Why zinc sulphate solubility is higher in ethylene glycol than water?
Zinc is an amphoteric metal which means it can dissolve both in acidic and basic conditions. However, neutral pH is the transition point. Please see this article Recovery of Rare Earths from Waste Cathode Ray Tube (CRT) Phosphor Powder by Selective Sulfation Roasting and Water Leaching on its behavior in water and eg. I believe the reason is that in eg there is no mechanism for zinc to form insoluble hydroxide complexes which will decrease the solubility of zinc. But in ethylene glycol you simply cannot form hydroxides..