Q. 705.0( 2 Votes )
(a) Transition metals can act as catalysts because these can change their oxidation state. How does Fe(III) catalyse the reaction between iodide and persulphate ions?
(b) Mention any three processes where transition metals act as catalysts.
(a) Fe(III) acting as catalyst for the reaction between iodide and persulphate ions.
2Fe3+ + 2I-→ 2Fe2+ + I2
2Fe2+ + S2O82-→ 2Fe3+ + 2SO42-
(b) Three processes where transition metals act as catalysts.
(i) Finely divided Nickel as catalyst for hydrogenation of vegetable oil
(ii) V2O5 as catalyst for contact process used in the manufacture of sulphuric acid
(iii) Finely divided iron as catalyst for Haber’s process in the manufacture of ammonia
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Match the catalysts given in Column I with the processes given in Column II.
Indicate the steps in the preparation of:
(i) K2Cr2O7 from chromite ore. (ii) KMnO4 from pyrolusite ore.NCERT - Chemistry Part-I
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Match the compounds/elements given in Column I with uses given in Column II.
Describe the preparation of potassium permanganate. How does the acidified permanganate solution react with (i) iron(II) ions (ii) SO2 and (iii) oxalic acid?
Write the ionic equations for the reactions.NCERT - Chemistry Part-I
What are interstitial compounds? Why are such compounds well known for transition metals?NCERT - Chemistry Part-I
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For M2+/M and M3+/M2+ systems the EV values for some metals are as follows:
Use this data to comment upon:
(i) the stability of Fe3+ in acid solution as compared to that of Cr3+ or Mn3+ and
(ii) the ease with which iron can be oxidized as compared to a similar process for either chromium or manganese metal.NCERT - Chemistry Part-I