In alkaline medium, the reduction of permanganate anion involves a gain of _____ electrons.
Correct Answer: 3
Solution and Explanation
The reduction of permanganate anion (MnO$_4^-$) in alkaline medium involves the following process:
\[ \text{MnO}_4^- \, (\text{oxidation state of Mn} = +7) \rightarrow \text{Mn}^{4+} \, (\text{oxidation state of Mn} = +4) \] The reduction from Mn$^{7+}$ to Mn$^{4+}$ involves the gain of 3 electrons, as the change in oxidation number is from +7 to +4.
Therefore, the reduction of permanganate anion involves the gain of 3 electrons.
Top Questions on electron displacement effects
Given below are two statements:
Statement I: The conversion proceeds well in a less polar medium. \[ {CH}_3{CH}_2{CH}_2{CH}_2{Cl} \xrightarrow{{HO}^-} {CH}_3{CH}_2{CH}_2{CH}_2{OH} + {Cl}^- \] Statement II: The conversion proceeds well in a more polar medium. \[ {CH}_3{CH}_2{CH}_2{CH}_2{Cl} \xrightarrow{{R}_3{N}} {CH}_3{CH}_2{CH}_2{CH}_2{NH}_2 + {Cl}^- \] In the light of the above statements, choose the correct answer from the options given below:- JEE Main - 2025
- Chemistry
- electron displacement effects
- Which of the following shows resonance but not hyperconjugation?
- MHT CET - 2025
- Chemistry
- electron displacement effects
- Which of the following is more soluble in water at 298 K?
- KEAM - 2025
- Chemistry
- electron displacement effects
- Which among the following shows -R effect?
- KEAM - 2025
- Chemistry
- electron displacement effects
- Which of the following shows resonance but not hyperconjugation?
- MHT CET - 2025
- Chemistry
- electron displacement effects
Questions Asked in JEE Main exam
Consider the following sequence of reactions :
Molar mass of the product formed (A) is ______ g mol\(^{-1}\).- JEE Main - 2025
- Organic Chemistry
- A group 15 element forms \( d\pi - d\pi \) bond with transition metals. It also forms a hydride, which is the strongest base among the hydrides of other group members that form \( d\pi - d\pi \) bonds. The atomic number of the element is ________________________.
- JEE Main - 2025
- Chemical bonding and molecular structure
- Let \( M \) denote the set of all real matrices of order 3 x 3 and let \( S = \{-3, -2, -1, 1, 2\} \). Let
\( S_1 = \{A = [a_{ij}] \in M : A = A^T \text{ and } a_{ij} \in S, \forall i, j\} \),
\( S_2 = \{A = [a_{ij}] \in M : A = -A^T \text{ and } a_{ij} \in S, \forall i, j\} \),
\( S_3 = \{A = [a_{ij}] \in M : a_{11} + a_{22} + a_{33} = 0 \text{ and } a_{ij} \in S, \forall i, j\} \).
If \(n(S_1 \cup S_2 \cup S_3) = 125\), then \( \alpha \) equals:- JEE Main - 2025
- Linear Algebra
- Let the lines \[ 3x - 4y - \alpha = 0, \quad 8x - 11y - 33 = 0, \quad 2x - 3y + \lambda = 0 \] be concurrent. If the image of the point \( (1, 2) \) in the line \[ 2x - 3y + \lambda = 0 \text{ is } \left( \frac{57}{13}, \frac{-40}{13} \right), \text{ then } |\alpha \lambda| \text{ is equal to:} \]
- JEE Main - 2025
- Matrices and Determinants
In the first configuration (1) as shown in the figure, four identical charges \( q_0 \) are kept at the corners A, B, C and D of square of side length \( a \). In the second configuration (2), the same charges are shifted to mid points C, E, H, and F of the square. If \( K = \frac{1}{4\pi \epsilon_0} \), the difference between the potential energies of configuration (2) and (1) is given by:
- JEE Main - 2025
- Electromagnetic Field (EMF)