Q.

A solution containing 10 g of an electrolyte AB2 in 100 g of water boils at 100.52C°. The degree of ionization of the electrolyte (α) is _____×10-1. (nearest integer)

[Given : Molar mass of AB2=200g mol-1Kb (molal boiling point elevation const. of water) = 0.52 K kg mol-1, boiling point of water = 100°C; AB2 ionises as AB2A2++2B-]                [2024]


Ans.

(5)

                ΔTb=Tb-Tb°=(100.52-100)K=0.52K

                imkb=0.52K

                iwsolute×1000Msolute×Wsolvent(in g)kb=0.52K

                i10×1000200×100×0.52=0.52

                i=2

                AB2A2++2B-

               i=1+(n-1)α

              2=1+(3-1)α

             α=0.5=5×10-1