What is the elevation in boiling point for a one molal solution of a solute in a solvent called?

The elevation in boiling point for one molal solution of a solute in a solvent is called

Which of the following formulas correctly gives the value of the ebullioscopic constant $(K_{b})$?

Calculate the molality of a solution of a non-volatile solute if the boiling point of the solution and the molal elevation constant for the solvent are $319.8 \text{ K}$ and $2.5 \text{ K kg mol}^{-1}$ respectively. [Boiling point of pure solvent $= 319.5 \text{ K}$]

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 $5.0 \, K \, kg \, mol^{-1} ]$

If $10 \ g$ of a solute (molar mass $= 100 \ g/mol$) is dissolved in $100 \ g$ of water,then the molal elevation constant $K_b$ of the solvent will be equal to: