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प्रश्न
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+ ?
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उत्तर
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.
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संबंधित प्रश्न
Complete the following equations:

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 : 2 MnO2 + 4 KOH + O2 →
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`2MnO_4^(-)+16H^++5S^(2-)rarr`
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.
Why \[\ce{HCl}\] should not be used for potassium permanganate titrations?
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.
