3 questions from 2021
At \( 298 \, \text{K} \), the limiting molar conductivity of a weak monobasic acid is \( 4 \times 10^2 \, \text{S cm}^2 \, \text{mol}^{-1} \). At \( 298 \, \text{K} \), for an aqueous solution of the acid the degree of dissociation is \( \alpha \) and the molar conductivity is \( y \times 10^2 \, \text{S cm}^2 \, \text{mol}^{-1} \). At \( 298 \, \text{K} \), upon \( 20 \) times dilution with water, the molar conductivity of the solution becomes \( 3y \times 10^2 \, \text{S cm}^2 \, \text{mol}^{-1} \).
The value of \( \alpha \) is ____________.
At \( 298 \, \text{K} \), the limiting molar conductivity of a weak monobasic acid is \( 4 \times 10^2 \, \text{S cm}^2 \, \text{mol}^{-1} \). At \( 298 \, \text{K} \), for an aqueous solution of the acid the degree of dissociation is \( \alpha \) and the molar conductivity is \( y \times 10^2 \, \text{S cm}^2 \, \text{mol}^{-1} \). At \( 298 \, \text{K} \), upon \( 20 \) times dilution with water, the molar conductivity of the solution becomes \( 3y \times 10^2 \, \text{S cm}^2 \, \text{mol}^{-1} \).
The value of \( y \) is ____________.
Some standard electrode potentials at \( 298 \,\text{K} \) are given below:
\( \text{Pb}^{2+}/\text{Pb} - 0.13 \,\text{V} \)
\( \text{Ni}^{2+}/\text{Ni} - 0.24 \,\text{V} \)
\( \text{Cd}^{2+}/\text{Cd} - 0.40 \,\text{V} \)
\( \text{Fe}^{2+}/\text{Fe} - 0.44 \,\text{V} \)
To a solution containing \( 0.001 \,\text{M} \) of \( X^{2+} \) and \( 0.1 \,\text{M} \) of \( Y^{2+} \), the metal rods \( X \) and \( Y \) are inserted \( (\text{at } 298 \,\text{K}) \) and connected by a conducting wire. This resulted in dissolution of \( X \). The correct combination(s) of \( X \) and \( Y \), respectively, is(are):
\( (\text{Given: Gas constant, } R = 8.314 \,\text{J K}^{-1}\text{mol}^{-1}, \text{ Faraday constant, } F = 96500 \,\text{C mol}^{-1}) \)
