When a solute is added to a solvent,the freezing point of the solution decreases to $1.86 \ K$. What is the value of $\Delta T_b$? $[K_f = 1.86, K_b = 0.512]$

Select the correct statement.

The elevation in boiling point for $1 \ m$ solution of non-volatile solute $A$ is $3 \ K$. The depression in freezing point for $2 \ m$ solution of $A$ in the same solvent is $6 \ K$. The ratio of $K_{b}$ and $K_{f}$ i.e.,$K_{b} / K_{f}$ is $1 : X$. The value of $X$ is [nearest integer].

Calculate the freezing point in $^oC$ of an aqueous solution of urea that boils at $100.18\,^oC$. $(K_f = 1.86\, ^oC\, m^{-1}, K_b = 0.512\,^oC\, m^{-1})$

The solution from the following with the highest depression in freezing point (lowest freezing point) is:

At $40\,^oC$,the vapour pressure (in torr) of a solution of methyl alcohol $(A)$ and ethyl alcohol $(B)$ is represented by: $P_s = 120 X_A + 138$,where $X_A$ is the mole fraction of methyl alcohol. The values of $\lim_{X_A \to 0} (P_B^0)$ and $\lim_{X_B \to 0} (P_A^0)$ are: