Answer
See the answer below.
Work Step by Step
Vapor pressure depression and boiling point elevation are proportional to $i.m$ and assuming total ionic dissociation, i is the number of ions per compound:
a) ethylene glycol (nonionic) 0.35 m
b) sugar (nonionic) 0.50 m
c) KBr $2\times 0.20\ m=0.40\ m$
d) Na2SO4 $3\times 0.20\ m=0.60\ m$
i) $d\lt b\lt c\lt a$
ii) $a\lt c\lt b\lt d$
