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प्रश्न
Describe the preparation of potassium permanganate. How does the acidified permanganate solution react with iron (II) ions? Write the ionic equation for the reaction.
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उत्तर
Potassium permanganate is prepared by fusion of MnO2 with an alkali metal hydroxide and an oxidising agent like KNO3. This produces the dark green K2MnO4, which disproportionates in a neutral or acidic solution to give permanganate.
\[\ce{2MnO2 + 4KOH + O2 -> 2K2MnO4 + 2H2O}\]
Potassium manganate is extracted with water and thereafter disproportionates in neutral or acidic solution to yield potassium permanganate.
\[\ce{3MnO^{2-}_4 + 4H^+ -> 2MnO^-_4 + MnO2 + 2H2O}\]
In an acidic medium of dilute sulphuric acid, KMnO4 acts as a strong oxidising agent, and it reacts as:
\[\ce{MnO^-_4 + 8H^+ + 5e- -> Mn^2+ + 4H2O}\]
Ferrous (Fe2+) ion solution to ferric (Fe3+) ion solution
\[\ce{MnO^-_4 + 8H+ + 5e- -> Mn^{2+} + 4H2O}\]
\[\ce{5Fe^{2+} -> 5Fe^{3+} + 5e-}\]
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\[\ce{MnO^-_4 + 5Fe^{2+} + 8H+ -> Mn^{2+} + 5Fe^{3+} + 4H2O}\]
संबंधित प्रश्न
Complete the following equation:
\[\ce{2MnO4- + 6H+ + 5NO2- ->}\]
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 chemical equation
8MnO4- + 3S2O32- + H2O →
Complete the following equations:Cr2O72- + 2OH- →
Name the oxometal anions of the first series of the transition metals in which the metal exhibits the oxidation state equal to its group number.
Indicate the steps in the preparation of K2Cr2O7 from chromite ore.
Account for the following :
Manganese shows maximum number of oxidation states in 3d series.
Using IUPAC norms, write the formula of potassium trioxalatochromate(III).
On addition of small amount of \[\ce{KMnO4}\] to concentrated \[\ce{H2SO4}\], a green oily compound is obtained which is highly explosive in nature. Identify the compound from the following.
\[\ce{KMnO4}\] acts as an oxidising agent in alkaline medium. When alkaline \[\ce{KMnO4}\] is treated with \[\ce{KI}\], iodide ion is oxidised to ______.
The product formed upon heating methyl bromide with potassium tert-butoxide is
In the two tetrahedral structures of dichromate ion, ______.
Which of the following ions will have a magnetic moment value of 1.73 BM.
\[\ce{Sc^3+, Ti^3+, Ti^2+, Cu^2+, Zn^2+}\]
Indicate the steps in the preparation of \[\ce{K2Cr2O2}\] from chromite ore.
Indicate the step in the preparation of K2Cr2O7 from chromite ore.
Indicate the steps in the preparation of 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.
Describe the preparation of potassium permanganate. How does the acidified permanganate solution react with SO2? Write the ionic equation for the reaction.
