Match the boiling point with `K_(b)` for x,y and z if molecular weight of x,y and z are same.
`{:("liquid",B "point",K_(b)),(x,100,0.68),(y,27,0.53),(z,253,0.98):}`

Explanation

Since `K_b =(RT_b^2)/(1000 DeltaH_("vap")//M_("solvent"))` , we have
`K_b=(RT_b)/(1000((DeltaH_("vap"))/(T_b)//M_("solvent"))`
[`(DeltaH_("vap"))/(T_b)` is taken to be constant as per Trouton's rule]
`rArr K_b prop T_b`
Thus, we have
`K_b (X) = 0.73 kg mol^(-1), K_b(Y) = 0.53 Kg k Mol ^(-1), K_b(Z) = 0.98 kg K mol ^(-1)`