Define the following terms :
(a) Molarity
(b) Molal elevation constant `(K_(b))`

Explanation

(a) Molarity : Molarity of a substance in a solutions is equal to the number of moles of the substance present in one litre of the solution.
i.e. Molarity `=("No. of moles of substance")/("Volume of solution in L")`
(b) Molal elevation constant : It is also called ebullioscopic constant. It is equal to the change in boiling point of one molar solution.
`Delta" Tb = Kb.m"`
So, when Molarity `=1,Delta"Tb = Kb"`