The elevation in boiling point of a $0.25 \ molal$ aqueous solution of a substance is $(K_b = 0.52 \ K \ kg \ mol^{-1})$. (in $K$)

When $3.00 \, g$ of a substance $'X'$ is dissolved in $100 \, g$ of $CCl_4$,it raises the boiling point by $0.60 \, K$. The molar mass of the substance $'X'$ is $..... \, g \, mol^{-1}$. (Nearest integer).
$[$ Given $K_b$ for $CCl_4$ is $5.0 \, K \, kg \, mol^{-1} ]$

$A$ solution of $1$ molal concentration of a solute will have maximum boiling point elevation when the solvent is

$A$ solution containing $2 \ g$ of a non-volatile solute in $20 \ g$ of water boils at $373.52 \ K$. The molecular mass of the solute is $....... \ g \ mol^{-1}$. (Nearest integer) Given,water boils at $373 \ K$,$K_b$ for water $= 0.52 \ K \ kg \ mol^{-1}$.

Calculate the molal elevation constant $(K_b)$ of a solvent if the boiling point of a $0.12 \ m$ solution is $319.8 \ K$ (Boiling point of pure solvent = $319.5 \ K$).

What will be the boiling point of $1 \ m$ urea solution in $K$ unit? $(K_b = 0.52 \ K \ kg \ mol^{-1})$