At the freezing point of a solution containing a nonvolatile solute,which of the following are in equilibrium?

$K_{f}$ (water) $= 1.86 \ K \ kg \ mol^{-1}$. The temperature at which ice begins to separate from a mixture of $10$ mass $\%$ ethylene glycol is (in $^{\circ} C$)

What should be the freezing point of an aqueous solution containing $17 \ g$ of $C_2H_5OH$ in $1000 \ g$ of water? (Given: $K_f$ of water = $1.86 \ K \ kg \ mol^{-1}$)

$A$ solution containing $8.0 \, g$ of nicotine in $92 \, g$ of water freezes $0.925 \, ^{\circ}C$ below the normal freezing point of water. If the molal freezing point depression constant,$k_f = 1.85 \, ^{\circ}C \, kg \, mol^{-1}$,then the molar mass of nicotine is $...$

$1.00 \ g$ of a non-electrolyte solute dissolved in $50 \ g$ of benzene lowered the freezing point of benzene by $0.40 \ K$. The ${K_f}$ for benzene is $5.12 \ K \ kg \ mol^{-1}$. The molecular mass of the solute will be ............ $g \ mol^{-1}$.

During the freezing of a solution at its freezing point,which of the following equilibria exists?