Which of the following aqueous solutions has the highest freezing point?

If $0.072 \ g-atom$ of sulfur is dissolved in $100 \ g$ of solvent $(K_f = 7.00)$,the depression in freezing point is $0.84 \ ^\circ C$. The molecular formula of sulfur in the solution is .............

Elements $X$ and $Y$ form two non-volatile compounds ($XY$ and $XY_3$). When $10 \ g$ of $XY$ is dissolved in $50 \ g$ of ethanol,the depression in freezing point $(\Delta T_{f})$ is $5.333 \ K$. When $10 \ g$ of $XY_3$ is dissolved in $50 \ g$ of ethanol,the $\Delta T_{f}$ is $2.2857 \ K$. What are the atomic weights of $X$ and $Y$ respectively? $(K_{f} = 2 \ K \ kg \ mol^{-1})$

$A$ solution of a nonvolatile solute is obtained by dissolving $1 \ g$ in $100 \ g$ of solvent,which decreases its freezing point by $0.3 \ K$. Calculate the cryoscopic constant of the solvent if the molar mass of the solute is $60 \ g \ mol^{-1}$.

$2.0 \ g$ of a non-electrolyte dissolved in $100 \ g$ of benzene lowers the freezing point of benzene by $1.2 \ K$. The freezing point depression constant of benzene is $5.12 \ K \ kg \ mol^{-1}$. The molar mass of the solute is:

Which of the following formulae is used to calculate the depression in freezing point?