Arrange the following aqueous solutions in order of decreasing freezing point. (The last three are all assumed to dissociate completely into ions in water.)
(a) 0.20 m ethylene glycol (nonvolatile, nonelectrolyte)
(b) 0.12 m K₂SO₄
(c) 0.10 m MgCl₂
(d) 0.12 m KBr