Advertisements
Advertisements
प्रश्न
Describe the preparation of potassium permanganate. How does the acidified permanganate solution react with SO2? Write the ionic equation for the reaction.
Indicate the steps in the preparation of KMnO4 from pyrolusite ore.
उत्तर १
Potassium permanganate can be made by the following methods –
It is produced industrially by the electrolytic oxidation of manganate (VI), followed by the alkaline oxidative fusion of MnO2.
\[\ce{MnO2 ->[Fused with KOH, oxidised with air or KNO3] \underset{manganate ion}{MnO^{2-}_4}}\]
\[\ce{\underset{manganate}{MnO^{2-}_4} ->[Electrolytic oxidation in alkaline solution] \underset{permanganate ion}{MnO^-_4}}\]
The chemical reactions of acidic potassium permanganate are as follows –
\[\ce{2MnO^-4 + 2H2O + 5SO2 -> 2Mn^{2+} + 4H^+ + 5SO^{2-}_4}\]
उत्तर २
\[\ce{2MnO2 + 4KOH + O2 ->[\Delta] 2K2MnO4 + 2H2O}\]
\[\ce{3MnO^2-_4 + 4H+ -> 2MnO^-_4 + MnO2 + 2H2O}\]
संबंधित प्रश्न
When chromite ore FeCr2O4 is fused with NaOH in presence of air, a yellow-coloured compound (A) is obtained, which on acidification with dilute sulphuric acid gives a compound (B). Compound (B) on reaction with KCl forms an orange coloured crystalline compound (C).
(i) Write the formulae of the compounds (A), (B) and C.
(ii) Write one use of compound (C).
Complete the following equations : MnO4- + 4H+ + 3e- →
Describe the preparation of potassium dichromate from iron chromite ore. What is the effect of increasing pH on a solution of potassium dichromate?
Describe the preparation of potassium permanganate. How does the acidified permanganate solution react with iron (II) ions? Write the ionic equation for the reaction.
Indicate the steps in the preparation of KMnO4 from pyrolusite ore.
Name a member of the lanthanoid series that is well-known to exhibit +2 oxidation state.
Account for the following :
Manganese shows maximum number of oxidation states in 3d series.
Potassium permanganate on heating at 513 K gives a product which is ______.
Indicate the steps in the preparation of \[\ce{K2Cr2O7}\] from chromite ore.
Describe the preparation of potassium permanganate. How does the acidified permanganate solution react with oxalic acid? Write the ionic equation for the reaction.
