What is the freezing point depression constant of a solvent, \( 50 \, \mathrm{g} \) of which contain \( 1 \, \mathrm{g} \) non-volatile solute (molar mass \( 256 \, \mathrm{g\,mol^{-1}} \)) and the decrease in freezing point is \( 0.40 \, \mathrm{K} \)?
\(1.24\, \text{g}\) of \(\mathrm{AX}_2\) (molar mass \(124\, \text{g mol}^{-1}\)) is dissolved in \(1\, \text{kg}\) of water to form a solution with boiling point of \(100.0156^\circ \text{C}\), while \(25.4\, \text{g}\) of \(\mathrm{AY}_2\) (molar mass \(250\, \text{g mol}^{-1}\)) in \(2\, \text{kg}\) of water constitutes a solution with a boiling point of \(100.0260^\circ \text{C}\).
\(K_b(\mathrm{H_2O}) = 0.52\, \text{K kg mol}^{-1}\)
Which of the following is correct?
