3 questions from 2024
Consider the dissociation of the weak acid \( \mathrm{HX} \) as given below
\( \mathrm{HX(aq)} \rightleftharpoons \mathrm{H^+(aq)} + \mathrm{X^-(aq)}, \\ K_a = 1.2 \times 10^{-5} \)
[ \( K_a \) : dissociation constant ]
The osmotic pressure of \( 0.03 \) \( \mathrm{M} \) aqueous solution of \( \mathrm{HX} \) at \( 300 \) \( \mathrm{K} \) is _______ \( \times 10^{-2} \) \( \mathrm{bar} \) (nearest integer).
[Given: \( R = 0.083 \mathrm{L \, bar \, mol^{-1} \, K^{-1}} \) ]
An artificial cell is made by encapsulating \( 0.2 \, \text{M} \) glucose solution within a semipermeable membrane. To osmotic pressure developed when the artificial cell is placed within a \( 0.05 \, \text{M} \) solution of NaCl at \( 300 \, \text{K} \) is _________ \( \times 10^{-1} \) bar. (nearest integer) . [Given : \( R = 0.083 \, \text{L bar mol}^{-1} \, \text{K}^{-1} \) ]. Assume complete dissociation of NaCl.
\( 2.5 \, \text{g} \) of a non-volatile, non-electrolyte is dissolved in \( 100 \, \text{g} \) of water at \( 25^\circ \text{C} \). The solution showed a boiling point elevation by \( 2^\circ \text{C} \). Assuming the solute concentration is negligible with respect to the solvent concentration, the vapor pressure of the resulting aqueous solution is ______ \( \text{mm of Hg} \) (nearest integer)
[Given: Molal boiling point elevation constant of water (\( K_b \)) \( = 0.52 \, \text{K} \cdot \text{kg mol}^{-1} \), \( 1 \) atm pressure \( = 760 \) \( \text{mm of Hg} \), molar mass of water \( = 18 \, \text{g mol}^{-1} \) ]
