Advertisements
Advertisements
Question
Write the chemical equation for the preparation of 4 KMnO from 2. MnO Why does purple colour of acidified permanganate solution decolourise when it oxidises Fe2- to Fe3+ ?
Advertisements
Solution
Chemical equations for the preparation of KMnO4 from MnO2
2MnO2 + 4KOH + O2 → 2K2MnO4 + 2H2O
`3MnO_4^2+4H -> 2MnO_4^- + 2 MnO_4^- + MnO_2 + 2H_2O `
\[\ce{ MnO_2 ->[Fused with oxidised][with air or KNO3]}MnO_4^{2-}\] maganate ion
\[\ce{ \underset{Manganate}{MnO_4^{2-}} ->[Electrolytic oxidation][in alkaline solution] MnO_4^- }\] permanganateion
Purple colour of acidified permanganate solution decolourise when it oxidises Fe2- + Fe3+
In acidic medium, Reduction
KMnO4 is behaving as oxidising Agent.
So, purple colour of acidified 4 KMnO solutions decolourises.
APPEARS IN
RELATED QUESTIONS
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.
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.
Which of the following reactions are disproportionation reactions?
(a) \[\ce{Cu^{+} -> Cu^{2+} + Cu}\]
(b) \[\ce{3MnO^{-}4 + 4H^{+} -> 2MnO^{-}4 + MnO2 + 2H2O}\]
(c) \[\ce{2KMnO4 -> K2MnO4 + MnO2 + O2}\]
(d) \[\ce{2MnO^{-}4 + 3Mn^{2+} + 2H2O -> 5MnO2 + 4H^{+}}\]
In the two tetrahedral structures of dichromate ion, ______.
Indicate the steps in the preparation of \[\ce{K2Cr2O7}\] from chomite 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.
