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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
What are interstitial compounds?
How would you account for the following : Transition metals form coloured compounds
What are inner transition elements?
Write the formula of an oxo-anion of Chromium (Cr) in which it shows the oxidation state equal to its group number
Complete and balance the following chemical equations
`Fe^(2+) + MnO_4^(-) + H^+ ->`
Account for the following :
Ti4+ is colourless whereas V4+ is coloured in an aqueous solutions.
Explain why transition elements form alloys.
Explain why Mn2+ is more stable than Fe2+ towards oxidation to +3 state. (At. no. of Mn = 25, Fe = 26)
The magnetic nature of elements depends on the presence of unpaired electrons. Identify the configuration of transition element, which shows highest magnetic moment.
\[\ce{KMnO4}\] acts as an oxidising agent in acidic medium. The number of moles of \[\ce{KMnO4}\] that will be needed to react with one mole of sulphide ions in acidic solution is ______.
When acidified \[\ce{K2Cr2O7}\] solution is added to \[\ce{Sn^{2+}}\] salts then \[\ce{Sn^{2+}}\] changes to ______.
A violet compound of manganese (A) decomposes on heating to liberate oxygen and compounds (B) and (C) of manganese are formed. Compound (C) reacts with KOH in the presence of potassium nitrate to give compound (B). On heating compound (C) with conc. \[\ce{H2SO4}\] and \[\ce{NaCl}\], chlorine gas is liberated and a compound (D) of manganese along with other products is formed. Identify compounds A to D and also explain the reactions involved.
Which of the following ions will exhibit colour in aqueous solution?
Which of the following characteristics of transition metals is associated with their catalytic activity?
Account for the following:
Ce4+ is a strong oxidising agent.
Assertion (A): Transition metals show their highest oxidation state with oxygen.
Reason (R): The ability of oxygen to form multiple bonds to metals.
Complete the following reaction and justify that it is a disproportionation reaction:
\[\ce{3MnO^{2-}4 + 4H^+ -> \underline{}\underline{}\underline{}\underline{} + \underline{}\underline{}\underline{}\underline{} + 2H2O}\]
In order to protect iron from corrosion, which one will you prefer as a sacrificial electrode, Ni or Zn? Why? (Given standard electrode potentials of Ni, Fe and Zn are -0.25 V, -0.44 V and -0.76 V respectively.)
Why are interstitial compounds well known for transition metals?
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.
