Question

The molal elevation constant is the ……. In boiling point produced on dissolving one mole solute in 1000 g of solvent.

Answer 1

Hint: Solution is mainly composed of solute and solvent where solute is that which is present in less amount i.e. to be dissolved and solvent in which it get dissolved i.e. present in higher amount and solute and solvent both make solution.

Complete answer:
The molal elevation constant is defined as the elevation in the boiling point of a solvent when one mole of a non-volatile solute is dissolved in it per kilogram of solvent. The unit of molal elevation constant is given as $Kgmo{{l}^{-1}}$.
Molal elevation constant is derived experimentally and it has been shown that the elevation in the boiling point which is represented by the symbol $\Delta {{T}_{b}}$for dilute solutions is directly proportional to the molal concentration of solute in the solution.
Therefore, we can write the equation that $\Delta {{T}_{b}}\propto m$
Directly proportional will change into constant of proportionality represented by the symbol${{K}_{b}}$,
$\Delta {{T}_{b}}={{K}_{b}}m$
Here, m is molality or the number of moles of the solute dissolved in a kg of solvent. ${{K}_{b}}$ ​is the molal elevation constant.
Hence from this we can say that the molal elevation constant is the elevation in boiling point produced on dissolving one mole solute in 1000 g of solvent.

Note:
Molality is also known by molal concentration which determines the concentration of a solute by mass of the solvent in a solution. Molality is generally mass of the solvent i.e. number of solvent moles per kilogram. While molarity is volume of the solvent.