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प्रश्न
Explain why Cu+ ion is not stable in aqueous solutions?
Out of Cu+ and Cu2+, which ion is unstable in aqueous solution and why?
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उत्तर
\[\ce{Cu^{2+}_{ (aq)}}\] is more stable than \[\ce{Cu^{+}_{ (aq)}}\]. This is because copper has a higher second ionization enthalpy, but ΔhydH for \[\ce{Cu^{2+}_{ (aq)}}\] is more negative than that for \[\ce{Cu^{+}_{ (aq)}}\], so it compensates more for the second ionization enthalpy of copper. Thus many copper (I) compounds are unstable in aqueous solution and are disproportionated as follows:
\[\ce{2Cu^{+}_{ (aq)} -> Cu^{2+}_{ (aq)} + Cu_{(s)}}\]
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संबंधित प्रश्न
Account for the following:
Zn is not considered as a transition element.
Account for the following:
E° value for the Mn3+/Mn2+ couple is much more positive than that for Cr3+/Cr2+.
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To what extent do the electronic configurations decide the stability of oxidation states in the first series of the transition elements? Illustrate your answer with examples.
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).
Give reasons:
E° value for the Mn3+/Mn2+ couple is much more positive than that for Fe3+/Fe2+.
Why do transition elements show variable oxidation states ? In 3d series (Sc to Zn), which elements shows the maximum number of oxidation state and why ?
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Explain why transition elements form alloys.
Transition metals with lowest melting point is ______.
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 |
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Mention any three processes where transition metals act as catalysts.
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