Advertisements
Advertisements
प्रश्न
Transition metals can act as catalysts because these can change their oxidation state. How does \[\ce{Fe(III)}\] catalyse the reaction between iodide and persulphate ions?
Advertisements
उत्तर
Reaction between iodide and persulphate ions is:
\[\ce{2I^{-} + S2O^{2-}8 ->[Fe(III)] I2 + 2SO^{2-}4}\]
Role of \[\ce{Fe(III)}\] ions:
\[\ce{2Fe^{3+} + 2I^{-} -> 2Fe^{2+} + I2}\]
\[\ce{2Fe^{2+} + S2O^{2-}8 -> 2Fe^{3+} + 2SO^{2-}4}\]
APPEARS IN
संबंधित प्रश्न
Why is Sc3+ colourless while Ti3+ coloured? (Atomic number Sc = 21, Ti =22)
Which of the 3d series of the transition metals exhibits the largest number of oxidation states and why?
How would you account for the following:
Of the d4 species, Cr2+ is strongly reducing while manganese (III) is strongly oxidising.
NF3 is possible, but NF5 is not. Why?
Write balanced chemical equations for the conversion of `CrO_4^(2-)` to `Cr_2O_7^(2-)` in acidic medium and `Cr_2O_7^(2-)` to `CrO_4^(2-)`
in basic medium.
Account for the following :
Ti4+ is colourless whereas V4+ is coloured in an aqueous solutions.
Explain why transition metals and their compounds act as a catalyst.
Transition metals with highest melting point is ____________.
In lake test for Al3+ ions, there is the formation of coloured ‘floating lake’. It is due to ______.
Why is \[\ce{HCl}\] not used to make the medium acidic in oxidation reactions of \[\ce{KMnO4}\] in acidic medium?
Which of the following will not act as oxidising agents?
(i) \[\ce{CrO3}\]
(ii) \[\ce{MoO3}\]
(iii) \[\ce{WO3}\]
(iv) \[\ce{CrO^{2-}4}\]
Match the solutions given in Column I and the colours given in Column II.
| Column I (Aqueous solution of salt) |
Column II (Colour) |
| (i) \[\ce{FeSO2.7H2O}\] | (a) Green |
| (ii) \[\ce{NiCl2.4H2O}\] | (b) Light pink |
| (iii) \[\ce{MnCl2.4H2O}\] | (c) Blue |
| (iv) \[\ce{CoC12,6H2O}\] | (d) Pale green |
| (v) \[\ce{Cu2 Cl2}\] | (e) Pink |
| (f) Colourless |
Identify A to E and also explain the reactions involved.
Consider the following standard electrode potentials (E° in volts) in aqueous solution:
| Element | M3+/M | M+/M |
| Al | - 1.66 | +0.55 |
| Tl | + 1.26 | -0.34 |
Based on these data, which of the following statements is correct?
Account for the following:
Sc3+ is colourless whereas Ti3+ is coloured in an aqueous solution.
Which property of transition metals enables them to behave as catalysts?
Consider the following standard electrode potential values:
\[\ce{Fe^{3+}_{ (aq)} + e^- -> Fe^{2+}_{ (aq)}}\], E0 = +0.77 V
\[\ce{MnO^{-4}_{ (aq)} + 8H^+ + 5e^- -> Mn^{2+}_{ (aq)} + 4H2O_{(l)}}\], E0 = +1.51 V
What is the cell potential for the redox reaction?
What is the oxidation state of chromium in chromate ion and dichromate ion?
Why are interstitial compounds well known for transition metals?
