Advertisements
Advertisements
Question
How would you account for the following:
Cobalt (II) is stable in aqueous solutions, but in the presence of complexing reagents, it is easily oxidised.
Advertisements
Solution
In the presence of complexing reagents, the crystal field stabilization energy is greater than the third ionization enthalpy of cobalt. Thus, Co (II) is easily oxidized to Co (III).
RELATED QUESTIONS
Why do interstitial compounds have higher melting points than corresponding pure metals?
Explain why is Fe3+ more stable than Fe2+?
Calculate magnetic moment of `Fe_((aq))^(2+) ion (Z=26).`
Account for the following:
Cr2+ is a strong reducing agent.
Account for the following:
Cu+2 salts are coloured, while Zn2+ salts are white.
The elements of 3d transition series are given as: Sc Ti V Cr Mn Fe Co
Answer the following: Which element is a strong oxidising agent in +3 oxidation state and why?
How would you account for the following: Transition metals form complex compounds.
Account for the following:
Zn is not considered as a transition element.
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?
Why do transition metals exhibit higher enthalpy of atomization?
Maximum magnetic moment is shown by ____________.
Identify A to E and also explain the reactions involved.

Mention any three processes where transition metals act as catalysts.
Fill in the blanks by choosing the appropriate word(s) from those given in the brackets:
(activation energy, Threshold energy, increased, lowered, partially, full, d-d transition, Benzoic acid, benzaldehyde)
Only those transition metal ions will be coloured which have ______ filled d-orbitals facilitating ______.
Photographic film and plates have - au essential ingredient of
Which property of transition metals enables them to behave as catalysts?
The given graph shows the trends in melting points of transition metals:

Explain the reason why Cr has the highest melting point and manganese (Mn) has a lower melting point.
A transition element X has an electronic configuration [Ar]4s23d3. Predict its likely oxidation states.
Account for the following:
Eu2+ with electronic configuration [Xe]4f76s2 is a strong reducing agent.
