New chat PYQ Library Doubts Rank report

Sign in to see Recents

Your guest activity stays on this device

Sign in to save progress →

Electrochemistry question

2024 · 30 Jan · Shift 2 · Q13

Guest · filters and generic practice availableBrowsing as a guest · PYQ filters and generic practice are available. Sign in only for personalised features and saved progress.

PYQ Library
JEE Main
Chemistry
Electrochemistry
2024 · 30 Jan · Shift 2 · Q13

Electrochemistry question

2024 · 30 Jan · Shift 2 · Q13

JEE MainChemistryElectrochemistryMCQ+4 / −1

Alkaline oxidative fusion of

\mathrm{MnO}_2

gives "A" which on electrolytic oxidation in alkaline solution produces B. A and B respectively are

A
$\mathrm{Mn}_2 \mathrm{O}_3$ and $\mathrm{MnO}_4^{2-}$
B
$\mathrm{Mn}_2 \mathrm{O}_7$ and $\mathrm{MnO}_4^{-}$
C
$\mathrm{MnO}_4^{2-}$ and $\mathrm{MnO}_4^{-}$
D
$\mathrm{MnO}_4^{2-}$ and $\mathrm{Mn}_2 \mathrm{O}_7$

View written solutionFree

Correct answer: C

Identify product of alkaline oxidative fusion of $\mathrm{MnO_2}$

When $\mathrm{MnO_2}$ is fused with alkali in presence of an oxidizing agent, it forms manganate.

A typical reaction is:

2\mathrm{MnO_2} + 4\mathrm{KOH} + \mathrm{O_2} \rightarrow 2\mathrm{K_2MnO_4} + 2\mathrm{H_2O}

Thus, the species "A" is:

\mathrm{MnO_4^{2-}}

Electrolytic oxidation of manganate in alkaline solution

Manganate ion on electrolytic oxidation in alkaline medium is oxidized to permanganate:

\mathrm{MnO_4^{2-}} \rightarrow \mathrm{MnO_4^-}

So, species "B" is:

\mathrm{MnO_4^-}

Match with options

We found:

$A = \mathrm{MnO_4^{2-}}$
$B = \mathrm{MnO_4^-}$

This matches Option C.

Final answer

A = \mathrm{MnO_4^{2-}}, \quad B = \mathrm{MnO_4^-}

Hence, the correct option is C.

More from Electrochemistry

Reduction potential of ions are given below: $ClO_{4}^{-} E^{\circ} = 1.19 V IO_{4}^{-} E^{\circ} = 1.65 V BrO_{4}^{-} E^{\circ} = 1.74 V$ …2024 · MCQ
Identify the factor from the following that does not affect electrolytic conductance of a solution.2024 · MCQ
Number of alkanes obtained on electrolysis of a mixture of $CH_{3} COONa$ and $C_{2} H_{5} COONa$ is .2024 · Numerical
One Faraday of electricity liberates $x \times 1 0^{- 1}$ gram atom of copper from copper sulphate. $x$ is .2024 · Numerical
The values of conductivity of some materials at $298.15 K^{- 1} in Sm^{- 1}$ are $2.1 \times 1 0^{3}$ , $1.0 \times 1 0^{- 16}, 1.2 \times 10, 3.91, 1.5 \times 1 0^{- 2}, 1 \times 1 0^{- 7}, 1.0 \times 1 0^{3}$ . The number of…2024 · Numerical
At what pH, given half cell $Mn O_{4}^{-} (0.1 M) ∣ M n^{2 +} (0.001 M)$ will have electrode potential of 1.282 V? (Nearest Integer) Given $E_{Mn O_{4}^{-} ∣M n^{2 +}}^{o} = 1.54 V, \frac{2.303 RT}{F} = 0.059 V$ …2023 · Numerical
Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R) Assertion (A) : An aqueous solution of $KOH$ when used for volumetric analysis, its concentration should be checked before…2023 · MCQ
$1 \times 1 0^{- 5} M AgNO_{3}$ is added to $AgBr$ of saturated solution of $AgBr$ . The conductivity of this solution at is $\times 1 0^{- 8} S m^{- 1}$ …2023 · Numerical