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प्रश्न
Which of the following characteristics of transition metals is associated with their catalytic activity?
विकल्प
Paramagnetic nature
Colour of hydrated ions
High enthalpy of atomisation
Variable oxidation states
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उत्तर
Variable oxidation states
Explanation:
Transition metals have a tendency to have varying oxidation states, which allows them to create unstable intermediates and provide a novel reaction path with a lower Ea. As a result, transition metals have catalytic activity.
संबंधित प्रश्न
Out of Mn3+ and Cr3+, which is more paramagnetic and why ?
(Atomic nos. : Mn = 25, Cr = 24)
An antifriction alloy made up of antimony with tin and copper, which is extensively used in machine bearings is called _______.
(A) Duralumin
(B) Babbitt metal
(C) Spiegeleisen
(D) Amalgam
Explain why transition metals and their compounds act as a catalyst.
Explain why Mn2+ is more stable than Fe2+ towards oxidation to +3 state. (At. no. of Mn = 25, Fe = 26)
When acidified \[\ce{K2Cr2O7}\] solution is added to \[\ce{Sn^{2+}}\] salts then \[\ce{Sn^{2+}}\] changes to ______.
When a brown compound of manganese (A) is treated with \[\ce{HCl}\] it gives a gas (B). The gas taken in excess, reacts with \[\ce{NH3}\] to give an explosive compound (C). Identify compounds A, B and C.
Match the properties given in Column I with the metals given in Column II.
| Column I (Property) | Column II (Metal) | |
| (i) | An element which can show +8 oxidation state | (a) \[\ce{Mn}\] |
| (ii) | 3d block element that can show | (b) \[\ce{Cr}\] |
| upto +7 oxidation state | (c) \[\ce{Os}\] | |
| (iii) | 3d block element with highest melting point | (d) \[\ce{Fe}\] |
Among the following pairs of ions, the lower oxidation state in aqueous solution is more stable than the other in:-
Account for the following:
Transition metals form alloys.
Decide which of the following atomic numbers are the atomic numbers of the inner transition elements:
29, 59, 74, 95, 102, 104
