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Question
Describe the preparation of potassium permanganate. How does the acidified permanganate solution react with SO2? Write the ionic equation for the reaction.
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Solution
Potassium permanganate can be made by the following methods:
It is produced industrially by the alkaline oxidative fusion of MnO2 followed by the electrolytic oxidation of manganate (VI).
\[\ce{MnO2 ->[Fused with KOH, oxidised with air or KNO3] \underset{manganate ion}{MnO^2-_4}}\]
\[\ce{\underset{manganate}{MnO^2-_4} ->[Electrolytic oxidation in alkaline solution] \underset{permanganate ion}{MnO^-_4}}\]
The chemical reactions of acidic potassium permanganate are as follows:
\[\ce{2MnO^-4 + 2H2O + 5SO2 -> 2Mn^2+ + 4H^+ + 5SO^2-_4}\]
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RELATED QUESTIONS
Complete the following equations: Cr2O72- + 14H+ + 6I →
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Account for the following :
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E0 value for Mn3+ Mn2+ couple is much more positive than that for Cr3-/ Cr2-.
Generally transition elements and their salts are coloured due to the presence of unpaired electrons in metal ions. Which of the following compounds are coloured?
(i) \[\ce{KMnO4}\]
(ii) \[\ce{Ce(SO4)2}\]
(iii) \[\ce{TiCl}\]
(iv) \[\ce{Cu2 Cl2}\]
In the form of dichromate, \[\ce{Cr (VI)}\] is a strong oxidising agent in acidic medium but \[\ce{Mo (VI)}\] in \[\ce{MoO3}\] \[\ce{and W (VI)}\] in \[\ce{WO3}\] are not because:
(i) \[\ce{Cr(VI)}\] is more stable than \[\ce{Mo(VI)}\] and \[\ce{and W(VI)}\].
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(iv) Lower oxidation states of heavier members of group-6 of transition series are more stable.
Potassium permanganate acts as an oxidant in neutral, alkaline as well as acidic media. The final products obtained from it in the three conditions are, respectively.
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Potassium permanganate on heating at 513 K gives a product which is ______.
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In the two tetrahedral structures of dichromate ion, ______.
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\[\ce{Cr2O^{2-}7 + 3H2S + 8H^+ ->}\]
Indicate the steps in the preparation of \[\ce{K2Cr2O7}\] from chromite ore.
Indicate the steps in the preparation of \[\ce{K2Cr2O7}\] from chromite ore.
Indicate the steps in the preparation of \[\ce{K2Cr2O7}\] from chromite ore.
Indicate the steps in the preparation of \[\ce{K2Cr2O7}\] from chromite ore.
