Advertisements
Advertisements
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.
Advertisements
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.
\[\ce{2MnO2 + 4KOH + O2 -> 2K2MnO4 + 2H2O}\]
\[\ce{3MnO^{2-}_4 + 4H^+ -> 2MnO^-_4 + MnO2 + 2H2O}\]
The chemical reactions of acidic potassium permanganate are as follows:
\[\ce{MnO^-_4 + 8H^+ + 5Fe^2+ -> Mn^2+ + 4H2O + 5Fe^3+}\]
संबंधित प्रश्न
Complete the following equation:
\[\ce{2MnO4- + 6H+ + 5NO2- ->}\]
Complete the following equations : MnO4- + 4H+ + 3e- →
Complete the following equation : MnO4- + 8H+ + 5e- →
Give an example and suggest a reason for the following feature of the transition metal chemistry:
The lowest oxide of transition metal is basic, the highest is amphoteric/acidic.
Give an example and suggest a reason for the following feature of the transition metal chemistry:
A transition metal exhibits the highest oxidation state in oxides and fluorides.
Answer the following question.
When MnO2 is fused with KOH in the presence of KNO3 as an oxidizing agent, it gives a dark green compound (A). Compound (A) disproportionates in an acidic solution to give a purple compound (B). An alkaline solution of compound (B) oxidizes KI to compound (C) whereas an acidified solution of compound (B) oxidizes KI to (D). Identify (A), (B), (C), and (D).
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.
When \[\ce{Cu^2+}\] ion is treated with \[\ce{KI}\], a white precipitate is formed. Explain the reaction with the help of chemical equation.
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.
What is the effect of pH on dichromate ion solution?
Complete the following ionic equation:
\[\ce{Cr2O^{2-}7 + 2OH^- ->}\]
In the two tetrahedral structures of dichromate ion, ______.
Complete the reaction mentioning all the products formed:
\[\ce{Cr2O^{2-}7 + 3H2S + 8H^+ ->}\]
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.
Describe the preparation of potassium permanganate. How does the acidified permanganate solution react with oxalic acid? Write the ionic equation for the reaction.
