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प्रश्न
Mention any three processes where transition metals act as catalysts.
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उत्तर
(i) Vanadium (V) oxide in contact process for oxidation of \[\ce{SO2}\] to \[\ce{SO3}\].
(ii) Finely divided iron in Haber’s process in conversion of \[\ce{N2}\] and \[\ce{H2}\] to \[\ce{NH3}\].
(iii) \[\ce{MnO2}\] in preparation of oxygen from \[\ce{KClO3}\].
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संबंधित प्रश्न
In the series Sc (Z = 21) to Zn (Z = 30), the enthalpy of atomization of zinc is the lowest, i.e., 126 kJ mol−1. Why?
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.
Describe the oxidising action of potassium dichromate and write the ionic equation for its reaction with iodide.
Which metal in the first series of transition metals exhibits +1 oxidation state most frequently and why?
Calculate the number of unpaired electrons in the following gaseous ions:
Mn3+, Cr3+, V3+ and Ti3+. Which one of these is the most stable in an aqueous solution?
Use Hund’s rule to derive the electronic configuration of Ce3+ ion and calculate its magnetic moment on the basis of ‘spin-only’ formula.
Which one of the following ions is coloured?
Give reasons:
E° value for the Mn3+/Mn2+ couple is much more positive than that for Fe3+/Fe2+.
Account for the following :
Ti4+ is colourless whereas V4+ is coloured in an aqueous solutions.
When \[\ce{KMnO4}\] solution is added to oxalic acid solution, the decolourisation is slow in the beginning but becomes instantaneous after some time because ______.
Which of the following will not act as oxidising agents?
(i) \[\ce{CrO3}\]
(ii) \[\ce{MoO3}\]
(iii) \[\ce{WO3}\]
(iv) \[\ce{CrO^{2-}4}\]
Mention the type of compounds formed when small atoms like H, C and N get trapped inside the crystal lattice of transition metals. Also give physical and chemical characteristics of these compounds.
It has been observed that first ionization energy of 5 d series of transition elements are higher than that of 3d and 4d series, explain why?
Which does not belong to first transition series?
Which one of the following characters tie of the transition metal is associated with higher catalytic activity?
Which one among the following metals of the 3d series has the lowest melting point?
Compare the general characteristics of the first series of the transition metals with those of the second and third series metals in the respective vertical columns. Give special emphasis on the following point:
Ionisation enthalpies
