A solution contains ${Fe^{2+}, Fe^{3+}}$ and $I^-$ ions. This solution was treated with iodine at ${ 35^{\circ} C. E^{\circ}}$ for ${Fe^{3+} /Fe^{2+}}$ is $+0.77 \, V$ and $E^{\circ}$ for $I_2/2I^- = 0.536 \, V.$
The favourable redox reaction is-
- ${Fe^{2+}}$ will be oxidized to $ {Fe^{3+}}$
- $I_2$ will be the reduced to $I^-$
- There will be no redox reaction
- $I^-$ will be oxidized to $I_2$
The Correct Option is D
Solution and Explanation
Top Questions on Electrochemistry
Standard electrode potential for \( \text{Sn}^{4+}/\text{Sn}^{2+} \) couple is +0.15 V and that for the \( \text{Cr}^{3+}/\text{Cr} \) couple is -0.74 V. The two couples in their standard states are connected to make a cell. The cell potential will be:
To calculate the cell potential (\( E^\circ_{\text{cell}} \)), we use the standard electrode potentials of the given redox couples.
Given data:
\( E^\circ_{\text{Sn}^{4+}/\text{Sn}^{2+}} = +0.15V \)
\( E^\circ_{\text{Cr}^{3+}/\text{Cr}} = -0.74V \)- CBSE CLASS XII - 2025
- Chemistry
- Electrochemistry
- (a) Write the cell reaction and calculate the e.m.f. of the following cell at 298 K: \[ \text{Sn}(s) \mid \text{Sn}^{2+} (\text{0.004 M}) \parallel \text{H}^+ (\text{0.02 M}) \mid \text{H}_2 (\text{1 Bar}) \mid \text{Pt}(s) \] (Given: \( E^\circ_{\text{Sn}^{2+}/\text{Sn}} = -0.14 \, \text{V}, E^\circ_{\text{H}^+/\text{H}_2} = 0.00 \, \text{V} \)) \vspace{5pt}
- CBSE CLASS XII - 2025
- Chemistry
- Electrochemistry
(a.)Write the anode and cathode reactions and the overall cell reaction occurring in a lead storage battery during its use.
- CBSE CLASS XII - 2025
- Chemistry
- Electrochemistry
- The charge required for the reduction of 1 mol of \( MnO_4^- \) to \( MnO_2 \) is
- CBSE CLASS XII - 2025
- Chemistry
- Electrochemistry
- Calculate \( \Lambda_m^0 \) for acetic acid and its degree of dissociation (\( \alpha \)) if its molar conductivity is 48.1 \( \Omega^{-1} \, \text{cm}^2 \, \text{mol}^{-1} \).
Given that
\( \Lambda_m^0 (\text{HC}) = 426 \, \Omega^{-1} \, \text{cm}^2 \, \text{mol}^{-1} \),
\( \Lambda_m^0 (\text{NaCl}) = 126 \, \Omega^{-1} \, \text{cm}^2 \, \text{mol}^{-1} \),
\( \Lambda_m^0 (\text{CH}_3\text{COONa}) = 91 \, \Omega^{-1} \, \text{cm}^2 \, \text{mol}^{-1} \).- CBSE CLASS XII - 2025
- Chemistry
- Electrochemistry
Questions Asked in NEET exam
- Match List I with List II
List-I
(Reaction)List-II
(Reagents/Condition)(A) 
(I) 
(B) 
(II) CrO3 (C) 
(III) KMnO4/KOH, \(\Delta\) (D) 
(IV) (i) O3
(ii) Zn-H2O
Choose the correct answer from the options given below:- NEET (UG) - 2024
- Chemical Reactions
If the monochromatic source in Young's double slit experiment is replaced by white light,
1. There will be a central dark fringe surrounded by a few coloured fringes
2. There will be a central bright white fringe surrounded by a few coloured fringes
3. All bright fringes will be of equal width
4. Interference pattern will disappear- NEET (UG) - 2024
- Youngs double slit experiment
- Arrange the following elements in increasing order of electronegativity:
N, O, F, C, Si
Choose the correct answer from the options given below:- NEET (UG) - 2024
- Modern Periodic Law And The Present Form Of The Periodic Table
- The work done during reversible isothermal expansion of one mole of hydrogen gas at 25oC from a pressure of 20 atm to 10 atm is:
(Given R = 2.0 cal K-1 mol-1)- NEET (UG) - 2024
- Gas laws
- A horizontal force 10 N is applied to a block 4 as shown in figure. The mass of blocks A and B are 2 kg and 3 kg, respectively. The blocks slide over a frictionless surface. The force exerted by block A on block B is:
- NEET (UG) - 2024
- Friction
Concepts Used:
Electrochemical Cells
An electrochemical cell is a device that is used to create electrical energy through the chemical reactions which are involved in it. The electrical energy supplied to electrochemical cells is used to smooth the chemical reactions. In the electrochemical cell, the involved devices have the ability to convert the chemical energy to electrical energy or vice-versa.
Classification of Electrochemical Cell:
Cathode
- Denoted by a positive sign since electrons are consumed here
- A reduction reaction occurs in the cathode of an electrochemical cell
- Electrons move into the cathode
Anode
- Denoted by a negative sign since electrons are liberated here
- An oxidation reaction occurs here
- Electrons move out of the anode
Types of Electrochemical Cells:
Galvanic cells (also known as Voltaic cells)
- Chemical energy is transformed into electrical energy.
- The redox reactions are spontaneous in nature.
- The anode is negatively charged and the cathode is positively charged.
- The electrons originate from the species that undergo oxidation.
Electrolytic cells
- Electrical energy is transformed into chemical energy.
- The redox reactions are non-spontaneous.
- These cells are positively charged anode and negatively charged cathode.
- Electrons originate from an external source.