0` value.
