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Question
Mention any three processes where transition metals act as catalysts.
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Solution
(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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RELATED QUESTIONS
Complete the following chemical equations:
`(i) Cr_2O_7^(2-)+6Fe^(2+)+14H^+ ->`
`(ii) 2CrO_4^(2-)+2H^+ ->`
`(iii) 2MnO_4^-+5C_2O_4^(2-)+16H^+ ->`
Account for the following:
Cr2+ is a strong reducing agent.
In 3d series (Sc to Zn), which element has the lowest enthalpy of atomisation and why?
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?
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How is potassium dichromate prepared from chrome iron ore?
Transition metals with lowest melting point is ______.
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Why EΘ values for Mn, Ni and Zn are more negative than expected?
Match the catalysts given in Column I with the processes given in Column II.
| Column I (Catalyst) | Column II (Process) |
| (i) \[\ce{Ni}\] in the presence of hydrogen | (a) Zieglar Natta catalyst |
| (ii) \[\ce{Cu2C12}\] | (b) Contact process |
| (iii) \[\ce{V2O5}\] | (c) Vegetable oil to ghee |
| (iv) Finely divided iron | (d) Sandmeyer reaction |
| (v) \[\ce{TiCl4 + Al (CH3)3}\] | (e) Haber's Process |
| (f) Decomposition of KCIO3 |
Among the following pairs of ions, the lower oxidation state in aqueous solution is more stable than the other in:-
Which one of the following characters tie of the transition metal is associated with higher catalytic activity?
In the ground state of atomic Fe (Z = 26), the spin-only magnetic moment is ______ × 10-1 BM.
(Round off to the nearest integer).
[Given: `sqrt3 = 1.73, sqrt2 = 1.41`]
Assertion (A): Transition metals show their highest oxidation state with oxygen.
Reason (R): The ability of oxygen to form multiple bonds to metals.
Which of the following ions has the electronic configuration 3d6?
(Atomic number: Mn = 25, Co = 27, Ni = 28)
Explain the magnetic properties of d-block (or transition) elements.
Give a reason for the following:
Zinc, cadmium and mercury are considered as d-block elements but not regarded as transition elements.
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.
