| LIST-I (Cell) | LIST-II (Use/Property/Reaction) |
|---|---|
| A. Leclanche cell | IV. Reaction at anode Zn → Zn2+ + 2e- |
| B. Ni-Cd cell | III. Rechargeable |
| C. Fuel cell | I. Converts energy of combustion into electrical energy |
| D. Mercury cell | II. Does not involve any ion in solution and is used in hearing aids |
In this question, we need to match the cells listed in List-I with their corresponding uses, properties, or reactions from List-II. Let's analyze each one:
Therefore, the correct answer is A-IV, B-III, C-I, D-II, which matches each cell type from List-I with the correct description or use from List-II.
A. Leclanche Cell: This is a primary cell where the reaction at the anode is: \[ \text{Zn} \rightarrow \text{Zn}^{2+} + 2e^- \] Thus, it matches IV.
B. Ni-Cd Cell: The nickel-cadmium cell is a rechargeable secondary cell commonly used in portable devices. Thus, it matches III.
C. Fuel Cell: Fuel cells convert the energy of combustion (e.g., hydrogen and oxygen) into electrical energy. Thus, it matches I.
D. Mercury Cell: Mercury cells are small, primary cells commonly used in hearing aids, and they do not involve any ion in solution.Thus, it matches II.
Final Match: A-IV, B-III, C-I, D-II.

Consider the above electrochemical cell where a metal electrode (M) is undergoing redox reaction by forming $M^+$ ($M \to M^+ + e^-$). The cation $M^+$ is present in two different concentrations $c_1$ and $c_2$ as shown above. Which of the following statement is correct for generating a positive cell potential?
MX is a sparingly soluble salt that follows the given solubility equilibrium at 298 K.
MX(s) $\rightleftharpoons M^{+(aq) }+ X^{-}(aq)$; $K_{sp} = 10^{-10}$
If the standard reduction potential for $M^{+}(aq) + e^{-} \rightarrow M(s)$ is $(E^{\circ}_{M^{+}/M}) = 0.79$ V, then the value of the standard reduction potential for the metal/metal insoluble salt electrode $E^{\circ}_{X^{-}/MX(s)/M}$ is ____________ mV. (nearest integer)
[Given : $\frac{2.303 RT}{F} = 0.059$ V]

