What happens to the freezing point of benzene when a small quantity of naphthalene is added to it?

If the freezing point of a $5\% \ w/w$ aqueous solution of sucrose is $271 \ K$ and pure water has a freezing point of $273.15 \ K$,then calculate the freezing point of a $5\% \ w/w$ aqueous solution of glucose. (in $K$)

$x$ moles of $CO(NH_2)_2$ are present in $1200 \ g$ of water. If the freezing point of the solution is $-4.02 \ ^oC$,calculate the value of $x$. Given $k_f \ (H_2O) = 1.86 \ K \ kg \ mol^{-1}$.

The freezing point of an aqueous solution containing $17 \ g$ of $C_2H_5OH$ in $1000 \ g$ of water is ......... $^oC$. (Given $K_f$ of water $= 1.86 \ K \ kg \ mol^{-1}$)

Under identical conditions,which aqueous solutions have the same freezing point? (Molecular mass of urea $= 60 \ u$ and glucose $= 180 \ u$)

$1.00 \text{ g}$ of a non-electrolyte solute dissolved in $50 \text{ g}$ of benzene lowered the freezing point of benzene by $0.40 \text{ K}$. The freezing point depression constant of benzene is $5.12 \text{ K kg mol}^{-1}$. Find the molar mass of the solute.