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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
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?
Account for the following:
Cu+ ion is unstable in aqueous solution.
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.
How is the variability in oxidation states of transition metals different from that of the non-transition metals? Illustrate with examples.
What is meant by ‘disproportionation’?
The transition metals show _________ character because of the presence of unpaired· electrons and Cu+ is ____________ because of its electronic configuration is [Ar]3d10
Explain why transition metals and their compounds act as a catalyst.
Electronic configuration of Mn2+ is ____________.
Read the passage given below and answer the following question:
The transition metals when exposed to oxygen at low and intermediate temperatures form thin, protective oxide films of up to some thousands of Angstroms in thickness. Transition metal oxides lie between the extremes of ionic and covalent binary compounds formed by elements from the left or right side of the periodic table. They range from metallic to semiconducting and deviate by both large and small degrees from stoichiometry. Since electron bonding levels are involved, the cations exist in various valence states and hence give rise to a large number of oxides. The crystal structures are often classified by considering a cubic or hexagonal close-packed lattice of one set of ions with the other set of ions filling the octahedral or tetrahedral interstices. The actual oxide structures, however, generally show departures from such regular arrays due in part to distortions caused by packing of ions of different size and to ligand field effects. These distortions depend not only on the number of d-electrons but also on the valence and the position of the transition metal in a period or group.
In the following questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices on the basis of the above passage.
Assertion: Crystal structure of oxides of transition metals often show defects.
Reason: Ligand field effect cause distortions in crystal structures.
Highest oxidation state of manganese in fluoride is \[\ce{+4 (MnF4)}\] but highest oxidation state in oxides is \[\ce{+7 (Mn2O7)}\] because ______.
Identify the metal and justify your answer.
Carbonyl \[\ce{M(CO)5}\]
Which one of the following characters tie of the transition metal is associated with higher catalytic activity?
Give reasons for the following statement:
Zn, Cd, and Hg are soft metals.
Why Zn, Cd and Hg are not called transition metals?
Which of the following ions acts as a typical transition metal ion?
The oxidation state of Fe in [Fe(CO)5] is ______.
Which of the following characteristics of transition metals is associated with their catalytic activity?
Which of the following transition metals shows +1 and +2 oxidation states?
Give two similarities in the properties of Sc and Zn.
Give a reason for the following:
Transition metals possess a great tendency to form complex compounds.
