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प्रश्न
Give reasons: E° value for the Mn3+/Mn2+ couple is much more positive than that for Fe3+/Fe2+.
उत्तर
`E_(Mn^(3+)"/"Mn^(2+))^@` = more positive
`E_(Fe^(3+)"/"Fe^(2+))^@` = less positive
`Mn^(2+) = d^5s^@`
`Mn^(3+) = d^4`
]
Because Mn2+ is more stable than Mn3+. Hence, Mn3+ will have tendency to go in +2 state.
Whereas in case of Fe, Fe3+ is more stable than Fe2+ hence, it have less positive value.
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संबंधित प्रश्न
The elements of 3d transition series are given as: Sc Ti V Cr Mn Fe Co
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Explain why Cu+ ion is not stable in aqueous solutions?
What are the characteristics of the transition elements and why are they called transition elements?
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The transition metals generally form coloured compounds.
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 ______.
Write the number of unpaired electrons in Cr3+.
(Atomic number of Cr = 24)
Account for the following:
Zirconium (Zr) and Hafnium (Hf) are difficult to separate.
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.
