Advertisements
Advertisements
Question
Describe the preparation of potassium permanganate. How does the acidified permanganate solution react with oxalic acid? Write the ionic equation for the reaction.
Advertisements
Solution
Potassium permanganate can be made by the following methods:
In the laboratory, salts of the manganese (II) ion are oxidized by oxydisulfate to form permanganates.
\[\ce{MnO^-_4 + 8H+ + 5e- -> Mn^{2+} + 4H2O] \times 2}\]
\[\begin{array}{cc}
\ce{COO-}\phantom{.....................}\\
5| \ce{-> 10CO2 + 10e-}\\
\ce{COO-}\phantom{.....................}\\
\end{array}\]
______________________________________________________
\[\ce{2MnO^-_4 + 16H+ + 5C2O^{2-}_4 -> 2Mn^{2+} + 10CO2 + 8H2O}\]
RELATED QUESTIONS
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 equation :
`2MnO_4^(-)+6H^++5NO_2^(-)rarr`
Complete the following chemical equation
Cr2O72- + 3Sn2+ + 14H+ →
Describe the preparation of potassium dichromate from iron chromite ore. What is the effect of increasing pH on a solution of potassium dichromate?
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.
Indicate the steps in the preparation of K2Cr2O7 from chromite ore.
Indicate the steps in the preparation of KMnO4 from pyrolusite ore.
Write the formula of an oxo-anion of Manganese (Mn) in which it shows the oxidation state equal to its group number.
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+ ?
Which of the following is amphoteric oxide?
\[\ce{Mn2O7, CrO3, Cr2O3, CrO, V2O5, V2O4}\]
\[\ce{KMnO4}\] acts as an oxidising agent in alkaline medium. When alkaline \[\ce{KMnO4}\] is treated with \[\ce{KI}\], iodide ion is oxidised to ______.
When \[\ce{Cu^2+}\] ion is treated with \[\ce{KI}\], a white precipitate is formed. Explain the reaction with the help of chemical equation.
The product formed upon heating methyl bromide with potassium tert-butoxide is
Potassium permanganate on heating at 513 K gives a product which is ______.
Complete the following ionic equation:
\[\ce{Cr2O^{2-}7 + 2OH^- ->}\]
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.
